Hello Andreas, welcome back. I have a little tip for your power supply at 2:37 (Tenstar 230V). A strain relief should be attached for the 230V cable. I use a cable tie in such a case. I push the cable in a little further and tighten a cable tie. In this way I achieve that there is no pull on the soldering points. In Germany, strain relief is mandatory.
Power over Ethernet (POE) or the newer PODL are options for LAN connected devices. 10 Mbps at a 1000m for (Single Pair Ethernet) SPE-PODL. PODL is much simpler to implement than POE as the power supply current doesn't have to run through the magnetics.
Agreed (I made a video about POE). I could have added the use case for projects with wired Ethernet, you are right. Concerning PODL: Is this already widely adapted? I never heard of it
Great job with putting those usecases in order! :) And I share your love for HT7333! With small correction, that its dropout voltage is 150 mV - both in the datasheet and personally tested :). With battery going down to 3.45 V it keeps giving pure 3.3. Battery going down to 3.44 V - it goes down to 3.29 on the output, and so on - going down in the linear fashion, always 0.15 V below the battery voltage. Which is still great and more than enough for 3xAA batteries. And ESP32 still keeps working even with 3.0 V ;) (which means 3.15 V from 3xAA, which is when they are almost 100% empty :) ).
@@AndreasSpiess Oh my!! I was very sure about that 150 mV, but indeed the datasheet says 90... Is my memory soo bad? Noo! :) I must have remembered the value well from the time you showed it in episode 58 (small cell battery powering sleeping ESP8266) many years ago!! There you said and SHOWED on the datasheet the value 150. They must have changed the datasheet in those few years :). Plus my own tests always showed consistent 0.15 dropout.
I've been designing around single cell lipo batteries for about a year now as i've been developing my invention and i've found that they do wonderfully if the power consumption is managed correctly. Integrating a lipo charger in the form of an MCP73831 is extremely easy and it can charge the batteries I use very very quickly. I just throw in an AMS 3.3V LDO (the same vreg found on the devkit modules) to verify proper regulation. That aside, the video is fantastic as always
Something about the use of EEPROM. We had written a small library, with writes the information not allways at the same memory cells. If you do it right, the 10.000 cycles "problem" is gone. We had made a test - we wrote 1K blocks to an EEPROM about the size of 64k. The first data lost was around 2 Mio cycles :-) Detected with a simple CRC in the blocks. Something similar is done by the controllers of SD cards and USB Sticks.
I think we did at as filesystem. enough writes to certain block it swapped to next. I think all our blocks had info what file chain it belongs and what is write amount. so when we boot we scan eeprom block headers and create toc in ram. Edit: Need to check these FRAM chips. I think they also wear out when reading
Love it. The simplest version I know of is to zero everything, then only ever write in full eeprom write blocks. Scan to the first available detected block and write there. When full zero everything. using a smarter algorithm like yours on battery is probably wise to minimize cpu time scanning.
@@LimbaZero Please get Fujitsu Product Overview datasheet. Also UA-cam will Show you good Comparison. When write speed is a concern: also FRAM. At least in my projects. Greetings Henry...
I'd like to amplify comments about the benchmark Andreas has established with his videos. This particular one is a great in so many respects: It (quite properly) prioritizes a methodology for analyzing needs; It provides simple practical recipes for bears-of-little-analog-brain; It's a master class in video design, and elegant, cost-effective production, saluting many well-established golden rules, and avoiding gratuitous distraction. Andreas: welcome back. How do you crank out didactic masterpieces like this week after week? Maybe one day you can do a video describing your video design methodology, techniques and best practices? No small task , but perhaps a pivotal gift to the genre?
Thank you for your nice words! I once mentioned how I create my videos (in a channel update video). The most important ingredient is to have a clear use case and a typical viewer in mind...
Hi Andreas, very good as always!! I am looking forward to your video on LiFePo4. During the summer I did some test with an ESP, a 700mAh LiFePo4, an 1W/6V Solar panel and a very cheap TP5000 charger. The battery and the charger output are directly in parallel, thus no need for a power path. All power lines should be kept short and thick enough though. I am also just keeping the current limit at 1A and it works just fine. The TP5000 has a step-down converter and this is not optimal with respect to maximizing the power, but it seems at least to be self-regulating. Too high currents are anyhow no problem with a 1W panel. As you have shown in one of your other videos the TP5000 has a very small hysteresis until it starts charging again once the battery is full. However, there is a not used pad that is connected to the chip select. It is possible to solder a thin wire to this and enable/disable charging by yourself. You can check "battery full" via the green LED level, then disable the TP5000 and regularly check the battery voltage to decide yourself when you want to enable charging again. There are also 2 unused pads parallel to the onboard shunt. I used this just out of curiosity to observe the charging current with an ADS1115. In a second setup I just connect the solar and TP5000 parallel of the LiFePo4 without any modifications or measures. During the day the battery is floated around 3.55V and during the night it gets some relief... I really wonder how long it takes to kill the battery by this. I find a lot of "opinions" on this matter, but no real hard facts or data sheets. If there are any battery experts around, I am still keen to learn.
I only used Li-Ion batteries during the last winter and one was dead a few weeks ago ( I do not know, why: Low or too high temperature or something other). The voltage also behaves as you describe. I will see how the LiFePo4 battery behaves during the next winter. This one is also better protected and probably will not get the full temperature swing like the one on the roof.
Welcome back again from biking! My decision tree and life is much easier: 1. Wifi -> mains power. 2. For devices requiring battery (having a lot of them): -> 433Hz + RFLink (also for letterbox, windows, water tank of dehumidifier etc) OR Zigbee OR Homematic device. All bound together in a middleware, which is ioBroker in my case. The only unsolved issue up to now: Battery powered epaper display with some text and figures.
Here life is not so easy. I agree with 433MHz OOK and maybe I should use it more (I have an RFlink-Wifi Bridge). The mailbox notifier is inside the mailbox which is a faraday cage. Only LoRa was capable to escape this prison ;-) And using Wifi for sensors for me is easier because I do not need an additional 433 transmitter chip. I have a few Zigbee sensors in my lab and I love them. But so far I did not program one myself. So I can only use what I can buy (PIR, switch, temperatue, etc. Did you already program a Zigbee device?
I'd be keen on hearing about your new version of the mailbox notifier. I've been considering building something like this myself since I rarely get mail, and checking it even every few days is often pointless, but I don't want to miss 'important' mail.
I want something like this - community mailbox has a key they put in your box for the larger parcels that don't fit. I would build a slot for that key, in addition to a 'please come get your crap' button that triggers a notifier. almost all mail is junk except the parcels. Knowing they want the large box back I think the delivery person would be inclined to take the time to use the key slot, and/or the button so the box doesn't get overstuffed.
I am looking forward to the new LiFePo4 Episode.LiFePo4 has the perfect Volage Range for 3,3V Electronics and behaves well even on some abuse. I very much like these, but unfortunately they normally don't like to be charged at low Temperatures. In Solar powered outdoor Applications i have mounted them in the mounting post buried in the soil to keep them from freezing Temperatures. Low Temperature LiFeYPo4 batteries might be a solution, but there ar only the high capacity prismatic cells from Winston available. I really like to get some cylindrical low temperature charging LiFeYPo4 Cells
I do not know how they behave at low temperatures. All data I found so far was for charging with high currents. In our applications we only charge with low currents. Do you have info or tests for that use case?
