The comments/feedback is crazy!! Thank you all for your awesome ideas, suggestions, tips, tricks and whatnot. Really awesome to hear so many advices, opinions. I think part 2 of this project will be a "community" video in which I will partly test your ideas. Will be lots of fun. But it will certainly take a while until I get to that. So stay tuned ;-)
I don't understand why you didn't mount the lights under each step and put pressure sensors in the floor at the top and bottom... it's what I did at least.
@@philosoaperit would indeed be the easiest, but that would probably add a bunch of wiring that you can't really hide unless you start drilling and/or creating some slots.
Specially since a considerable part of those end up being debunked as just not showing the tons of fixes behind the scenes, or downright faked to work.
The reason more channels don't show all their failed attempts, is probably mostly about to saving time. As we know - it takes quite a bit of luck for a project to work right away. Troubleshoting and possibly redesigning a few times is usually a part of designing something - which often takes quite a bit of time on it's own. Now if making video documenting each step, redraw scematics to show of every change then edit all those video shorts, the project may take "forever" to get done, as more time will often be spent making the video, than on the project it self. It's just so much easier to just wait with the filmning and editing, until everything is already finished and tested - then make a detailed video how it works with scematics and how to build. But yes, it can still be of interest those who take their time to even show the failed attempts and for those new to electronics, it can be very useful
I found where you have the problem!!!! I also double checked with a electronics technician that has 50+ years in component level troubleshooting and high frequency circuit design who just happens to be my father that my suspicions where correct. He was able to give a solution and explain why it was happening along with why you were getting that specific frequency. Your driver circuit for the LED needs a second filter on the other side of the coil (U6) but before the diode (D3). In the current configuration, with the PWM being fed into there, you are pumping a RLC circuit in a single direction that has no where to release its energy other than ground and the power monitoring pin of the micro-controller (pin PA6 of part U3). Since it is going though a series of diodes, it is reflecting off of them and this is causing a doubling of the frequency. If you run a RLC calculation f = 1 / [2π × √(L × C)], you get 7.341 kHz for with the ideal component values and 14.682 kHz for the doubled, which is within 95% of the ideal component values, so accounting for the variance in the parts and the sub-harmonics we are seeing on the oscilloscope, this is pretty good proof that the hypothesis is correct. To test it further, removing a single unit for testing would be advisable and then replacing filter capacitor C10 with a different value or adding one in parallel to change the value and then checking with an oscilloscope might be a possible way to check for it. It is also possible that the oscillating circuit is internal to the LED driver IC, so adding this cap may do nothing, but adding the filter at the location that I specify as the solution is going to still work as that is the correct filter location in the circuit. You are going to need to put rejection filters between U6 and D3 that only pass DC and the fundamental frequency for your PWM signal. You could also get away with a low pass filter if the fundamental frequency for the PWM is low enough. I would suggest changing the PWM frequency to a lower value so that you can just use the low pass filter as high frequency noise is easiest to filter out. The datasheet for the micro-controller shows how to do this. As long as the resulting frequency is at least 10% below 7 kHz it should get rid of the noise. Assuming you are on the default settings for it, you should be well below that, but double check. Now as to the why on why this was causing so many problems with the micro-controller. The default clock speed of the micro controller might be set to 16 kHz (+/- 3% over voltage range and +/- 2% over temp. range) by default, so, if you have a signal on the other end of the PWM output pin that is close to that and really noisy while being unstable, like you have, and that pin isn't optically isolated (which this micro-controller doesn't have optical isolation on its I/O pins and problems like this are why you want optically isolated I/O pins) the interference can be feeding back through the circuit and causing problems with the PWM circuit. 97% of 16 kHz is 15.52 kHz, which is close enough for some signal coupling, so it can feed back into the circuit and cause the clock for the PWM to start having errors that the processor will have to correct, which will cause all sorts of strange behavior. I would change the internal clock that the PWM is using to the 20 kHz mode that the micro-controller has the option of using to just completely take it out of using a similar frequency. Make sure that the fundamental frequency that gets produced by the PWM still stays below the 7 kHz range using the equations given in the datasheet for how resolution and clock selection and clock type result in the output PWM signal's fundamental frequency. Just putting the filter in will probably fix most of the noise, but lowest noise possible is the best thing to do when dealing with micro-controllers. I would suggest in future only using micro-controllers with optically isolated outputs and always make sure that if you have a cap and coil in series in an oscillating circuit with diodes that you have a filter for both directions that the coil can discharge unless you are trying to make it oscillate or build a higher voltage.
U1 is the LED driver at 7:30. The circuit he used is exactly the same as Diode's reference design, it is just drawn a bit weird. The chip itself is a bit weird for using high-side sensing instead of low-side. Aside from that, it is a completely ordinary buck regulator. The only thing "missing" is an optional filter capacitor across the LEDs at the regulator, which may help with EMI when the LED current loop is taking a ~35cm trip around the board.
@@teardowndan5364 I know it is buck converter and it is going to have a ring to it there unless you add a filter where I said to put it, they all do and that is the frequency of that specific circuit's oscillation. The problem he is getting is that the frequency it is ringing at is really close to the clock source the PWM circuit is using in the micro-controller. This is a problem because the micro controller doesn't have optically isolated I/O pins, so any high frequency signal that gets on one of those pins that is close to one of the frequencies the controller IC uses, it will propagate into it and start causing errors intermittently. He might be able to get away with just changing the clock value in the controller from 16 kHz to 20 kHz. If not, he needs to filter off that noise. A buck converter circuit is noisy. Connecting it to a digital circuit or a circuit with active components can result in weird behaviors since you are going to get noise from the buck converter that is in the kHz to MHz range, both of which are in the RF range where they start treating everything as active components, even the case of the circuit, so when it gets into an IC, things get weird. I would use a different power source for driving the LEDs in this application next time or isolate the power supply from the micro controller, like with optical isolation.
@coolmonkey619 2 year degree at a technical college will do it. A BS or BA in electrical engineering will also cover it. You are probably going to need a 3.0 or higher GPA or at least paying attention to the topics of power supply supplies, digital circuits, and high-frequency circuits. Just for this problem, having a basic understanding of IC internal design and clock generating is also needed for this as well. Then you also need to understand micro controllers along with microprocessor error correction to see why the problem was so weird. I only confirmed my suspension about the problem with my father, who is a retired microwave telecom tech and designer because I could find the multiplier in the circuit that was giving the 15 kHz, but that is mainly because I would never have ran across this problem since my instructors warned me about the pitfalls of noisy power supplies and digital circuits along with micro-controllers needing the optical isolation or you can risk noise backfeeding into the I/Os or a transient coming in and frying the micro-controller.
@@KnightsWithoutATable If Diodes doesn't include any additional filtering, I am pretty sure it is because its engineers who work on this stuff full-time have done every analysis prescribed by best practices and have concluded that it is perfectly fine as-is for the IC's intended application and following applicable layout guidelines, which usually includes keeping all high-frequency stuff tightly packed, which it isn't when you have two LEDs in series spaced ~15cm apart and the traces in-between acting as an antenna. Just had a look at his PCB layout. The LED trace routing is an EMI disaster. The current return trace needs to be parallel with the source trace like a differential pair, not routed along opposite board edges! And those power traces are also running parallel to the data traces on the other board layer. Maximum EMI.
@@greatscottlab a tube of acrylic may help with channeling the emitting side of the diode, which can then be shielded with heatshrink. A 3D printed bracket to hold this in place sounds perfect. 🙂Perhaps the V2 PCB's could have some holes in them to allow for locating and/or installing these brackets or features, if only for those who need it getting the inspiration.
To be honest this was one of the most eye-opening of your videos to me. Seeing such a theoretically simple and trivial project experience issues due to noise and other things.
If you redesign the boards, it might be easier to use connectors to slide them together, soldering them all together will have to many failure points and you cant take it apart to diag and repair.
@@greatscottlab I was thinking a surface mount, right angle, pin header like M22-5330405 (found on digikey) for low profile easy connections. I’m sure you can find something like it cheaper and quicker on JLCPCB, but their connector page wouldn’t load for me.
@@greatscottlab also make them so that you can disconnect them without sliding out everything, maybe even make them 2mm smaller and glue them into place so that you can take them out easily
Honestly I think that idea could be commercialized pretty easily. If they are snap together all-in-one units that a do-it-yourselfer could easily accomplish... that would be a great selling product.
@greatscottlab LED Lighting Electronics Engineer here. I reviewed your project files and a few things: 1) put 0.1uF and 10uF cap on the input and output of your LED switcher. You actually need a high freq cap and lower freq cap to cover the freq range for input and output ripple 2) I like the 4-layer idea, but do 2 internal layers of ground, and only route on top and bottom. Also, make sure to sink a ground via right next to every signal line via (this will help the signal keep good ground reference and force the inductive coupling on the internal layers to follow a set path. Try to reduce the number of vias per net as much as possible (don't want added inductance) 3) Make sure to look at the recommended switcher layouts and make your switching nets small, and DO NOT let them go onto other layers (don't want to have inductive coupling between layers). Also, try and get ground between traces so you don't get cross talk. At the lengths of your PCBs, I'd expect you could get Volts worth of cross talk, even at sub 100MHz freq. 4) I'd add a common mode choke to the input of every PCB and a Pi-Filter too. It may be overkill, but for a few extra bucks you grantee each board isn't getting noise on the input. Make sure to route this all on the same layer as the connection between boards (so top layer for you). The shear length of the boards all ganged together is working against you and stray fields from surrounding power lines and appliances/electronics could get onto the boards and cause some weird behavior. Better to go all out and find you you don't need it then to find out you do need it haha. I highly recommend "philslab" on youtube as has some great videos giving best practices. The whole FEDEVEL group is very helpful for PCB design for EMI / EMC. Wish you the best of luck man! I love your videos and love the idea ;) Keep it up man!