I powered a raspberry pi 3 over about 60 feet of cat 5 cable using an old printer power adapter and a drop down voltage regulator... worked flawlessly for many many years outdoors in Alaska
I would love to see some talk about supercapacitors (which are now much more affordable in diy class projects), and the affordability of adding a qi coil to a project. Between those two, many ultra low power devices could be topped up in a matter of minutes without having to open a waterproof case.
Super caps could be interesting for solar powered low power projects because for the capacity, they are quite big. For which use case QI coil charging would fit?
Glad to see you're back making videos! Replaceable batteries seem like a great solution. I'm guessing the average person is too lazy to bother though, which is why we don't see many options on the market. 👍
@@AndreasSpiess Canceled due to all the turmoil in Afghanistan? Hopefully you can do it later, you have more nice traveling to look out for. I looked up the road and it really must be an amazing and adventurous journey! I hope/assume the Rhine journey was also very nice and you had a great time. Stay safe!
I love those ESP32/ESP8266 boards with OLED and an 18650 holder on the back.. sure, they are a bit on the large side, but they've got everything you need to deploy a remote sensor somewhere. Sometimes I just wish they were available in a version with an antenna plug (uFL) instead of the pcb antenna, for situations where I need a bit more wifi range.
The TPL5111 Nano-power system timer may be of interest. I have used this in the past to power up / wake up various boards that would otherwise consume many microamps when in sleep.
Nice overview. I use a 100W solar panel in combination with recycled 12V-7Ah lead acid batteries (2 to 4 in parallel). Endless power... Why the lead acid batteries ? I get them for free, so you can't beat the price.
I want to add one option to the List: Your power tool battery - you can get them cheap on sales and they come with logic to protect them (like 18V 4 AH)
Hello Andreas. Thank you for including Alkaline batteries in your power solution list. Simple is sometimes best. I built a mailbox monitor circuit February 13, 2018 and the same two AA Alkaline batteries are still powering my circuit (3.5 years). The 2x AAs are soldered together in series. Soldering eliminates the possibility of corrosion and poor connections in battery boxes. The PIC microcontroller is in SLEEP mode 99% of the time, only woken up when the mailbox lid is opened. Then a LED is flashed until the circuit is reset by me.
Thank you for the research effort and sharing your knowledge. For the vast majority of my little project, the LiFePO4 option looks to be superior! In the limited cases where I need 5V to drive a bright LED, that should be easily accomplished. 👍
I hope a quick question: I'm pretty new to the esp32 dev world. I have an intent to do some home automation for a zoned HVAC upgrade. Main interest in that regard is to make esp32-based LCD displays for each room. (System manager will likely be on an STM32 device.) So, in addition to the LCD, there's a need for temp sensors with each device. I'm familiar with I2C, SPI and other protocols (primarily with msp430 devices using C with direct port management and access). The problem is the bewildering array of ESP32 devices. Suggestions for a dev board for initial development and testing??? I'm a NOOB in the wilderness when it comes to what I thought would be a "simple" search... TIA
@@Bob-Is-A-PotterNow Most ESP32 dev boards use the same chip (if you do not select an -C3 or -S2/3 version). The form factor and other components (like battery management) are different (none offers LiFePo4). You should find a video with an overview of some boards on this channel. Maybe you will even find a board with an LCD on it that suits your needs.
A 5V USB "UPS" can be very easily implemented externally with an off-the-shelf rechargeable USB battery pack connected in series in-between the little USB power supply and the USB device. E.g. I have a WWVB PSK VLF Radio Clock experimenter circuit card, and if the power fails then it will not display the time until very early in the next morning (syncs at ~01h00 local). So I've simply added an external 20,000 mAh USB battery pack in series with the USB power cable, and it provides the "UPS" function. Such battery large packs are often on sale for as little as ~$20, and they provide a good solution for some use cases. There are also cheaper ~$3 versions available at the Dollar Stores. Cheers.
You are right. But keep in mind that a lot of power banks switch the output off if you start charging them. And you do not get this information before you buy and try them.
During the Super Power project they looked at different LDOs. But so far, I do not have a plan to create a video about it. Mainly because most of them are not available as a module and so useless for a lot of viewers.
Regarding the comment at 8:29 about the lack of development boards that can minimize power consumption, I found out that esp32-c6 dev board comes with a handy jumper that isolates the module from all peripherals, dropping it's deep sleep power consumption to 10uA.
For small currents some negative Temperatures is no big Problem for many Battery types.The Impedance rises, but the Voltage is still the same. LiFePo4 Batteries don't like to be charged at temperatures near or below 0° C - you have to reduce the Charging current significantly. In outdoor applications I placed the Battery in the mounting post below the ground, to keep it warm. For the Electronics You might use some kind of conformal coating to protect it from moisture.
Most of our solar powered garden lights work like that. They simply have an LDR and a transistor to switch the light on when there is no light anymore.
Hi Andreas, your channel is an invaluable source of information for me. Thank you, you frequently mention the use of bare bones ESP32 boards, do you make these up yourself and how hard is it? Do the smd resistors come mounted on the circuit board or do you need to buy and mount those too? There are a few videos on UA-cam showing people making these boards up but it does not seem straightforward to solder. Thank you!
1. We often use ESP32 modules that include everything needed for barebone usage. 2. You can design your PCBs and, if you do not choose too small SMD parts, can solder them by hand or by using a hotplate (google) 3. JLCPCB offers a service where they assemble your board with their machines. A service I often use lately
It would be very interesting to have a video on 24/7 applications using SD cards. It is not clear how to lower it current draw while not used, nor the best way to disconnect them safely.
At 12:06 Why have the MCU hold the circuit on? Wouldn't a self latching one be better and just use the MCU IO to switch off circuit? Just wondering if I am missing something as people(seen this a few times lately) seem to not like using a self latching circuit? As an example of what I mean use an MCU IO pin to replace the off button with the circuit shown at 2:50 in "EEVblog #262 - World's Simplest Soft Latching".
I think that my 2 transistor solution is very similar to Dave’s proposal. We need the mechanical switch to give the signal that the mailbox lid is open and the GPIO to signal that the work is done…
LFP batteries are nice solutions the problem is that charging circuits and protections are very very rare for small devices as they are mainly used for energy storage.
Consider FeRAM for the last case ... these have better retention specs (about 10^10 to 10^14 cycles), and faster rW times, albeit more expensive than EEPROM.
Must make a project power supply out of the 3000F 2.7V (3Wh) super capacitor and solar panel ring that I found washed up on a beach. The circuit board it came with seems to have issues. The boost regulators, of which there are 3 in parallel, seem to occasionally suffer from one getting warm with no apparent load. The bit I want to get right is the capacitor charging circuit, don't want to blow it up. If done right I see it having the potential to run a project self sufficiently for a decade or more. Expected to survive a million duty cycles.
Super caps are good for low power application. My awning wind protector uses such caps. Maybe they are also better for harsh weather conditions. I do not think they will blow up if you solar panel is small. They just might loose their capacity if overcharged.
Thanks for all you do on your channel. I've learned a lot over the past year in following you. A question about your latch circuit at 11:54 - if you wire a momentary reed switch from 5v to the load in order to wake the MCU up, wouldn't that put 5v onto pin 2 of the NDP6020P in your diagram? Is that ok? I can see how it might be "equivalent" to the gate energized and current flowing.
Thanks andreas. You always come up with awesome videos addressing 100 of issues. I am currently working on a datalogger using ttgo tsim-call. The board is mostly in deep sleep mode so I have used ULP for pulse counting. My application needs to run on battery for 3 years. I want you to suggest me a battery. Currently my power consumption in deep sleep mode is 0.7mah
With your numbers you can calculate the size of the battery. It is probably quite big. I think you would have to build an optimized board with lower sleep current or switch the board completely off as I showed in the video
Your board does not only contain the ESP32. Maybe you watch my board comparison videos. Or you measure the current consumption of your board in deep sleep
I would like to see a use case for running on a "too small" power source, I have a project where I only have a 4.2v 75mA supply, but need to periodly need to send mqtt data to home-Assistant
Hello Andreas. I little bit longer question. There is one use case I can not find an answer anywhere. For custom iot made project, I would need to have battetry operated & wirelessly comunicated module, that can live on batteries for at least one year, and can receive & act on message in seconds. There will be maybe one action=message received in monht or so, but when it arrive, it needs to act fast. All other time it may be in some "sleep but lissening for message" state. There are such a devices on the market, like z-wave/zigbee TRV, or door locks. Those run on few cells batteries 1-2 years, and act on o request in a seconds. I tested spirit zigbee TRV, and when I change the tempereature in Home Assistant, TRV receive it in a seconds, and run on 2 AA bateries over one year. Considering it has to move a small motor few times a day during winter, it is pefect example that it is possible. It uses FLiRS (Frequently Listening Receiver Slave) method for it. But problem is, I can not find any module like it for custom made projects. It might be any wireless protocol (zigbee, zwave, bt, espnow, or any radio module like nrf24l01...). Do you have any idea for this purpose? Thank You for any answer. Peter.
I do not know of Zigbee modules for DIJ. But maybe you can use the PCB of one of the devices you described. They should have an output pin you can use for your purpose.
I do not know the ESP32 cam in particular. But they are most probably 3.3-volt designs with an LDO to reduce the 5 volts as most development boards. So it should be possible to power them with 3.3 volts (as showed in this video). If you want to power them with 5 volts then a power bank is probably the easiest way. I also did a video about "poor man's" UPC which also could be used. Pay attention to power banks: Often you can only charge or discharge them. Then they are not useable for continuous operation.
@@AndreasSpiess The ESP32-Cam might amuse you because they can support facial recognition on your cats to prevent them from coming through their pet doors with birds or mice in their mouths. While the ESP32 board in the ESP32-CAM is certainly 3 volt logic, the data sheets specify 5 volts (and sometimes 2 amps) to ensure there's enough juice to power the camera module. There's a 5 volt on board regulator to drop the voltage to logic level. Many, MANY thanks for your SUPERB videos! I have learned so much from you.
Did you get your helium hotspots yet? Was hoping to see how you power them and also maybe even provide some Spiess solution for internet coverage. Thanks for awesome content as always. :)
@@eugy2008 oh, i didnt get that. got a few on the way anyway. I think If poeple get roi pretty fast, it should not matter if is a scam as long as it works. And looking how the neighbours are earning I think it ok. Looking forward to adding sensors to the helium network myself by the way. I love making things works, so when i some day have the time, i hope andreas videos is avalable for me to make more serious use of it. But I seriously dont understand why some say it is a scam...
Grüezi Andreas ^^ Immer wieder enttäuschend zu hören, dass von etwas Spannenden nichts wirklich am Markt existiert. Vl. wärst genau du der Richtige dafür sowas zu entwerfen und auf den Markt zu bringen :D KiCad ist ja gratis & services wie JLCPCB können günstig Platinen in "Massen" herstellen. Würde mich freuen einen eigenen Shop von dir zu sehen :)
Als ich jung war habe ich HW verkauft. Heute ist dieses Geschäft so uninteressant dass ich ich die Finger davon lasse. Ich habe es ja nochmals mit dem "Super Power Projekt" versucht und bin wegen der Chipknappheit wieder auf die Schnauze gefallen :-(
EEPROM and Flash are different technologies. The number of write cycles for an EEPROM should be well above a flash memory. But still some wear is to be expected.
Very informative, as always! I was wondering how worse off one would be with a solar USB power bank? They tend to be very cheap, robust and just a matter of plugging them in via USB. What’s the breaking point in terms of cost/performance compared with a DIY panel+battery+electronics?
Hi Andreas, I learn a lot each time I watch your videos. However this time I was surprised by the advice to use disposable batteries, these causes environmental issues and I guess we would be better off using 18650 that can be changed then recharged for later use. I've been trying to eliminate as much as possible the use of AA or AAA batteries at home when I realised the pile or difficult to recycle batteries I was generating. in addition the rechargeable version of those are not very good.
I suppose depends on the area - in some places disposable batteries are easier to recycle than others. Anywhere that you can recycle one you can probably recycle the other.
I propose primary batteries only for applications where they live for a year or longer. So I do not see big problems compared to all other waste we produce. For the other scenarios I propose rechargeable batteries.
Txs for this video as it's very timely. I'm building a water level sensor (SR-HC04) for a water tank and want to go the battery operated route if possible. Initially my thoughts were deep sleep and automatically wake up a few times a day to send the water level. However in discussions with my neighbor he would want to see the level at a particular time (i.e. use case #5). Also what's the difference between use case #3 "battery operated and don't sleep at all" and use case #4 "on 24/7"? Is it possible to have an event driven use case (without a physical switch/relay etc.) and get a few months of usage without needing a Tesla battery wall :)? How do I go about dimensioning the battery requirement? Love your videos!
If you use a properly designed setup and deep sleep you can get a few month life. But pay attention to ultrasonic sensors, You also have to switch them completely off during deep sleep. So you need a custom-designed diagram probably using an ESP32-WROOM module plus a FET to switch the sensor (use case 4). Use case 3 does not work for a long time because they are always on.
Hi Andreas, Thank you for another great video. In 11:45, you mention the p-channel mosfet solution you proposed in video 101 is not reliable. What are the exact issues one can encounter? I was just about to build that for an arduino circuit. Thanks!
Thank you @@AndreasSpiess. I built it with just a p-channel mosfet, and tried (Arduino Uno, with NDP6020P or IRF4905PBF), it did not work. With the new circuit you showed in this video it did. Thank you!
Hi, great video. Have you a video in which you comment the problems about "only one mosfet" and why you change to the two mosfet version? Or could you comment ? Thanks.
Regarding OLED display pinout: It seems "impossible" to know the Vcc/GND pinout on those OLEDs. I have ended up making solderbridges on my PCBs to select Vcc & GND.