The design of the data lines won't work as indended as described at 5:12, there should be one diode for each OUT pad, not one for both. In your current design, every other board is commoned together via the OUT-Line of the board in between: Board A In2↔Board B OUT1/OUT2 ↔Board C IN1/IN2 ↔Board D OUT1/OUT2↔Board E IN1/IN2... Most likely that's why all the boards were lit in most of your initial trouble shooting. The boards at the top of the stair (which later you found missbehaving) pulled all the other inputs low, until you introduced smaller pull-ups until the voltage drop was enougth to be registered as low.
I noticed that too. His outputs are connecting to outputs and his inputs are connecting to inputs in his drawing. If it's the same on the actual PCB, then that would explain a lot
When I made some under cabinet led tape lights integrate with doors and mains power about five years ago, I had a similar story. A "weekend project" spiraled into about 8 work days of effort and required a one year break for "finishing touches". I could not be happier with the results, even thought it needs another minor touch up. Your project is so much more ambitious and I cant wait to see how it turns out!
lol, it was quite funny. just like my wife, 'you are not going to put a solar light up here'. Our porch needed a motion light, and she insisted it not be visible, so I had to hide it all.
Thanks for sharing. Why didn't you use an addressable led stripe (e.g WS2812B) plus the sensors to know where is the person and only one microcontroller governing all of them?
You could use the WS2811 IC, it's the one that is in the neopixel, just replace the RGB LEDs with white LEDs, like that you can control 3 white LEDs with one data line. That way removes the need to have a constant-current source (or sink) to drive the LEDs with a PWM (or any switching power regulation), and then also removes the high frequency noise that could be induced in the circuit.
@@greatscottlab I'd just put in the WS2812/13 LEDs that have the IC built in, saves component cost and you can build in a april fools version where the stairs turns itself into a disco just 'because you can' :P
@3zuli @someguy4915 These options would also work, it will also allow to have red night light but I was supposing that @greatscottlab didn't want to have/use RGB LEDs and wanted better white LEDs.
I came accross this brilliant video a couple of weeks ago and absolutely loved it, including the issues and how you try to deal with them. All of a sudden, I don't feel alone anymore :). I found the idea very good, so I had to try it and sourced a few components and knoked up a few boards on the micro cnc and wired everything > I modified ever so slightly the schematic and the code to address some logic issue with the pin In and Out. On one board everything works, but as soon as you connect several boards they start firing up randomly. Like you I spent a bit of time trying to figure out what happened. My conclusion was that it was nothing to do with the noise on the in/out line. In fact the issue is the variance in the response from the VCNL4200 sensor from one unit to the next and also within the same unit!. So I finally got it to work by measuring a "reference threshold" in the setup of the code (so I might have different value for each sensor) and also by taking the average of 11 samples for each reading of the proxy sensor. That completely fixed my issue! (I think ;) ) If you are interrested in the code or schematic I can of course share it. Thanks again for your great work!
Frugal Engineer : This can be done with two proximity sensors, the 1st at the beginning of the staircase and the 2nd at the end. Keep the entire LED strip on until you pass the ladder. Use reliable MCU and LED drivers. As per my understanding, you don't want to manually turn on/off the house lights, and you don't want big bulbs to be lit
@@albertoandrescuevashiguera4304 We understand what he wants and that would make for a rather cool effect but seriously there's no need to overcomplicate lights in this way, especially when they're only going to be active for about a minute once or twice per night, I mean it's just for lighting stairs just leave them on all night at the lowest visible brightness...
@@albertoandrescuevashiguera4304 Doesn't make any difference, it serves the purpose, that's the only thing that should matter logically. Keep the LEDs on until you're done, not just the steps, but the entire staircase.
There is a concept humans have they call "aesthetics". A little weird to us, but it mainly means they like things just from their look and feel. More than that: This can differ in every one of them! To us it has a logical benefit, though: It covers the case where someone turns around on the stairs or two people go. Which would be no issue if both sides just trigger a timer, though.
I was going to make animated lights on my staircase but decided a simple "all on", when a person is detected, was safer. I used a multivibrator circuit to turn on the lights for 30 seconds, and re-trigger whenever motion is detected. Fancy lighting effects look cool, but are distracting and dangerous IMHO. I love your method for mounting the LEDs. I chose to do the massive wiring to each LED approach, lol.
Yea that's the I way. A local shop to me installed one of those sequencial stairs that was sequential in both the steps and the sides (not shure if it makes sense), and I found it super distracting going up those stairs until I sort of memorised them and got to go up without caring about the light.
I love that you show what didn't work. I'm still at the beginning and my first thought would be to illuminate the whole staircase dimly with a few presence detectors (including beginning & end) or use buttons for simplicity and use a timer to turn it off after a suitable amount of time. Illuminating each few steps individually seems like an anti-feature feature because we literally lookahead to plan our steps in advance.
This reminds me of a project I built back when I first started tinkering with electronics: A motion sensor based light controller with a PIR motion sensor. It worked beautifully most of the time, but whenever someone would flip on the light in the next room over, it would trigger the motion sensor resulting in the lights coming on in the middle of the night. I suspect I had similar issues with the input voltage fluctuating too much and confusing the sensor. Thank you for the great video, keep up the good work and don't give up!
maybe if he tried it with light diffusion material with narrow holes just for the sensor's diodes, I think its small enough to disappear when looking from a distance.
That's what I was thinking too - however a tube may not solve the issue as there may still be light reflected from other surfaces / feet. It might be an option, since you have comms between the boards, to activate the sensors one at a time so it effectively scans the stairs. Then each sensor will only receive it's own light.
THANK YOU SO MUCH for sharing your entire process - it is so refreshing to see setbacks and someone holding their hands up - too many people think experts know everything -crazily - this is the EXACT thing ive been thinking about doing - I'm so glad its not just me that gets stuck and frustrated so much you have to just walk away and come back with a fresh mind later. Thank you for sharing this - I would be VERY interested in the solution you come to when you do.
You have noise on the Input Pin (PA7) Add a 100nF capacitor between PA7 and GND. Place the capacitor close to the ATtiny402. When using long wires, in your case long traces, you made a Antenna. All input pins should have Capacitors on them, but the higher the capacitance, the lower the switching speed, so you'll have a lower transmission rate
VL53L1x is a Lidar sensor from ST. it worked well and came cheap at cost. Program the sensor to turn LEDs "ON" position for the next two LEDs. I learned many things from you.
It's immensely relieving for me to see that I'm not the only one who doesn't get it right immediately. Thank you GreatScott! And: would love to hear how you'll fix this (and I know you will!)
Oh man I LOVE the "we just got this staircase, you will not damage it in any way". Any tech man needs a woman like this to keep things sane. My girl does the same. You girl is a keeper :)
On a similar project that I worked on; we needed to send a signal across interconnected PCBs without limiting the number of boards that could be connected. We used a buffer IC to refresh the signal from board to board so no significant voltage would be lost if the user wanted to connect several boards together.
Well, I spent so much time on this project that I kind of had to make it into a video. And no, coding is not the problem because everything worked fine when testing with less units. I think EMC is the big problem here.
A bunch of sensors can mess with each other. I went with radar (Doppler GHz) at top and bottom, they are far enough to not see each other. Then you can turn on all the LEDs in sequence (away from motion) and control them all from nice microcontroller. Giving you tad more time to move past them. Then shut them down again in sequence. And those radar sensors are so awesome!! Oh, addressable LED’s could share power and data. And I agree, we love learning along side you. My projects go the same way! ;)
Can you maybe do a video about "Choosing the right microcontroller for your project"? Or generally explain how you search for a suitable microcontroller
It pretty much breaks down to the following: 1. Do you already own the expensive programmer for a particular brand of micro controller. (start looking here and use one unless there are litterally none that meet the other following requirements) 2. Consider the number of general I/O pins you need and if you need any special features like a DAC or audio peripherals (essentially anything you want built into the microcontroller and would rather not have it on a seperate IC) 3. Is the microcontroller fast enough / has enough flash memory for your program. If you're using Arduino consider a micro controller with at least 8KB of Flash so you have a good amount of room for your actual program. Also make sure it's fast enough to do what you need it to do if you're using an ISR for example to do something. Those are pretty much the basics for choosing a micro controller for a project.
My solution: Up and down is one HLK-LD2410, both connected to ESP8266. The bottom one has one pin connected to LED strip with WS2812 LEDs on the whole path of the stairs. Once motion is detected near the bottom one, the LEDs will light up from bottom to top. Once the motion is detected on the top one, it sends the signal to the bottom one and the stairs will light from top to bottom in "usual" walking pace. Works great, keeps the light on for next 5 seconds, to allow kids to, for example, find the entrance to bathroom, or to the next staircase, then the lights "go out" in the same way the came in. Works great, the whole solution costed less than $30, if I do not include the aluminum LED channels - those were the most expensive part of the project in the end :) And as this is radar, I have no problem with transparency of the plastic ;)
It took me three weeks four different tries with the programing (worse than you in that area). Finally went to a friend about the code he showed me that using a state machine was the best case and it mostly works. The issues on the board like noise and signal integrity were mostly the board layout and lack of proper filtering. I have built this in two different places, and for the most part they are still working. Had an LED go out on one about a year back. Mine are made to react to the step before being on or off state. Also had to angle the motion sensor up at a thirty five degree angle to keep the cats from playing with the lights. Peace
I feel your pain, my friend… we all have those frustrating project experiences. Thank you, for sharing yours. I’ll look at the files and think about this and send any thoughts later. Great video, as always! 👍😊👍
An addressable led strip with a ESP32 with WLED and two IR sensors (one on top of the staircase and one at the bottom) could do the trick relatively easy (even change the effect/brightness at certain times of day). Maybe even coupled with home assistent to intergrade in the smart home.
Had very similar idea back in 2021 while building my stairs. Wanted to do all just using analog discrete parts. Never actually got to it. Good luck with your project and thanks a lot for the kick I probably needed to get back to this project.
@@greatscottlab perhaps it might help to reduce the size of them, and for the ground plane to only really extend under the attiny and the LED controller IC. It might also help to run VCC and ground over an external (twisted?) wire pair, but that would somewhat defeat the purpose.
If not already done, it can be beneficial to connect the aluminum profile to GND and/or protective earth. This can reduce the "noise" fields by giving those a decent path to "conduct" to.
I LOVE THIS PROJECT!!! I know you feel frustrated by it but you definitely when through all the troubles and troubleshooting problems someone would have gone through when developing a small project and i love it!!!
You simply should enable only 1 distance sensor at a time, not all at once. Distance sensors are interfering with each other when they are simultaneously firing . Also most probably the distance sensors are the ones that create the noise.
But how do you activate only 1 at the time? To know if person is standing on the step you need for distance sensor to be turned on at all time and you have no idea from which direction up or down someone will go
Thanks for sharing your problems so others don't "fall" into the them. Engineering is all about iterating so no shame in prototyping. Can I suggest having LIN bus or another com line among all the sections so not only will they light up where you step but where you are going to step. The LIN bus would also help you debug so you only have to talk the primary chip to debug the entire strip.
I love the I tried it this way and it failed, and tried it another way and it failed over and over relentlessly. the break is going to help you piece together all those moments and you're probably going to discover the cause: whether it's some frequency, heavy pulldown, floating grounds etc. Kudos "Great Scott" for the endeavours.
Great project. I love the fact that you take us all through the design, build and problem solving and not just "look I build X and it's working". I can't wait to see how V2 gonna be.
That is such an excellent project! I see where you were headed with it, (and kudos for working as a carpenter for a bit- THAT can be quite frustrating if it's not something you do all the time!) I learned some things, and JLCPCB pricing info... I can't wait to get home so I can work on some original design boards to try them out! Don't feel bad, that try, fail, retry, walk away loop happens to all of us!
yeah I have the same problem with see through stairs. I had other ideas but seems we may move out potentially, so we'll see 6:50 just drill 2 small holes. makes it very directional and not false trigger
For the noise problem coming from the switching power supply, I suggest you to use shielded inductors. And maybe, you can also try to connect to ground the aluminium bar. It can act as a shield. I also suggest you to use some sort of connectors between the modules, instead of soldering them together, so if a module need to be replaced, you can do it easily.
Could the aluminum casing be causing shorts? At 9:01 you can see that there are some vias I think? Probably the back is just GND or something? Please correct me on why not. I am not very experienced with practical things in the electronics world.
This is great, Scott! As other comments mentioned, I would consider using addressable led strips, but also taking advantage of the different colors you can turn on. At night, the blue light is the one you should avoid, so you might turn on the leds on yellow color.
Hi! I looked at the project files to see if I could help with something and I think there are some issues with the daisy chain. Since in1 and in2 are basically the same wire and so are out1 and out2, connecting out2-in1 and out1-in2 causes issues if you have four boards or more. Let's say we have Board A firing up, it will send a signal to Board B through out2_A - in1_B, which will be seen by Board C through in2_B-out1_C and then fed to Board D through out2_C-in1_D leading to it firing up as well. That is what we see at 11:42 where every two boards light up when only one is triggered. It looks like there is another issue with the boards on the top of the staircase causing them to always be lit up, I don't know why for sure but because they seem to be able to lit up without always triggering the other boards down the staircase I would assume that the trigger doens't come from a wrong digitalWrite but rather a false positive digitalRead propably due to noise. I hope you can end up making the project work because the idea looks nice!
Thanks, excellent content! Some issues with the signalling are already well covered in the other comments but as an alternative, how about a simple analog circuit for the "signalling the neighbours"? You could have one common "sense" line, with a series resistor (eg. 1k), and another (eg. 1k) to the ground, in every PCB. The board (or boards) that detects movement would then pull the line up. This would create a voltage ladder circuit across all the other boards in the system. The "origin" board would have the sense signal at +3.3, next board seeing something less than half of that, and so on. I believe ATtiny can easily source/sink the required 5..10 mA from the output pins, and has a 10 bit ADC to measure the voltage (*). This would require only one pin and connection between the boards. Noise filtering, on/off delay and range (ie. how many adjacent boards to turn on) could then be tuned in the software. (*) edit: for example two boards triggering, the circuit and voltages would be like tinyurl.com/27fdw7yt (circuitjs).
I did a similar project with a lightstrip and two movement sensors, one at the top and one at the bottom. This way you can program the lightstrip to light up gradually starting at the sensor which was activated. Looks pretty smooth. And quite easy to implement!
bro belive it or not but i just finished my new home heavy construction and today i put my pover cables inside of wall for stairs led lights. Come home for searching about it and first video was yours. Its not a first that you hellping me almost instantly. Thanks, love from Azerbaijan
I love this project in particular. One thing that I could try if I was you is to try to optically isolate the sensors in a sort of rectangular tube, because it seems to me that the sensors are receiving bouncing IR from each one as you move into the stairs. Happy debugging!
You are indeed making me feel my age. When I was young, from birth to age 12, we lived on what was called the "home place' an old house built by grandfather in 1910. While REA came through and put a high line pole in our yard, nobody bothered to run a wire to the house or for that matter wire the house for power. So it was, when we went to bed in the 2 rooms that were "upstairs" we climbed the steps which were painted white but have a black mat on each step so there was pretty much no light other then that small flickering lamp that mom had lite in the kitchen below, that being a kerosene lamp. We would go up-stairs using all 4 limbs, hands on the step above and feet on those below till we reached the top which had no landing to speak of, just turn and you were in the first upstairs room, there was a drop down door that we had to lower once we were up there to keep the heat in for the downstairs, In the second room were two beds, one large for my sisters, and one small for me. That room had a lover that could be opened to allow heat from the coal space heater in the living room where my folks slept in winter to stay warm. The upstairs had no finish on the walls or ceiling, in the winter the shingle nails on the roof would have heavy frost on them, and when we woke up it was common to see your breath in the morning light that came from the one window that faced the East. It was a good life though, we all grew up to be successful, and all of us were very creative, you see you had to be because there were no televisions, phones just a battery pack radio that was high enough that we could not reach it to turn it on without a stool to stand on (batteries were expensive in the 50's)
I had a project like this but in the end i used a commom led strip, cut it in the minor lenght (3 LEDS) per step, fixed it in the handrail facing downward and used a PIR sensor to turn on the hole stair case. Also its integrated in Homeassistant so it can serve as indirect light for the living room. It's not that fancy indeed, but helps a lot
I love it, amazing project. No matter if it was a fail. Thank you for show us that sometimes something could be wrong. I enjoyed a lot with the concept, process and the creation. My wife also sit next to me often and say to me: Do it but don't broke it 😅 I'm looking forward for the V2 and probably you should consider to sell it! Could you consider to use a white cover for the Ledstrips and a small transparent section for the sensors. Great job!! 👍
You could use your clear covers and add defusion to them and leave the area in front of the sensor clear so they still work as intended. Projects like this rearly work right off so it's nice to see a realistic expectation here where it doesn't work right the first time. I like your solution for mounting the light strips and not attaching to the staircase itself you even got a good colour match, well done.
Great video. It shows the trials and tribulations. I was hoping for the part2 fixed it video. However i thin in think the connectors and other ideas on the comments are great and would like to see the part 2 integrate these ideas. I am intrigued by one commenters drill a hole in the diffusers, as it sounds like it would look horrible but might just work.
Since the PCB is visible through the transparent cover of the profiles, you could consider ordering them with white soldermask finish. I think it would improve the look drastically making it more "clean" - the green is quite an *interesting* contrast to the wood in my opinion... :)
I think you should try to explain to us how the daisy chaining mechanism is supposed to be working. And that would expose the problem very quickly. I visualized how inputs and outputs are interconnected between multiple boards on paper. And it seems that each board's output gets connected with two adjacent boards' inputs, but after that, also every second (one skipped between) board's input to the left and right gets the same output signal. So it gets a bit confusing then, thinking of what the firmware should be doing...
I have that same tiny hotplate. I cut a couple of blocks out of wood the same height as the hotplate to help support larger boards. It's a lot safer to use!