AFAIK they sell these small ones in 2 versions. Becaus I know the issue I pay attention (and have a few of each version in my drawer). But solder bridges are also a good idea.
@@AndreasSpiess Yes there are both versions, but my experience is that it does not help studying the Aliex ad. On the positive side, I get a partial refund when the delivered differs from photos. ;-)
I never worked with the ME6211 and the board with one of the lowest deep sleep current in my test used an HT7333… Maybe somebody else has more information?
For HT7333 the max. quiescent current (the one you have even without a load - the one you care about in the deep sleep) is 7 uA. For ME6211 it's 60 uA (looking at the datasheet). (other sources say it's 4 uA vs 40 uA). Still it's 10 times more current (energy) drawn by the LDO during the sleep time - something that makes HT7333 vs ME6211 choice rather obvious :). For example the ESP32 processor lowest deep sleep current is 10 uA. It doesn't take the other things (like the crystal) into account - but still for my board the HT7333 + ESP32 (WROOM32D module) when they sleep, together they consume around 50 uA - still lower than the ME6211 alone :). Doubling that with ME6211 would make the device last 2x shorter on the battery..
While looking at specs, HT7333 may not provide sufficient peak current (250 mA max vs 500 mA min required for ESP32-S2). Same check for ME6211 gives 500 mA max that sounds good. Not sure what a block consumes so much power inside ESP32-S2, maybe Wi-Fi (~310 mA peak) plus something else? In no RF mode chip takes mere 19 mA max, so HT7333 fits here well. Do you know other LDO's for 500 mA?
@@NikolaiVarankine Sorry for late reply. I won’t touch any LDO supplying less than 500mA when using WiFi etc. in a project. May be bulk capacitor can used to cover spikes in current demands. Sometime ago I saw a list of LDOs somewhere. I haven’t verified all the data. But it seems a good spot to begin when choosing LDO. Here is that list. LDOs (Low power dropout regulators) MAX1724: Range voltage: 0.91 - 5.5 V Max current out: 150mA Quiescent current: 1.5 uA Drop out voltage: MCP1700: Range voltage: 6 V Max Max current out: 250 mA Quiescent current: 1.6 uA Drop out voltage: 178 mV Ht7333: Range voltage: 12 v Max current out: 250 mA Quiescent current: 4 uA Drop out voltage: 170 mV HT7833: Range voltage: 8 v Max Max current out: 500 mA Quiescent current: 4 uA Drop out voltage: 360 - 500 mV MCP1825: Range voltage: 6 v Max Max current out: 500 mA Quiescent current: 120 - 220 uA Drop out voltage: 210 - 350 mV XC6203(XC6203E33): Range voltage: 8 v Max Max current out: 400 mA Quiescent current: 8 uA Drop out voltage: 300 mV ISL91107IR: Range voltage: 1.8 V to 5.5 V Max current out: 2A Quiescent current: 45 uA Drop out voltage: Buck-Boost 96% efficiency TPS73633: Range voltage: 5.5 V Max current out: 400 mA Quiescent current: 10 mA??? Drop out voltage: 75 - 200 mV AP2112: Range voltage: 6 v Max Max current out: 600 mA Quiescent current: 55 uA Drop out voltage: 250 mV RT9013: Range voltage: 5.5 v Max Max current out: 500 mA Quiescent current: 25 uA Drop out voltage: 250 mV AAT1217: Range voltage: 6 V Max current out: 600 mA Quiescent current: 300 - 500 uA Drop out voltage: stepup 93% efficiency TLV73333: Range voltage: 5.5 v Max Max current out: 300 mA Quiescent current: 34 uA Drop out voltage: 150 mV LM2936: Range voltage: 5.5 V to 40 V Max current out: 250 mA Quiescent current: 20 uA Drop out voltage: 400 mV TC1262: Range voltage: 6 V Max current out: 500 mA Quiescent current: 130 uA Drop out voltage: 650 mV SPX3819: Range voltage: 16 V Max Max current out: 500 mA Quiescent current: 8 uA Drop out voltage: 550 mV AMS1117: Range voltage: 12 v Max Max current out: 1 A Quiescent current: 5 mA Drop out voltage: 1.3 V Hope its helpful.
I have a question for the big brain people 😜. What development board do you suggest for me to start with? My 9 & 11 year old son's want to get into IoT and automate our motorHOME. Since we live in it full time, we want to have fun AND protect ourselves with gas detection, water detection, and fun stuff. I have an Arduino and a raspberry pi, but it seems like it will get WAY too expensive to use those for every project. I know very little knowledge, will be learning with my kids and using a LOT of tutorials. We will eventually be off grid, completely and only using our 24v solar system. Thanks!!!
Most of us use Chinese boards with either ESP32 or ESP8266 chips because they offer WiFi and the ESP32 Bluetooth. And a Raspberry as a server. Then the price is not too high. You find many videos on this channel where I compare the different boards. I would always start with the needs in mind. There is no "one size fits all" board
Hi Andreas, thank you so much for this video. Where can I buy the transparent box you have used to store your circuits powered by solar boards? Thanks!
I do not use buck converters for such small voltage differences. Too complicated (and always the risk of RFI). For bigger voltage differences I also use switchers because the LDOs get hot and waste energy.
@@AndreasSpiess I tred solution with XC9236A33CMR buck, it works with ESP8266 down to 3.35 volts on the battery (it do about 3.25 volts on the ESP). With S-8550 (8551 have different pinout) I will try soon.
Hello Andreas, @2:24 you mention that you power the unit by soldering the wires directly to the board. As an electronics fumbler, I would like to know more. Which pins and at what voltage do you solder the wires to? I don't want to use the USB connection if possible.
I tried everything to get a power supply with no noise for a seismic sensor design of our company back in 1987. After weeks of research and testing, I ended up using batteries. Everything else was just too damn noisy. A power supply designs are dictated by their use. Sometimes you can get away with a simple LDO. However, sometimes there is no solution but to use batteries.
You are right. I also tend towards batteries if noise is an issue. To "characterize" a power supply for my radios I compared the noise with a battery, with a server power supply, and with ferrite beads included. The battery sets the reference...
Concerning power-supplies and Meshtastic, I see your recent 2021-09-05 video on power supplies. Being in the (periodically) cold north, it would be nice to power this with super-capacitors with no batteries. I've seen some videos on this type of circuit, but was wondering whether you'd want to address it? I'll copy this into your recent video on power supplies.
Most of the ESP32 boards run on 3.3V (with a 5V regulator to be powered from USB). You should be able to connect 3.3V directly to the 3.3V pin. So you have many different possibilities for powering like mains (via USB), Li-Ion (with a 3.3v regulator or LiFePo4 batteries without a regulator.
Hi, using the ttgo t-call esp32 sim800l have you had problems with the 3.7v lipo battery not cutting in when attached to the JST Connector connector for if the main usb type c 5v goes down. Used as a back up battery? Regards
Do you use a specific brand of usb chargers? I'm looking low idle consumption and after some reading it seems like there is quite a variety, even in products from the same manufacturer.