100% need the next iteration of these and update video! Been wanting to something like this for a long time. I did a much "older" variant using lasers and LDRs on each step as well as some ultrasonic stuff -- this is a much nicer solution once the bugs get ironed out
I have done something similar. Use a radar sensor (the cheap microwave I think frequency ones) and you can route a hole in the wood and mount it from the backside so you don't see it, they work through wood. Have one at the top of the stairs, one at the bottom. Build one control board to manage those sensors, and to turn the LEDs on and off. Run wires to the LED locations, and this can all be done on the backside of the wood so all you'll have on the front of your nice wood strip is the hole with the LEDs and you can add disfussion covers easily. Code it to turn the LEDs on in ascending or descending order (depending which sensor triggers) over 1-2 seconds, using PWM, and auto-shutting off in the reverse order after 20 seconds or so.
I like honest content creators that admit their mistakes 👍🏻 I like the idea with a sensor for each step. Ideally it should light up the next step as well, making it more complicated 😉
Really nice project! I gotta be honest, kinda felt good to see others having unexpected noise problems ruining their projects ^^' You definitely have to make a video about the solution (whenever you get back to this). Can't imagine to work involved in make these videos, but it's really nice to see the development and debugging process done by others. Great video and good job!💪
I think you should use higher voltage such as 12 volt with an optocoupler as low voltage is easily get affected by noise, and also use a 555 timer ic for PWM and time delay which can be triggered by a normal IR sensor. No need for a attiny. But all and all It was a very nice video for me because it gave me a chance to think.
I honestly don't consider this project a failure. The majority of the staircase seems to work passably well, and the lights that are stuck on, are at the top of the stairs providing you an unintentional safety bonus of always knowing where the first step down is. Sure, it's not by design, but I'd be happy with this.
No idea if it is related to the current problem, but I believe you drive too much current through the VCNL4200's IR LED: R2 is 2.7Ω (the example value in the datasheet) - but in combination with 5V supply and the LED's forward voltage (Fig. 10 in the datasheet), you would land close to 1A - the poor LP2985 is only rated at 150 mA, which might run it into overcurrent protection.
Such a neat project! I like very much the idea of an automated night light for the stairs. And your girlfriend was right to push for a solution which blends with the existing furniture: you did a very good job with the wooden housing. I haven't looked at the schematic yet so I won't comment on the troubles with getting the design to do its job properly. I'd like instead to make your life even harden 😆By chance I'm also looking to make a light helping me to find my way if I was to walk around the house at night and I'm thinking of using cyan (monochromatic) LEDs instead of white LEDs. The scientific reason is that the rods in the retina are the elements with the highest sensitivity to light and, even if they do not provide the perception of colours, they allow to see shapes with minimum ambient brightness. The peak sensitivity of the rods is around 500nm, which is a cyan colour. I reckon that, with cyan light, you should be able to get a good enough perception of the stairs while using significant less power than standard 'white' LEDs. Cree XLamp XE-G are available in cyan but you should be able to find cheaper alternatives.
Love the overengineeredness! If i would make this however id keep the simple stuff simple as the hard stuff is hard enough. Have you considered a single microcontrollwr for the whole staircase? Even an esp32 suffices. Add an ial lightstrip like a normal 28xx 12v one (12 for the large distance and voltage drop) and a seperate line with distance sensors. When all the sensors and lights are on 1 microcontroller, your code is immensly simplified. Just a maxvalue filter on the distance for the currently steppen on staircase and a minimum threshold. You can even normalise the noise by averaging out all the sensor input. This is the way
omg I understand this state of mind sooo well. I usually need to put the project somewhere so I can’t see it for a while. Everything should work but in reality it does not. Bad connection, noise, voltage drops, crosstalk
I really like your design choise, but i would have made a diffrent Approach by using 1 ARGB strip, some sensors and 1 microcontroller. This would really shrink down the boards complexity because you simply put the NEOpixles in series and just need some lines for the sensors, question is how far their power output can reach
If we don't design and try a project, how will we ever learn new things when they fail. Your project is 95% there, so take courage and try a different approach, from suggestions below. I was considering doing this for my kitchen with under counter lights. The idea is always to use the simplest solution with off the shelf parts. Just don't give up! I love your ideas and designs!🤞😎
I have some recommendations. Use a diffuser cover with a hole for the distance sensor. This will help to spread the light more evenly and avoid any unwanted reflection on the sensor itself. Instead of controlling individual LEDs that need to be programmed separately and are difficult to replace, consider using an addressable LED strip to control everything with a single microcontroller instead of 14 separate ones. This allows you to control each LED individually and define when to start and end a stair step, achieving similar functionality. You also get more flexibility and easier replacement. You can even change the color and brightness.
Thanks for sharing the failures and not only the successes. It's very educational and shows how making projects normally go. It's never pure success. One though I had during the video; I guess you can still use a diffused LED cover as long as you cut or drill "windows" where the sensors are.
Addressable / Zoning (with few staircase steps), based on dimensions e.g 1-5 steps ~ Zone 1, 6-10 ~ Zone 2 and so on, this will provide fault tolerance too, not all LED strips will go bad at any given point in time and thus some visibility will always be there to prevent a fall from staircase.
when the location is less important than the detection, you could add two sensors, one at the front of the PCB and one at the back, and add an AND or an OR gate for the signal (depending on the noise and/or functionality you want). That also solves one issue your current setup has: your lights switch on when you technically already stepped forward instead of "leading the way".
The IR sensors might break eachother if they power at the same time, you should probably do some multiplexing to make it cycle through the sensors (or at least not power the ones directly besides them all the time
I love your idea and execution... Was thinking about a project like this before but sadly I'm not smart enough to get it happening like you... Respect I appreciate each and every of your videos for the knowledgeable content... Weiter so...
Have you tried using a clock pulse which each module passes to the next and only enable each source and read each sensor one at a time. That should eliminate any possibly of reflections from the multiple ir sources interferring with one another.
Now that I've seen your results, I'd probably add communications between adjacent strips. Then one board could tip off the neighboring board to go into low light mode for a bit, or enable a timed cascading On/Off sequence for a more appealing presentation and integrated design. I'm eager to see the final design!
The comments/feedback is crazy!! Thank you all for your awesome ideas, suggestions, tips, tricks and whatnot. Really awesome to hear so many advices, opinions. I think part 2 of this project will be a "community" video in which I will partly test your ideas. Will be lots of fun. But it will certainly take a while until I get to that. So stay tuned ;-)
I don't understand why you didn't mount the lights under each step and put pressure sensors in the floor at the top and bottom... it's what I did at least.
Can't wait for the video. Wanted something like this on my stairs. Maybe ad the possebility to add this to Home Assistant.
@@philosoaperit would indeed be the easiest, but that would probably add a bunch of wiring that you can't really hide unless you start drilling and/or creating some slots.
@greatscottlab shared your video with our guys at Vishay. Hope they get in touch with you soon 😉.
Put a wood texture on the silkscreen so the PCBs blend in
I appreciate more the "I failed" videos than the "here how do to X perfectly". This is the best way to learn something and understand a project.
Specially since a considerable part of those end up being debunked as just not showing the tons of fixes behind the scenes, or downright faked to work.
Yeah it really shows how to do something and how not to do something at the same time
The truth about development. Sometimes, it just goes wrong. Thanks for sharing.
The reason more channels don't show all their failed attempts, is probably mostly about to saving time.
As we know - it takes quite a bit of luck for a project to work right away. Troubleshoting and possibly redesigning a few times is usually a part of designing something
- which often takes quite a bit of time on it's own. Now if making video documenting each step, redraw scematics to show of every change then edit all those video shorts, the project may take "forever" to get done, as more time will often be spent making the video, than on the project it self.
It's just so much easier to just wait with the filmning and editing, until everything is already finished and tested
- then make a detailed video how it works with scematics and how to build.
But yes, it can still be of interest those who take their time to even show the failed attempts and for those new to electronics, it can be very useful
it's a good way to get feedback on a complicated projects
I found where you have the problem!!!! I also double checked with a electronics technician that has 50+ years in component level troubleshooting and high frequency circuit design who just happens to be my father that my suspicions where correct. He was able to give a solution and explain why it was happening along with why you were getting that specific frequency.
Your driver circuit for the LED needs a second filter on the other side of the coil (U6) but before the diode (D3). In the current configuration, with the PWM being fed into there, you are pumping a RLC circuit in a single direction that has no where to release its energy other than ground and the power monitoring pin of the micro-controller (pin PA6 of part U3). Since it is going though a series of diodes, it is reflecting off of them and this is causing a doubling of the frequency. If you run a RLC calculation f = 1 / [2π × √(L × C)], you get 7.341 kHz for with the ideal component values and 14.682 kHz for the doubled, which is within 95% of the ideal component values, so accounting for the variance in the parts and the sub-harmonics we are seeing on the oscilloscope, this is pretty good proof that the hypothesis is correct.
To test it further, removing a single unit for testing would be advisable and then replacing filter capacitor C10 with a different value or adding one in parallel to change the value and then checking with an oscilloscope might be a possible way to check for it. It is also possible that the oscillating circuit is internal to the LED driver IC, so adding this cap may do nothing, but adding the filter at the location that I specify as the solution is going to still work as that is the correct filter location in the circuit.
You are going to need to put rejection filters between U6 and D3 that only pass DC and the fundamental frequency for your PWM signal. You could also get away with a low pass filter if the fundamental frequency for the PWM is low enough. I would suggest changing the PWM frequency to a lower value so that you can just use the low pass filter as high frequency noise is easiest to filter out. The datasheet for the micro-controller shows how to do this. As long as the resulting frequency is at least 10% below 7 kHz it should get rid of the noise. Assuming you are on the default settings for it, you should be well below that, but double check.
Now as to the why on why this was causing so many problems with the micro-controller. The default clock speed of the micro controller might be set to 16 kHz (+/- 3% over voltage range and +/- 2% over temp. range) by default, so, if you have a signal on the other end of the PWM output pin that is close to that and really noisy while being unstable, like you have, and that pin isn't optically isolated (which this micro-controller doesn't have optical isolation on its I/O pins and problems like this are why you want optically isolated I/O pins) the interference can be feeding back through the circuit and causing problems with the PWM circuit. 97% of 16 kHz is 15.52 kHz, which is close enough for some signal coupling, so it can feed back into the circuit and cause the clock for the PWM to start having errors that the processor will have to correct, which will cause all sorts of strange behavior.
I would change the internal clock that the PWM is using to the 20 kHz mode that the micro-controller has the option of using to just completely take it out of using a similar frequency. Make sure that the fundamental frequency that gets produced by the PWM still stays below the 7 kHz range using the equations given in the datasheet for how resolution and clock selection and clock type result in the output PWM signal's fundamental frequency.
Just putting the filter in will probably fix most of the noise, but lowest noise possible is the best thing to do when dealing with micro-controllers. I would suggest in future only using micro-controllers with optically isolated outputs and always make sure that if you have a cap and coil in series in an oscillating circuit with diodes that you have a filter for both directions that the coil can discharge unless you are trying to make it oscillate or build a higher voltage.
U1 is the LED driver at 7:30. The circuit he used is exactly the same as Diode's reference design, it is just drawn a bit weird. The chip itself is a bit weird for using high-side sensing instead of low-side. Aside from that, it is a completely ordinary buck regulator. The only thing "missing" is an optional filter capacitor across the LEDs at the regulator, which may help with EMI when the LED current loop is taking a ~35cm trip around the board.
@@teardowndan5364 I know it is buck converter and it is going to have a ring to it there unless you add a filter where I said to put it, they all do and that is the frequency of that specific circuit's oscillation. The problem he is getting is that the frequency it is ringing at is really close to the clock source the PWM circuit is using in the micro-controller. This is a problem because the micro controller doesn't have optically isolated I/O pins, so any high frequency signal that gets on one of those pins that is close to one of the frequencies the controller IC uses, it will propagate into it and start causing errors intermittently.
He might be able to get away with just changing the clock value in the controller from 16 kHz to 20 kHz. If not, he needs to filter off that noise.
A buck converter circuit is noisy. Connecting it to a digital circuit or a circuit with active components can result in weird behaviors since you are going to get noise from the buck converter that is in the kHz to MHz range, both of which are in the RF range where they start treating everything as active components, even the case of the circuit, so when it gets into an IC, things get weird. I would use a different power source for driving the LEDs in this application next time or isolate the power supply from the micro controller, like with optical isolation.
How does someone get this level of understanding
@coolmonkey619 2 year degree at a technical college will do it. A BS or BA in electrical engineering will also cover it. You are probably going to need a 3.0 or higher GPA or at least paying attention to the topics of power supply supplies, digital circuits, and high-frequency circuits. Just for this problem, having a basic understanding of IC internal design and clock generating is also needed for this as well. Then you also need to understand micro controllers along with microprocessor error correction to see why the problem was so weird.
I only confirmed my suspension about the problem with my father, who is a retired microwave telecom tech and designer because I could find the multiplier in the circuit that was giving the 15 kHz, but that is mainly because I would never have ran across this problem since my instructors warned me about the pitfalls of noisy power supplies and digital circuits along with micro-controllers needing the optical isolation or you can risk noise backfeeding into the I/Os or a transient coming in and frying the micro-controller.
@@KnightsWithoutATable If Diodes doesn't include any additional filtering, I am pretty sure it is because its engineers who work on this stuff full-time have done every analysis prescribed by best practices and have concluded that it is perfectly fine as-is for the IC's intended application and following applicable layout guidelines, which usually includes keeping all high-frequency stuff tightly packed, which it isn't when you have two LEDs in series spaced ~15cm apart and the traces in-between acting as an antenna.
Just had a look at his PCB layout. The LED trace routing is an EMI disaster. The current return trace needs to be parallel with the source trace like a differential pair, not routed along opposite board edges! And those power traces are also running parallel to the data traces on the other board layer. Maximum EMI.
6:50 you can use a diffuser cover and drill tiny (1mm diameter should suffice) holes right in front of the IR sensor.
I can certainly try to do that when I get back to the project.
I was thinking the same while watching the video!😄
@@greatscottlab a tube of acrylic may help with channeling the emitting side of the diode, which can then be shielded with heatshrink. A 3D printed bracket to hold this in place sounds perfect. 🙂Perhaps the V2 PCB's could have some holes in them to allow for locating and/or installing these brackets or features, if only for those who need it getting the inspiration.
Or just use a small section of the clear one where the sensor is, while the rest can be diffused.
Another solution is to use the clear cover and scuff up the rest with sandpaper except from where the sensor is.
I did this using an addressable strip, arduino and 2 pir sensors for top and bottom, it's been working great for around 7 years now
Maybe using addressable LEDs would be easier.....
Do the pir sensors also give a distamce reading or just digital signal?
@@rizen3467He shows them giving distance readings.
@@rizen3467 I do not think you need the distance, but only the signal true/false
This could also work with a mmWave radar presence sensor which measures distance.
To be honest this was one of the most eye-opening of your videos to me. Seeing such a theoretically simple and trivial project experience issues due to noise and other things.
If you redesign the boards, it might be easier to use connectors to slide them together, soldering them all together will have to many failure points and you cant take it apart to diag and repair.
I like that. I should really do that.
@@greatscottlab I was thinking a surface mount, right angle, pin header like M22-5330405 (found on digikey) for low profile easy connections. I’m sure you can find something like it cheaper and quicker on JLCPCB, but their connector page wouldn’t load for me.
@greatscottlab maybe with pogo pins
@@greatscottlab also make them so that you can disconnect them without sliding out everything, maybe even make them 2mm smaller and glue them into place so that you can take them out easily
Honestly I think that idea could be commercialized pretty easily. If they are snap together all-in-one units that a do-it-yourselfer could easily accomplish... that would be a great selling product.
It's legit more enjoyable to watch the fail videos than the success videos. The fails are where you REALLY learn something new.
Perhaps use a white Pcb next time? Might blend in a bit more. Canny help debug unfortunately.
how did u comment on 3-4-24 , 4 days ago.when video is out one hr ago
@@dhansukhjaladi6155 Paetron/UA-cam members get early access to (unlisted) videos.
We found a Time Traveler!!!
@@dhansukhjaladi6155 - Patreon supporters get early access.
@@dhansukhjaladi6155 probably he is a patreon supporter and can access the videos earlier
@greatscottlab LED Lighting Electronics Engineer here. I reviewed your project files and a few things:
1) put 0.1uF and 10uF cap on the input and output of your LED switcher. You actually need a high freq cap and lower freq cap to cover the freq range for input and output ripple
2) I like the 4-layer idea, but do 2 internal layers of ground, and only route on top and bottom. Also, make sure to sink a ground via right next to every signal line via (this will help the signal keep good ground reference and force the inductive coupling on the internal layers to follow a set path. Try to reduce the number of vias per net as much as possible (don't want added inductance)
3) Make sure to look at the recommended switcher layouts and make your switching nets small, and DO NOT let them go onto other layers (don't want to have inductive coupling between layers). Also, try and get ground between traces so you don't get cross talk. At the lengths of your PCBs, I'd expect you could get Volts worth of cross talk, even at sub 100MHz freq.
4) I'd add a common mode choke to the input of every PCB and a Pi-Filter too. It may be overkill, but for a few extra bucks you grantee each board isn't getting noise on the input. Make sure to route this all on the same layer as the connection between boards (so top layer for you). The shear length of the boards all ganged together is working against you and stray fields from surrounding power lines and appliances/electronics could get onto the boards and cause some weird behavior. Better to go all out and find you you don't need it then to find out you do need it haha.
I highly recommend "philslab" on youtube as has some great videos giving best practices. The whole FEDEVEL group is very helpful for PCB design for EMI / EMC. Wish you the best of luck man! I love your videos and love the idea ;) Keep it up man!
Thank you for sharing this golden knowledge
The design of the data lines won't work as indended as described at 5:12, there should be one diode for each OUT pad, not one for both. In your current design, every other board is commoned together via the OUT-Line of the board in between:
Board A In2↔Board B OUT1/OUT2 ↔Board C IN1/IN2 ↔Board D OUT1/OUT2↔Board E IN1/IN2...
Most likely that's why all the boards were lit in most of your initial trouble shooting. The boards at the top of the stair (which later you found missbehaving) pulled all the other inputs low, until you introduced smaller pull-ups until the voltage drop was enougth to be registered as low.
I can’t quite get a good picture of the PCB design, but it looks like this would be a pretty easy modification to the existing boards. Right?
@@jdl3408 could be as simple as adding a diode where the boards connect together.