I wondered if a simple DC self latching relay might be a good choice to switch directly to the battery after the initial battery voltage falls. There's no voltage drop or power required to hold it after it's pulsed open or reverse pulsed closed. There seem to be a lot of these "bi-stable" flip flop relays available are there any really tiny ones? Maybe that's already been the discussion, I'm slow sometimes. Of course there's probably going to be a big spike on the supply voltage...
Hello Andreas, I am new to the world of microcontrollers and micropython. I use a ESP8266 dev kit on a breadboard. The ESP is powered by the (micro-)USB connection to the computer, necessary for coding and executing Python scripts on the ESP. For additional devices, I use a power supply module on the breadboard which provides 5V and 3.3V. Question: do I have to connect 5V or 3.3V from the breadboard power supply to the respective pins on the ESP dev kit? Thank you for your very informative videos. Regards.
4:18 I want to make a battery powdered project using ESP32-S3 which is going to use a 4.2V Lipo as power source. The project is also going use 10 LEDs. The ESP32 with WiFi is going to be powered for around 5 minutes at a time and then go back to deep sleep. Question: Between the Battery and ESP32, should I use the HT7333 Voltage Regulator(250ma max output), or should I use another Voltage regulator like AMS1117?
I want to build a clock with a lot of LEDs. Since it draws a lot of current it and is on 24/7 it should be wall powered. But the voltages that the addressable LEDs need is usually different from most dev boards. How to keep it simple and also not too hot?
I've been locking at those for my project. Interestingly, only the large LTO batteries seem to have those low temperature charging capabilities. The small, AA size do not, at least from my research on aliexpress. Let us know if you find different info.
Hi, get the datasheet of this cells (scroll a little) : says for LTO1865 - 15°C for charging. Hope it helps. shop.gwl.eu/LTO-technology/Pack-of-5pcs-LTO1865-Rechargeable-Cell-2-4V-1300-mAh-Lithium-Titanate.html?force_sid=0qra68almb5ma1i1k3mdas3718
The problem of LTO batteries is that you do not get a lot of chargers or protection circuits. In addition, you need 2 in series to get to the needed 3.3 volts. But of course, in harsh conditions, it might be a good solution.
The size of the capacitor does not matter too much (as my tests show). The current peaks are very short and it seems the HT7333 can deal with it. Average cuttend consumption of an ESP32 is only around 100mA
I'm trying to power an ESP32 with 2 AA alcaline batteries and using a step up DC-DC (MT3608) to make it to 5V. The red led blinks all the time non stop. This setup works for the NodeMCU ESP8266. It also works using a simple phone charger. Any ideas?
Hello Andreas, welcome back.
I have a little tip for your power supply at 2:37 (Tenstar 230V). A strain relief should be attached for the 230V cable. I use a cable tie in such a case. I push the cable in a little further and tighten a cable tie. In this way I achieve that there is no pull on the soldering points. In Germany, strain relief is mandatory.
Good point. I agree.
Power over Ethernet (POE) or the newer PODL are options for LAN connected devices. 10 Mbps at a 1000m for (Single Pair Ethernet) SPE-PODL. PODL is much simpler to implement than POE as the power supply current doesn't have to run through the magnetics.
Agreed (I made a video about POE). I could have added the use case for projects with wired Ethernet, you are right.
Concerning PODL: Is this already widely adapted? I never heard of it
Hi Andreas, good to have you back in front of the first row! Your current favorite board at 2:18, which one is that?
I added the links to the two boards to the video description.
Thank you kindly, Andreas! 👍
Great job with putting those usecases in order! :) And I share your love for HT7333! With small correction, that its dropout voltage is 150 mV - both in the datasheet and personally tested :). With battery going down to 3.45 V it keeps giving pure 3.3. Battery going down to 3.44 V - it goes down to 3.29 on the output, and so on - going down in the linear fashion, always 0.15 V below the battery voltage. Which is still great and more than enough for 3xAA batteries. And ESP32 still keeps working even with 3.0 V ;) (which means 3.15 V from 3xAA, which is when they are almost 100% empty :) ).
That is what I also had in mind. But this Holtek datasheet www.angeladvance.com/HT73xx.pdf says 90mV (@40mA). That is where I had my value from
@@AndreasSpiess Oh my!! I was very sure about that 150 mV, but indeed the datasheet says 90... Is my memory soo bad?
Noo! :) I must have remembered the value well from the time you showed it in episode 58 (small cell battery powering sleeping ESP8266) many years ago!! There you said and SHOWED on the datasheet the value 150. They must have changed the datasheet in those few years :). Plus my own tests always showed consistent 0.15 dropout.
We can agree on 150mV. As I said, I also had this value in mind. But then I looked it up to have a "proof"...
I've been designing around single cell lipo batteries for about a year now as i've been developing my invention and i've found that they do wonderfully if the power consumption is managed correctly. Integrating a lipo charger in the form of an MCP73831 is extremely easy and it can charge the batteries I use very very quickly. I just throw in an AMS 3.3V LDO (the same vreg found on the devkit modules) to verify proper regulation.
That aside, the video is fantastic as always
I agree. They work fine for many applications, particularly if you can charge them easily (not remote).
Something about the use of EEPROM. We had written a small library, with writes the information not allways at the same memory cells. If you do it right, the 10.000 cycles "problem" is gone. We had made a test - we wrote 1K blocks to an EEPROM about the size of 64k. The first data lost was around 2 Mio cycles :-) Detected with a simple CRC in the blocks. Something similar is done by the controllers of SD cards and USB Sticks.
Very interesting. Did you also compare how many circles were possible without the library? And is the library available?
Hi, I use FRAM: 10'13 read/write cycles, 150ns...! See Fujitsu for example.... 🧐
I think we did at as filesystem. enough writes to certain block it swapped to next. I think all our blocks had info what file chain it belongs and what is write amount. so when we boot we scan eeprom block headers and create toc in ram.
Edit: Need to check these FRAM chips. I think they also wear out when reading
Love it. The simplest version I know of is to zero everything, then only ever write in full eeprom write blocks. Scan to the first available detected block and write there. When full zero everything. using a smarter algorithm like yours on battery is probably wise to minimize cpu time scanning.
@@LimbaZero Please get Fujitsu Product Overview datasheet. Also UA-cam will Show you good Comparison. When write speed is a concern: also FRAM. At least in my projects. Greetings Henry...
I'd like to amplify comments about the benchmark Andreas has established with his videos. This particular one is a great in so many respects:
It (quite properly) prioritizes a methodology for analyzing needs;
It provides simple practical recipes for bears-of-little-analog-brain;
It's a master class in video design, and elegant, cost-effective production, saluting many well-established golden rules, and avoiding gratuitous distraction.
Andreas: welcome back. How do you crank out didactic masterpieces like this week after week? Maybe one day you can do a video describing your video design methodology, techniques and best practices? No small task , but perhaps a pivotal gift to the genre?
Thank you for your nice words! I once mentioned how I create my videos (in a channel update video). The most important ingredient is to have a clear use case and a typical viewer in mind...
@@AndreasSpiess Yes indeed, but you have a plethora of other production values that make a huge difference, to clarity and efficiency.