I noticed that too. His outputs are connecting to outputs and his inputs are connecting to inputs in his drawing. If it's the same on the actual PCB, then that would explain a lot
@@conorstewart2214 Oh that's an nice and easy way to fix that :D Great idea! Just bridge D1 and use diodes to bridge the boards together 👍
I was trying to understand how he was gonna make that work in my head when he said that. Maybe a bunch of diodes or something
When I made some under cabinet led tape lights integrate with doors and mains power about five years ago, I had a similar story. A "weekend project" spiraled into about 8 work days of effort and required a one year break for "finishing touches". I could not be happier with the results, even thought it needs another minor touch up. Your project is so much more ambitious and I cant wait to see how it turns out!
i don't know why your impression of your girlfriend was so funny to me
Haha she also liked it ;-)
True
Impression?
me too 😂
lol, it was quite funny. just like my wife, 'you are not going to put a solar light up here'. Our porch needed a motion light, and she insisted it not be visible, so I had to hide it all.
I appreciate you sharing this even though it didn’t go to plan. Being able to see how other people investigate and solve faults is incredibly useful 😊
Nice to have pictures of yourself everywhere on the walls. 😂
Another reason why I made the LED lights. So that I could see those pictures better ;-)
True
Next project idea. Have the eyes on the pictures follow you.
I had to check twice XD
Aren't those just for the video?
Thanks for sharing. Why didn't you use an addressable led stripe (e.g WS2812B) plus the sensors to know where is the person and only one microcontroller governing all of them?
You could use the WS2811 IC, it's the one that is in the neopixel, just replace the RGB LEDs with white LEDs, like that you can control 3 white LEDs with one data line. That way removes the need to have a constant-current source (or sink) to drive the LEDs with a PWM (or any switching power regulation), and then also removes the high frequency noise that could be induced in the circuit.
Hmmmm not a bad idea. I mean the WS2811 is an IC/LED that have been around for a while and it works just fine. I will consider it.
@@greatscottlab I'd just put in the WS2812/13 LEDs that have the IC built in, saves component cost and you can build in a april fools version where the stairs turns itself into a disco just 'because you can' :P
Or use a SK6812 addressable RGB + warm white strip. Then you can easily control the white LEDs and also have the optional RGB disco mode :)
@3zuli @someguy4915 These options would also work, it will also allow to have red night light but I was supposing that @greatscottlab didn't want to have/use RGB LEDs and wanted better white LEDs.
@@someguy4915 disco stairs got my vote !
I came accross this brilliant video a couple of weeks ago and absolutely loved it, including the issues and how you try to deal with them. All of a sudden, I don't feel alone anymore :). I found the idea very good, so I had to try it and sourced a few components and knoked up a few boards on the micro cnc and wired everything > I modified ever so slightly the schematic and the code to address some logic issue with the pin In and Out. On one board everything works, but as soon as you connect several boards they start firing up randomly. Like you I spent a bit of time trying to figure out what happened. My conclusion was that it was nothing to do with the noise on the in/out line. In fact the issue is the variance in the response from the VCNL4200 sensor from one unit to the next and also within the same unit!. So I finally got it to work by measuring a "reference threshold" in the setup of the code (so I might have different value for each sensor) and also by taking the average of 11 samples for each reading of the proxy sensor. That completely fixed my issue! (I think ;) ) If you are interrested in the code or schematic I can of course share it.
Thanks again for your great work!
it's actually really nice that you share the files and a list of the used components for the projects you do, kodus:)
Frugal Engineer : This can be done with two proximity sensors, the 1st at the beginning of the staircase and the 2nd at the end. Keep the entire LED strip on until you pass the ladder.
Use reliable MCU and LED drivers.
As per my understanding, you don't want to manually turn on/off the house lights, and you don't want big bulbs to be lit
that's how i do it. I use neopixels though, just for a sleek effect to have the leds roll on, out in front of me. GF loves it
But he wants to turn on the LED in front of him before do the step
@@albertoandrescuevashiguera4304 We understand what he wants and that would make for a rather cool effect but seriously there's no need to overcomplicate lights in this way, especially when they're only going to be active for about a minute once or twice per night, I mean it's just for lighting stairs just leave them on all night at the lowest visible brightness...
@@albertoandrescuevashiguera4304 Doesn't make any difference, it serves the purpose, that's the only thing that should matter logically.
Keep the LEDs on until you're done, not just the steps, but the entire staircase.
There is a concept humans have they call "aesthetics". A little weird to us, but it mainly means they like things just from their look and feel. More than that: This can differ in every one of them!
To us it has a logical benefit, though: It covers the case where someone turns around on the stairs or two people go. Which would be no issue if both sides just trigger a timer, though.
I was going to make animated lights on my staircase but decided a simple "all on", when a person is detected, was safer. I used a multivibrator circuit to turn on the lights for 30 seconds, and re-trigger whenever motion is detected. Fancy lighting effects look cool, but are distracting and dangerous IMHO. I love your method for mounting the LEDs. I chose to do the massive wiring to each LED approach, lol.
Yea that's the I way. A local shop to me installed one of those sequencial stairs that was sequential in both the steps and the sides (not shure if it makes sense), and I found it super distracting going up those stairs until I sort of memorised them and got to go up without caring about the light.
I love that you show what didn't work. I'm still at the beginning and my first thought would be to illuminate the whole staircase dimly with a few presence detectors (including beginning & end) or use buttons for simplicity and use a timer to turn it off after a suitable amount of time.
Illuminating each few steps individually seems like an anti-feature feature because we literally lookahead to plan our steps in advance.
Great attempt for a sleek solution, good luck for v2 when you'll get back to the project 🤞🏻
Fingers crossed! Thanks :-)
@@greatscottlab omg the legend himself! Love your channel, it was a big inspiration for the last 8 years with my studies in electronics. Thank you 🫶🏻
This reminds me of a project I built back when I first started tinkering with electronics: A motion sensor based light controller with a PIR motion sensor. It worked beautifully most of the time, but whenever someone would flip on the light in the next room over, it would trigger the motion sensor resulting in the lights coming on in the middle of the night. I suspect I had similar issues with the input voltage fluctuating too much and confusing the sensor.
Thank you for the great video, keep up the good work and don't give up!
Maybe the IR distace sensors are interfering with each other. Try to place a narrow tube infront of the sensor to narrow it's field of view.
maybe if he tried it with light diffusion material with narrow holes just for the sensor's diodes, I think its small enough to disappear when looking from a distance.
That's what I was thinking too - however a tube may not solve the issue as there may still be light reflected from other surfaces / feet.
It might be an option, since you have comms between the boards, to activate the sensors one at a time so it effectively scans the stairs. Then each sensor will only receive it's own light.
No. I checked most sensors while all were operating. They do their job just fine.
The IR led has only +-25 degree cone and the sensor drops to 50% at +-30 degrees, it probably isn't a problem
Custom cut pieces of clear acrylic to be placed atop the sensor. The rest can be diffused.
THANK YOU SO MUCH for sharing your entire process - it is so refreshing to see setbacks and someone holding their hands up - too many people think experts know everything -crazily - this is the EXACT thing ive been thinking about doing - I'm so glad its not just me that gets stuck and frustrated so much you have to just walk away and come back with a fresh mind later. Thank you for sharing this - I would be VERY interested in the solution you come to when you do.
You have noise on the Input Pin (PA7)
Add a 100nF capacitor between PA7 and GND.
Place the capacitor close to the ATtiny402.
When using long wires, in your case long traces, you made a Antenna.
All input pins should have Capacitors on them, but the higher the capacitance, the lower the switching speed, so you'll have a lower transmission rate
VL53L1x is a Lidar sensor from ST. it worked well and came cheap at cost. Program the sensor to turn LEDs "ON" position for the next two LEDs. I learned many things from you.
Modifying things as soon as we get them is how we operate.
Haha nice
It's immensely relieving for me to see that I'm not the only one who doesn't get it right immediately. Thank you GreatScott! And: would love to hear how you'll fix this (and I know you will!)
Oh man I LOVE the "we just got this staircase, you will not damage it in any way". Any tech man needs a woman like this to keep things sane. My girl does the same. You girl is a keeper :)
0:51 We definitely also need the baby's opinion about the lighting
On a similar project that I worked on; we needed to send a signal across interconnected PCBs without limiting the number of boards that could be connected. We used a buffer IC to refresh the signal from board to board so no significant voltage would be lost if the user wanted to connect several boards together.
Great that you’re also sharing failures! Do you really think the noise on the VCC is causing this and not a coding issue?
Well, I spent so much time on this project that I kind of had to make it into a video. And no, coding is not the problem because everything worked fine when testing with less units. I think EMC is the big problem here.
@@greatscottlab Consider the CN5711 led driver, it doesn't require an inductor.
A bunch of sensors can mess with each other. I went with radar (Doppler GHz) at top and bottom, they are far enough to not see each other. Then you can turn on all the LEDs in sequence (away from motion) and control them all from nice microcontroller. Giving you tad more time to move past them. Then shut them down again in sequence. And those radar sensors are so awesome!! Oh, addressable LED’s could share power and data. And I agree, we love learning along side you. My projects go the same way! ;)
Can you maybe do a video about "Choosing the right microcontroller for your project"? Or generally explain how you search for a suitable microcontroller
It pretty much breaks down to the following:
1. Do you already own the expensive programmer for a particular brand of micro controller. (start looking here and use one unless there are litterally none that meet the other following requirements)
2. Consider the number of general I/O pins you need and if you need any special features like a DAC or audio peripherals (essentially anything you want built into the microcontroller and would rather not have it on a seperate IC)
3. Is the microcontroller fast enough / has enough flash memory for your program. If you're using Arduino consider a micro controller with at least 8KB of Flash so you have a good amount of room for your actual program. Also make sure it's fast enough to do what you need it to do if you're using an ISR for example to do something.
Those are pretty much the basics for choosing a micro controller for a project.
I’ve learnt 1000 times more from projects that don’t work as expected than ones that do.
I love the concept it looks fantastic. 👍🏻
My solution: Up and down is one HLK-LD2410, both connected to ESP8266. The bottom one has one pin connected to LED strip with WS2812 LEDs on the whole path of the stairs. Once motion is detected near the bottom one, the LEDs will light up from bottom to top. Once the motion is detected on the top one, it sends the signal to the bottom one and the stairs will light from top to bottom in "usual" walking pace. Works great, keeps the light on for next 5 seconds, to allow kids to, for example, find the entrance to bathroom, or to the next staircase, then the lights "go out" in the same way the came in. Works great, the whole solution costed less than $30, if I do not include the aluminum LED channels - those were the most expensive part of the project in the end :)
And as this is radar, I have no problem with transparency of the plastic ;)
I think this is a much better and simpler solution than the one presented.
It took me three weeks four different tries with the programing (worse than you in that area). Finally went to a friend about the code he showed me that using a state machine was the best case and it mostly works. The issues on the board like noise and signal integrity were mostly the board layout and lack of proper filtering. I have built this in two different places, and for the most part they are still working. Had an LED go out on one about a year back. Mine are made to react to the step before being on or off state. Also had to angle the motion sensor up at a thirty five degree angle to keep the cats from playing with the lights.
Peace
Is the prox sensor seeing the stair itself and activating? I noticed in the video it appeared that your knee was activating the stair above.
would be good to know whether the code responds to *changes* in the distance above just the baseline.
I feel your pain, my friend… we all have those frustrating project experiences. Thank you, for sharing yours. I’ll look at the files and think about this and send any thoughts later. Great video, as always! 👍😊👍
An addressable led strip with a ESP32 with WLED and two IR sensors (one on top of the staircase and one at the bottom) could do the trick relatively easy (even change the effect/brightness at certain times of day). Maybe even coupled with home assistent to intergrade in the smart home.
this is my setup and the sensors also turn off the led power supply when not illuminated with the animated staircase user mod
That would be the easy way. But it's like 100x cooler to only lit up the individual stairs currently being used.
Had very similar idea back in 2021 while building my stairs. Wanted to do all just using analog discrete parts. Never actually got to it. Good luck with your project and thanks a lot for the kick I probably needed to get back to this project.
Wouldn't the ground and/or VCC planes act as a rather large antenna like this?
Kind of. That is why I will probably have to add some filter at every input/output.
@@greatscottlab perhaps it might help to reduce the size of them, and for the ground plane to only really extend under the attiny and the LED controller IC.
It might also help to run VCC and ground over an external (twisted?) wire pair, but that would somewhat defeat the purpose.
If not already done, it can be beneficial to connect the aluminum profile to GND and/or protective earth. This can reduce the "noise" fields by giving those a decent path to "conduct" to.
I LOVE THIS PROJECT!!! I know you feel frustrated by it but you definitely when through all the troubles and troubleshooting problems someone would have gone through when developing a small project and i love it!!!
You simply should enable only 1 distance sensor at a time, not all at once. Distance sensors are interfering with each other when they are simultaneously firing . Also most probably the distance sensors are the ones that create the noise.
I checked most sensors though while all were operating. And they did their job just fine.
@@greatscottlabBut you didn't on the staircase. The stairs itself are probably interfering that.
We would need to know how long the IR pulse is and how often he is doing a measurement to know how big of an effect this would have…
@@vlcekmlcek3393he did. the boards are the staircase for the rest of the time, and he probably brought the laptop to the stairs
But how do you activate only 1 at the time? To know if person is standing on the step you need for distance sensor to be turned on at all time and you have no idea from which direction up or down someone will go
Thanks for sharing your problems so others don't "fall" into the them. Engineering is all about iterating so no shame in prototyping. Can I suggest having LIN bus or another com line among all the sections so not only will they light up where you step but where you are going to step. The LIN bus would also help you debug so you only have to talk the primary chip to debug the entire strip.
Scott imitating his wife was gold.
I love the I tried it this way and it failed, and tried it another way and it failed over and over relentlessly. the break is going to help you piece together all those moments and you're probably going to discover the cause: whether it's some frequency, heavy pulldown, floating grounds etc. Kudos "Great Scott" for the endeavours.
Love the part where he tries his best to sound like his girlfriend.
Great project. I love the fact that you take us all through the design, build and problem solving and not just "look I build X and it's working". I can't wait to see how V2 gonna be.
Was this the first appearance of the angry girlfriend? 😂
Actually the third. She also played a role in my vacuum cleaner story ;-)
Face reveal when?
yeah he destroyed a vacuum. thats why she is angry
@@omerfidan892 😁
You should do a crossover with @stuffmadehere wife ! Most ironic wife on youtube.
That is such an excellent project! I see where you were headed with it, (and kudos for working as a carpenter for a bit- THAT can be quite frustrating if it's not something you do all the time!) I learned some things, and JLCPCB pricing info... I can't wait to get home so I can work on some original design boards to try them out! Don't feel bad, that try, fail, retry, walk away loop happens to all of us!
yeah I have the same problem with see through stairs. I had other ideas but seems we may move out potentially, so we'll see
6:50 just drill 2 small holes. makes it very directional and not false trigger
For the noise problem coming from the switching power supply, I suggest you to use shielded inductors. And maybe, you can also try to connect to ground the aluminium bar. It can act as a shield. I also suggest you to use some sort of connectors between the modules, instead of soldering them together, so if a module need to be replaced, you can do it easily.
Could the aluminum casing be causing shorts? At 9:01 you can see that there are some vias I think? Probably the back is just GND or something?
Please correct me on why not. I am not very experienced with practical things in the electronics world.
This is great, Scott!
As other comments mentioned, I would consider using addressable led strips, but also taking advantage of the different colors you can turn on. At night, the blue light is the one you should avoid, so you might turn on the leds on yellow color.
Geiles Projekt! An sowas hatte ich auch schon gedacht :D
Hi! I looked at the project files to see if I could help with something and I think there are some issues with the daisy chain. Since in1 and in2 are basically the same wire and so are out1 and out2, connecting out2-in1 and out1-in2 causes issues if you have four boards or more. Let's say we have Board A firing up, it will send a signal to Board B through out2_A - in1_B, which will be seen by Board C through in2_B-out1_C and then fed to Board D through out2_C-in1_D leading to it firing up as well. That is what we see at 11:42 where every two boards light up when only one is triggered.
It looks like there is another issue with the boards on the top of the staircase causing them to always be lit up, I don't know why for sure but because they seem to be able to lit up without always triggering the other boards down the staircase I would assume that the trigger doens't come from a wrong digitalWrite but rather a false positive digitalRead propably due to noise.
I hope you can end up making the project work because the idea looks nice!
Thanks, excellent content! Some issues with the signalling are already well covered in the other comments but as an alternative, how about a simple analog circuit for the "signalling the neighbours"?
You could have one common "sense" line, with a series resistor (eg. 1k), and another (eg. 1k) to the ground, in every PCB. The board (or boards) that detects movement would then pull the line up. This would create a voltage ladder circuit across all the other boards in the system. The "origin" board would have the sense signal at +3.3, next board seeing something less than half of that, and so on. I believe ATtiny can easily source/sink the required 5..10 mA from the output pins, and has a 10 bit ADC to measure the voltage (*). This would require only one pin and connection between the boards. Noise filtering, on/off delay and range (ie. how many adjacent boards to turn on) could then be tuned in the software.
(*) edit: for example two boards triggering, the circuit and voltages would be like tinyurl.com/27fdw7yt (circuitjs).
I did a similar project with a lightstrip and two movement sensors, one at the top and one at the bottom. This way you can program the lightstrip to light up gradually starting at the sensor which was activated. Looks pretty smooth. And quite easy to implement!
bro belive it or not but i just finished my new home heavy construction and today i put my pover cables inside of wall for stairs led lights. Come home for searching about it and first video was yours. Its not a first that you hellping me almost instantly. Thanks, love from Azerbaijan
I’m watching this with great interest, I’ve been planning a very similar project for a while now!
I love this project in particular. One thing that I could try if I was you is to try to optically isolate the sensors in a sort of rectangular tube, because it seems to me that the sensors are receiving bouncing IR from each one as you move into the stairs.
Happy debugging!
You are indeed making me feel my age. When I was young, from birth to age 12, we lived on what was called the "home place' an old house built by grandfather in 1910. While REA came through and put a high line pole in our yard, nobody bothered to run a wire to the house or for that matter wire the house for power. So it was, when we went to bed in the 2 rooms that were "upstairs" we climbed the steps which were painted white but have a black mat on each step so there was pretty much no light other then that small flickering lamp that mom had lite in the kitchen below, that being a kerosene lamp. We would go up-stairs using all 4 limbs, hands on the step above and feet on those below till we reached the top which had no landing to speak of, just turn and you were in the first upstairs room, there was a drop down door that we had to lower once we were up there to keep the heat in for the downstairs, In the second room were two beds, one large for my sisters, and one small for me. That room had a lover that could be opened to allow heat from the coal space heater in the living room where my folks slept in winter to stay warm. The upstairs had no finish on the walls or ceiling, in the winter the shingle nails on the roof would have heavy frost on them, and when we woke up it was common to see your breath in the morning light that came from the one window that faced the East. It was a good life though, we all grew up to be successful, and all of us were very creative, you see you had to be because there were no televisions, phones just a battery pack radio that was high enough that we could not reach it to turn it on without a stool to stand on (batteries were expensive in the 50's)
I like the way you never give up no matter how many times you fail to succeed your goal
I had a project like this but in the end i used a commom led strip, cut it in the minor lenght (3 LEDS) per step, fixed it in the handrail facing downward and used a PIR sensor to turn on the hole stair case.