Hi Andreas, very good as always!! I am looking forward to your video on LiFePo4.
During the summer I did some test with an ESP, a 700mAh LiFePo4, an 1W/6V Solar panel and a very cheap TP5000 charger.
The battery and the charger output are directly in parallel, thus no need for a power path. All power lines should be kept short and thick enough though.
I am also just keeping the current limit at 1A and it works just fine. The TP5000 has a step-down converter and this is not optimal with respect to maximizing the power, but it seems at least to be self-regulating. Too high currents are anyhow no problem with a 1W panel.
As you have shown in one of your other videos the TP5000 has a very small hysteresis until it starts charging again once the battery is full. However, there is a not used pad that is connected to the chip select. It is possible to solder a thin wire to this and enable/disable charging by yourself. You can check "battery full" via the green LED level, then disable the TP5000 and regularly check the battery voltage to decide yourself when you want to enable charging again.
There are also 2 unused pads parallel to the onboard shunt. I used this just out of curiosity to observe the charging current with an ADS1115.
In a second setup I just connect the solar and TP5000 parallel of the LiFePo4 without any modifications or measures. During the day the battery is floated around 3.55V and during the night it gets some relief... I really wonder how long it takes to kill the battery by this. I find a lot of "opinions" on this matter, but no real hard facts or data sheets. If there are any battery experts around, I am still keen to learn.
I only used Li-Ion batteries during the last winter and one was dead a few weeks ago ( I do not know, why: Low or too high temperature or something other). The voltage also behaves as you describe. I will see how the LiFePo4 battery behaves during the next winter. This one is also better protected and probably will not get the full temperature swing like the one on the roof.
Welcome back again from biking!
My decision tree and life is much easier:
1. Wifi -> mains power.
2. For devices requiring battery (having a lot of them): -> 433Hz + RFLink (also for letterbox, windows, water tank of dehumidifier etc) OR Zigbee OR Homematic device. All bound together in a middleware, which is ioBroker in my case.
The only unsolved issue up to now: Battery powered epaper display with some text and figures.
Here life is not so easy. I agree with 433MHz OOK and maybe I should use it more (I have an RFlink-Wifi Bridge). The mailbox notifier is inside the mailbox which is a faraday cage. Only LoRa was capable to escape this prison ;-) And using Wifi for sensors for me is easier because I do not need an additional 433 transmitter chip.
I have a few Zigbee sensors in my lab and I love them. But so far I did not program one myself. So I can only use what I can buy (PIR, switch, temperatue, etc. Did you already program a Zigbee device?
@@AndreasSpiess No, Ifor zigbee, Homematic & 433MHz I just use the sensors, which I can buy.. And that is a lot. The rest is done with ESP sensors.
Wow, I hadn't seen this one yet. As always, great coverage for the various options with clear and concise reasons for the use case. Thanks !!!
My pleasure!
I'd be keen on hearing about your new version of the mailbox notifier. I've been considering building something like this myself since I rarely get mail, and checking it even every few days is often pointless, but I don't want to miss 'important' mail.
I assume it will appear in one of the next videos. It is quite useful...
I want something like this - community mailbox has a key they put in your box for the larger parcels that don't fit. I would build a slot for that key, in addition to a 'please come get your crap' button that triggers a notifier. almost all mail is junk except the parcels. Knowing they want the large box back I think the delivery person would be inclined to take the time to use the key slot, and/or the button so the box doesn't get overstuffed.
I am looking forward to the new LiFePo4 Episode.LiFePo4 has the perfect Volage Range for 3,3V Electronics and behaves well even on some abuse. I very much like these, but unfortunately they normally don't like to be charged at low Temperatures. In Solar powered outdoor Applications i have mounted them in the mounting post buried in the soil to keep them from freezing Temperatures. Low Temperature LiFeYPo4 batteries might be a solution, but there ar only the high capacity prismatic cells from Winston available. I really like to get some cylindrical low temperature charging LiFeYPo4 Cells
I do not know how they behave at low temperatures. All data I found so far was for charging with high currents. In our applications we only charge with low currents. Do you have info or tests for that use case?
Wow, even though i've done my research about this topic, your video always inspiring, especially those summary. Thank you :)
Glad you liked it!
Glad to see you are back and making new videos. I hope you had a great vacation.
I only had a break from UA-cam. Because this is my hobby, I still had my normal job :-( But I had the two weeks bike trip with my wife.
Hello Andreas, a very useful video for the maniacs to reduce consum of our projects. You are the best!!!! Thanks from Spain!!!
You are welcome!
I powered a raspberry pi 3 over about 60 feet of cat 5 cable using an old printer power adapter and a drop down voltage regulator... worked flawlessly for many many years outdoors in Alaska
If you start with a high enough voltage that is a good idea. Others call it PoE (Power over ethernet)...
I would love to see some talk about supercapacitors (which are now much more affordable in diy class projects), and the affordability of adding a qi coil to a project. Between those two, many ultra low power devices could be topped up in a matter of minutes without having to open a waterproof case.
Super caps could be interesting for solar powered low power projects because for the capacity, they are quite big.
For which use case QI coil charging would fit?
This describes pretty much my journey for an Solar Powered Outdoor Temperature/Humidity Sensor.
Good that we agree...
Glad to see you're back making videos! Replaceable batteries seem like a great solution. I'm guessing the average person is too lazy to bother though, which is why we don't see many options on the market. 👍
Maybe a lot of people think that rechargeable batteries are better. This is the case for many use cases, but not for all...
@@AndreasSpiess Split the difference, and replace rechargeable batteries?
Welcome back! - hope you had a restful summer break! Thanks for the video
Yes, a little while without producing videos was good for me (I still had my normal job)...
Great video as always 👍
I love your great experience in problem solving!
thanks for sharing your experience with all of us 👍😀
My pleasure!
Hi Andreas, thanks for the video and glad you’re back. How was your motorbike trip?
The motorbike trip is still ahead. Tajikistan was cancelled and I drove 1000km along the Rhine river with my wife and our bicycles.
@@AndreasSpiess Canceled due to all the turmoil in Afghanistan? Hopefully you can do it later, you have more nice traveling to look out for. I looked up the road and it really must be an amazing and adventurous journey! I hope/assume the Rhine journey was also very nice and you had a great time. Stay safe!
Yes, it was cancelled because of Afghanistan. I do not think I can doo this trip soon. But there is hope ...
What a critically useful information. Your videos are super helpful!
Happy to hear that!
I love those ESP32/ESP8266 boards with OLED and an 18650 holder on the back.. sure, they are a bit on the large side, but they've got everything you need to deploy a remote sensor somewhere. Sometimes I just wish they were available in a version with an antenna plug (uFL) instead of the pcb antenna, for situations where I need a bit more wifi range.
I like the T-Beam for my projects, too. Just keep in mind: These boards are not optimized for deep-sleep.
The TPL5111 Nano-power system timer may be of interest. I have used this in the past to power up / wake up various boards that would otherwise consume many microamps when in sleep.
Good point. If I remember right, Kevin Darrah has one in his trigboard.
🤯 Now, that's what I call a concise brain dump!
Thanks, Andreas. That's exactly what I needed 😎
Great! You are welcome.