Also its integrated in Homeassistant so it can serve as indirect light for the living room. It's not that fancy indeed, but helps a lot
I love it, amazing project. No matter if it was a fail.
Thank you for show us that sometimes something could be wrong.
I enjoyed a lot with the concept, process and the creation.
My wife also sit next to me often and say to me: Do it but don't broke it 😅
I'm looking forward for the V2 and probably you should consider to sell it!
Could you consider to use a white cover for the Ledstrips and a small transparent section for the sensors. Great job!! 👍
You could use your clear covers and add defusion to them and leave the area in front of the sensor clear so they still work as intended. Projects like this rearly work right off so it's nice to see a realistic expectation here where it doesn't work right the first time.
I like your solution for mounting the light strips and not attaching to the staircase itself you even got a good colour match, well done.
But IR has a hard time going trough any plastics, so a hole in it would work better in this regard.
Great video. It shows the trials and tribulations. I was hoping for the part2 fixed it video. However i thin in think the connectors and other ideas on the comments are great and would like to see the part 2 integrate these ideas. I am intrigued by one commenters drill a hole in the diffusers, as it sounds like it would look horrible but might just work.
What a great project. Well thought out and implemented (almost). I look forward to the next episode. As always, keep up the good work.
Since the PCB is visible through the transparent cover of the profiles, you could consider ordering them with white soldermask finish. I think it would improve the look drastically making it more "clean" - the green is quite an *interesting* contrast to the wood in my opinion... :)
I think you should try to explain to us how the daisy chaining mechanism is supposed to be working. And that would expose the problem very quickly. I visualized how inputs and outputs are interconnected between multiple boards on paper. And it seems that each board's output gets connected with two adjacent boards' inputs, but after that, also every second (one skipped between) board's input to the left and right gets the same output signal. So it gets a bit confusing then, thinking of what the firmware should be doing...
I have that same tiny hotplate. I cut a couple of blocks out of wood the same height as the hotplate to help support larger boards. It's a lot safer to use!
100% need the next iteration of these and update video! Been wanting to something like this for a long time. I did a much "older" variant using lasers and LDRs on each step as well as some ultrasonic stuff -- this is a much nicer solution once the bugs get ironed out
Finally the content im expecting from this channel. Great idea with good approach about ho to solve it. Not matter failed or not.
Please share more " I failed" videos. These help us so so much. Thank you.
I have done something similar. Use a radar sensor (the cheap microwave I think frequency ones) and you can route a hole in the wood and mount it from the backside so you don't see it, they work through wood. Have one at the top of the stairs, one at the bottom. Build one control board to manage those sensors, and to turn the LEDs on and off. Run wires to the LED locations, and this can all be done on the backside of the wood so all you'll have on the front of your nice wood strip is the hole with the LEDs and you can add disfussion covers easily. Code it to turn the LEDs on in ascending or descending order (depending which sensor triggers) over 1-2 seconds, using PWM, and auto-shutting off in the reverse order after 20 seconds or so.
Great project! Thanks for honestly sharing that not everything worked as expected!! Super helpful for the listeners to learn as well!
Love the project! Me and my brother has been thinking about a similar solution for his stairs!
Not sure I can help too much but really nice work! 🎉
Great project! And nice to see you working on a solution! I hope you will get it working!
Great idea, seems like most electronics projects i take on, always hidden problems, would love to play with your design, singularly they work well.
Go for it!
I like honest content creators that admit their mistakes 👍🏻
I like the idea with a sensor for each step. Ideally it should light up the next step as well, making it more complicated 😉
Really nice project!
I gotta be honest, kinda felt good to see others having unexpected noise problems ruining their projects ^^'
You definitely have to make a video about the solution (whenever you get back to this).
Can't imagine to work involved in make these videos, but it's really nice to see the development and debugging process done by others.
Great video and good job!💪
I think you should use higher voltage such as 12 volt with an optocoupler as low voltage is easily get affected by noise, and also use a 555 timer ic for PWM and time delay which can be triggered by a normal IR sensor. No need for a attiny.
But all and all It was a very nice video for me because it gave me a chance to think.
I honestly don't consider this project a failure. The majority of the staircase seems to work passably well, and the lights that are stuck on, are at the top of the stairs providing you an unintentional safety bonus of always knowing where the first step down is. Sure, it's not by design, but I'd be happy with this.
No idea if it is related to the current problem, but I believe you drive too much current through the VCNL4200's IR LED: R2 is 2.7Ω (the example value in the datasheet) - but in combination with 5V supply and the LED's forward voltage (Fig. 10 in the datasheet), you would land close to 1A - the poor LP2985 is only rated at 150 mA, which might run it into overcurrent protection.
Such a neat project!
I like very much the idea of an automated night light for the stairs. And your girlfriend was right to push for a solution which blends with the existing furniture: you did a very good job with the wooden housing.
I haven't looked at the schematic yet so I won't comment on the troubles with getting the design to do its job properly.
I'd like instead to make your life even harden 😆By chance I'm also looking to make a light helping me to find my way if I was to walk around the house at night and I'm thinking of using cyan (monochromatic) LEDs instead of white LEDs. The scientific reason is that the rods in the retina are the elements with the highest sensitivity to light and, even if they do not provide the perception of colours, they allow to see shapes with minimum ambient brightness. The peak sensitivity of the rods is around 500nm, which is a cyan colour. I reckon that, with cyan light, you should be able to get a good enough perception of the stairs while using significant less power than standard 'white' LEDs. Cree XLamp XE-G are available in cyan but you should be able to find cheaper alternatives.
Love the overengineeredness! If i would make this however id keep the simple stuff simple as the hard stuff is hard enough. Have you considered a single microcontrollwr for the whole staircase? Even an esp32 suffices. Add an ial lightstrip like a normal 28xx 12v one (12 for the large distance and voltage drop) and a seperate line with distance sensors. When all the sensors and lights are on 1 microcontroller, your code is immensly simplified. Just a maxvalue filter on the distance for the currently steppen on staircase and a minimum threshold. You can even normalise the noise by averaging out all the sensor input. This is the way
omg I understand this state of mind sooo well. I usually need to put the project somewhere so I can’t see it for a while. Everything should work but in reality it does not. Bad connection, noise, voltage drops, crosstalk
I really like your design choise, but i would have made a diffrent Approach by using 1 ARGB strip, some sensors and 1 microcontroller. This would really shrink down the boards complexity because you simply put the NEOpixles in series and just need some lines for the sensors, question is how far their power output can reach
If we don't design and try a project, how will we ever learn new things when they fail. Your project is 95% there, so take courage and try a different approach, from suggestions below. I was considering doing this for my kitchen with under counter lights. The idea is always to use the simplest solution with off the shelf parts. Just don't give up! I love your ideas and designs!🤞😎
I have some recommendations.
Use a diffuser cover with a hole for the distance sensor. This will help to spread the light more evenly and avoid any unwanted reflection on the sensor itself.
Instead of controlling individual LEDs that need to be programmed separately and are difficult to replace, consider using an addressable LED strip to control everything with a single microcontroller instead of 14 separate ones. This allows you to control each LED individually and define when to start and end a stair step, achieving similar functionality. You also get more flexibility and easier replacement. You can even change the color and brightness.
Thanks for sharing the failures and not only the successes. It's very educational and shows how making projects normally go. It's never pure success.
One though I had during the video; I guess you can still use a diffused LED cover as long as you cut or drill "windows" where the sensors are.
Addressable / Zoning (with few staircase steps), based on dimensions e.g 1-5 steps ~ Zone 1, 6-10 ~ Zone 2 and so on, this will provide fault tolerance too, not all LED strips will go bad at any given point in time and thus some visibility will always be there to prevent a fall from staircase.
when the location is less important than the detection, you could add two sensors, one at the front of the PCB and one at the back, and add an AND or an OR gate for the signal (depending on the noise and/or functionality you want). That also solves one issue your current setup has: your lights switch on when you technically already stepped forward instead of "leading the way".
The IR sensors might break eachother if they power at the same time, you should probably do some multiplexing to make it cycle through the sensors (or at least not power the ones directly besides them all the time
I love your idea and execution... Was thinking about a project like this before but sadly I'm not smart enough to get it happening like you... Respect I appreciate each and every of your videos for the knowledgeable content... Weiter so...
"Täglich grüsst das Murmeltier"
Mit der wiederholenden "es funktioniert noch immer nicht" Szene fühle ich mich wie zu Hause.
Have you tried using a clock pulse which each module passes to the next and only enable each source and read each sensor one at a time. That should eliminate any possibly of reflections from the multiple ir sources interferring with one another.
Now that I've seen your results, I'd probably add communications between adjacent strips. Then one board could tip off the neighboring board to go into low light mode for a bit, or enable a timed cascading On/Off sequence for a more appealing presentation and integrated design. I'm eager to see the final design!