Nice overview. I use a 100W solar panel in combination with recycled 12V-7Ah lead acid batteries (2 to 4 in parallel). Endless power...
Why the lead acid batteries ? I get them for free, so you can't beat the price.
Lead acid is very good if size/weight does not matter. They also withstand harsh environmental conditions.
@@AndreasSpiess Indeed, and even below freezing point they still are able to charge/uncharge quite well.
I want to add one option to the List: Your power tool battery - you can get them cheap on sales and they come with logic to protect them (like 18V 4 AH)
Thank you!
Hello Andreas. Thank you for including Alkaline batteries in your power solution list. Simple is sometimes best. I built a mailbox monitor circuit February 13, 2018 and the same two AA Alkaline batteries are still powering my circuit (3.5 years). The 2x AAs are soldered together in series. Soldering eliminates the possibility of corrosion and poor connections in battery boxes. The PIC microcontroller is in SLEEP mode 99% of the time, only woken up when the mailbox lid is opened. Then a LED is flashed until the circuit is reset by me.
That is interesting! You even can blink the LED!
Nice work Andreas, has answered a lot of my questions
Great to hear! Thanks.
Thank you for the research effort and sharing your knowledge. For the vast majority of my little project, the LiFePO4 option looks to be superior! In the limited cases where I need 5V to drive a bright LED, that should be easily accomplished. 👍
LiFePo4 is now even more accepted than when I made this video. So you made a good choice.
@@AndreasSpiess 😁
I hope a quick question: I'm pretty new to the esp32 dev world. I have an intent to do some home automation for a zoned HVAC upgrade. Main interest in that regard is to make esp32-based LCD displays for each room. (System manager will likely be on an STM32 device.)
So, in addition to the LCD, there's a need for temp sensors with each device. I'm familiar with I2C, SPI and other protocols (primarily with msp430 devices using C with direct port management and access). The problem is the bewildering array of ESP32 devices. Suggestions for a dev board for initial development and testing??? I'm a NOOB in the wilderness when it comes to what I thought would be a "simple" search... TIA
@@Bob-Is-A-PotterNow Most ESP32 dev boards use the same chip (if you do not select an -C3 or -S2/3 version). The form factor and other components (like battery management) are different (none offers LiFePo4). You should find a video with an overview of some boards on this channel. Maybe you will even find a board with an LCD on it that suits your needs.
@@AndreasSpiess Thank you for the suggestions. In fact, I followed your advice before you left it! Found some very good information, as usual.😁
A 5V USB "UPS" can be very easily implemented externally with an off-the-shelf rechargeable USB battery pack connected in series in-between the little USB power supply and the USB device. E.g. I have a WWVB PSK VLF Radio Clock experimenter circuit card, and if the power fails then it will not display the time until very early in the next morning (syncs at ~01h00 local). So I've simply added an external 20,000 mAh USB battery pack in series with the USB power cable, and it provides the "UPS" function. Such battery large packs are often on sale for as little as ~$20, and they provide a good solution for some use cases. There are also cheaper ~$3 versions available at the Dollar Stores. Cheers.
You are right. But keep in mind that a lot of power banks switch the output off if you start charging them. And you do not get this information before you buy and try them.
Excellent video!! Very helpful! Please consider to make a video that compares different LDOs available.
During the Super Power project they looked at different LDOs. But so far, I do not have a plan to create a video about it. Mainly because most of them are not available as a module and so useless for a lot of viewers.
Regarding the comment at 8:29 about the lack of development boards that can minimize power consumption, I found out that esp32-c6 dev board comes with a handy jumper that isolates the module from all peripherals, dropping it's deep sleep power consumption to 10uA.
That is a good idea!
Have you ever looked into using or keeping batteries (and if required, electronics) varm-ish during winter? (0 to -20 C)?
For small currents some negative Temperatures is no big Problem for many Battery types.The Impedance rises, but the Voltage is still the same. LiFePo4 Batteries don't like to be charged at temperatures near or below 0° C - you have to reduce the Charging current significantly. In outdoor applications I placed the Battery in the mounting post below the ground, to keep it warm. For the Electronics You might use some kind of conformal coating to protect it from moisture.
Now I want to build a mailbox notifier! :)
I like it very much. One of my better builds so far!
I'd like to see a use case of "solar powered device off during the day but on at night"
Most of our solar powered garden lights work like that. They simply have an LDR and a transistor to switch the light on when there is no light anymore.
If a space is not a concern, I would confider a small motorcycle battery. They're pretty good price for the capacity.
Absolutely. Lead Acid batteries are very robust and can be used in low temperatures.
Hi Andreas, your channel is an invaluable source of information for me. Thank you, you frequently mention the use of bare bones ESP32 boards, do you make these up yourself and how hard is it? Do the smd resistors come mounted on the circuit board or do you need to buy and mount those too? There are a few videos on UA-cam showing people making these boards up but it does not seem straightforward to solder. Thank you!
1. We often use ESP32 modules that include everything needed for barebone usage.
2. You can design your PCBs and, if you do not choose too small SMD parts, can solder them by hand or by using a hotplate (google)
3. JLCPCB offers a service where they assemble your board with their machines. A service I often use lately
It would be very interesting to have a video on 24/7 applications using SD cards. It is not clear how to lower it current draw while not used, nor the best way to disconnect them safely.
I never used an SD card in my projects. I always connect my ESPs to the Wi-Fi. So I am no help here :-(
Muy bueno gracias desde España
You are welcome!
Thanks very much. Very insightful
You are welcome!
At 12:06 Why have the MCU hold the circuit on? Wouldn't a self latching one be better and just use the MCU IO to switch off circuit?
Just wondering if I am missing something as people(seen this a few times lately) seem to not like using a self latching circuit?
As an example of what I mean use an MCU IO pin to replace the off button with the circuit shown at 2:50 in "EEVblog #262 - World's Simplest Soft Latching".
I think that my 2 transistor solution is very similar to Dave’s proposal. We need the mechanical switch to give the signal that the mailbox lid is open and the GPIO to signal that the work is done…
LFP batteries are nice solutions the problem is that charging circuits and protections are very very rare for small devices as they are mainly used for energy storage.
I plan a video about these batteries. You get now protectors as well as chargers for them.
Welcome back :)
:-)
Consider FeRAM for the last case ... these have better retention specs (about 10^10 to 10^14 cycles), and faster rW times, albeit more expensive than EEPROM.
FANUC has used this technology to replace battery backed SRAM in their CNC and robot controllers.
I did not know this technology. It is probably a good solution for special cases. Most of my use cases do not run so long.
@@AndreasSpiess They are pin interchangeable with EEPROM, so painless, and fast.
Hallo Andreas, vielen Dank für das Video. 73 de Michael
Gern geschehen! 73 de HB9BLA
Great video, thanks. Are you back from your summer break yet or still not for a couple of weeks?
You are welcome! The normal schedule started today...
Must make a project power supply out of the 3000F 2.7V (3Wh) super capacitor and solar panel ring that I found washed up on a beach. The circuit board it came with seems to have issues. The boost regulators, of which there are 3 in parallel, seem to occasionally suffer from one getting warm with no apparent load.
The bit I want to get right is the capacitor charging circuit, don't want to blow it up.
If done right I see it having the potential to run a project self sufficiently for a decade or more. Expected to survive a million duty cycles.
Super caps are good for low power application. My awning wind protector uses such caps. Maybe they are also better for harsh weather conditions. I do not think they will blow up if you solar panel is small. They just might loose their capacity if overcharged.
Thanks for all you do on your channel. I've learned a lot over the past year in following you. A question about your latch circuit at 11:54 - if you wire a momentary reed switch from 5v to the load in order to wake the MCU up, wouldn't that put 5v onto pin 2 of the NDP6020P in your diagram? Is that ok? I can see how it might be "equivalent" to the gate energized and current flowing.
I’m curious to know what is an acceptable voltage range that determine if a voltage regulator is a low drop voltage or not.
I do not think that you find a valid definition for that.
Thanks andreas. You always come up with awesome videos addressing 100 of issues. I am currently working on a datalogger using ttgo tsim-call. The board is mostly in deep sleep mode so I have used ULP for pulse counting. My application needs to run on battery for 3 years. I want you to suggest me a battery. Currently my power consumption in deep sleep mode is 0.7mah
With your numbers you can calculate the size of the battery. It is probably quite big. I think you would have to build an optimized board with lower sleep current or switch the board completely off as I showed in the video
@@AndreasSpiess isn't the ULP of esp32 in deep sleep mode consuming
Is good option? Or to shift some other chips
Your board does not only contain the ESP32. Maybe you watch my board comparison videos. Or you measure the current consumption of your board in deep sleep
I would like to see a use case for running on a "too small" power source, I have a project where I only have a 4.2v 75mA supply, but need to periodly need to send mqtt data to home-Assistant
I probably would add 2 supercaps in series and a Shottky diode from the battery to the super caps.
Hello Andreas. I little bit longer question. There is one use case I can not find an answer anywhere. For custom iot made project, I would need to have battetry operated & wirelessly comunicated module, that can live on batteries for at least one year, and can receive & act on message in seconds. There will be maybe one action=message received in monht or so, but when it arrive, it needs to act fast. All other time it may be in some "sleep but lissening for message" state. There are such a devices on the market, like z-wave/zigbee TRV, or door locks. Those run on few cells batteries 1-2 years, and act on o request in a seconds. I tested spirit zigbee TRV, and when I change the tempereature in Home Assistant, TRV receive it in a seconds, and run on 2 AA bateries over one year. Considering it has to move a small motor few times a day during winter, it is pefect example that it is possible. It uses FLiRS (Frequently Listening Receiver Slave) method for it. But problem is, I can not find any module like it for custom made projects. It might be any wireless protocol (zigbee, zwave, bt, espnow, or any radio module like nrf24l01...). Do you have any idea for this purpose? Thank You for any answer. Peter.
I do not know of Zigbee modules for DIJ. But maybe you can use the PCB of one of the devices you described. They should have an output pin you can use for your purpose.
Andreas, great concise and informative video. Is there a good coin cell battery that would be good enough for either of the latter 2 use cases?
I do not know. Most coin cell batteries I know are very low current.
LIR2450~120mAh, Can last for a couple of hours.
Could you make a separate video on how to power microcontroller or SBC audio projects via mains PSU where the noise free power feed is absolute MUST.
I am not an audio (noise) specialist. There are better sources for such technology, I think.
@@AndreasSpiess OK, thank you for the answer.
SUPERB! Would you please do a similar show for 5 volt devices like the ESP32-CAM with its associated presence sensors and alarms?
Many thanks!
I do not know the ESP32 cam in particular. But they are most probably 3.3-volt designs with an LDO to reduce the 5 volts as most development boards. So it should be possible to power them with 3.3 volts (as showed in this video).
If you want to power them with 5 volts then a power bank is probably the easiest way. I also did a video about "poor man's" UPC which also could be used. Pay attention to power banks: Often you can only charge or discharge them. Then they are not useable for continuous operation.
@@AndreasSpiess The ESP32-Cam might amuse you because they can support facial recognition on your cats to prevent them from coming through their pet doors with birds or mice in their mouths.
While the ESP32 board in the ESP32-CAM is certainly 3 volt logic, the data sheets specify 5 volts (and sometimes 2 amps) to ensure there's enough juice to power the camera module. There's a 5 volt on board regulator to drop the voltage to logic level.
Many, MANY thanks for your SUPERB videos! I have learned so much from you.
Welcome back.
:-)
@@AndreasSpiess I'd like to see pictures from your trip. Are those coming?
No, I do not think so. Anyway, Tajikistan was cancelled due to Afghanistan :-(
Did you get your helium hotspots yet? Was hoping to see how you power them and also maybe even provide some Spiess solution for internet coverage. Thanks for awesome content as always. :)
I never ordered Helium Hotspots
@@AndreasSpiess Then i misunderstood another video. Apologies.
@@chioz Andreas was sarcastic in that video. Helium seems to be a scam. Watch that video again.
@@eugy2008 oh, i didnt get that. got a few on the way anyway. I think If poeple get roi pretty fast, it should not matter if is a scam as long as it works. And looking how the neighbours are earning I think it ok.
Looking forward to adding sensors to the helium network myself by the way.
I love making things works, so when i some day have the time, i hope andreas videos is avalable for me to make more serious use of it.
But I seriously dont understand why some say it is a scam...
Grüezi Andreas ^^ Immer wieder enttäuschend zu hören, dass von etwas Spannenden nichts wirklich am Markt existiert. Vl. wärst genau du der Richtige dafür sowas zu entwerfen und auf den Markt zu bringen :D KiCad ist ja gratis & services wie JLCPCB können günstig Platinen in "Massen" herstellen. Würde mich freuen einen eigenen Shop von dir zu sehen :)
Als ich jung war habe ich HW verkauft. Heute ist dieses Geschäft so uninteressant dass ich ich die Finger davon lasse. Ich habe es ja nochmals mit dem "Super Power Projekt" versucht und bin wegen der Chipknappheit wieder auf die Schnauze gefallen :-(
EEPROM and Flash are different technologies. The number of write cycles for an EEPROM should be well above a flash memory. But still some wear is to be expected.
You are right. Unfortunately, the ESP32 emulates EEPROM in flash (I did not want to explain it here)
Very informative, as always! I was wondering how worse off one would be with a solar USB power bank? They tend to be very cheap, robust and just a matter of plugging them in via USB. What’s the breaking point in terms of cost/performance compared with a DIY panel+battery+electronics?
Mine stops delivering power as soon as it charges. I even thought it is defective. So pay attention if you buy one.
Hi Andreas, I learn a lot each time I watch your videos. However this time I was surprised by the advice to use disposable batteries, these causes environmental issues and I guess we would be better off using 18650 that can be changed then recharged for later use. I've been trying to eliminate as much as possible the use of AA or AAA batteries at home when I realised the pile or difficult to recycle batteries I was generating. in addition the rechargeable version of those are not very good.
I suppose depends on the area - in some places disposable batteries are easier to recycle than others. Anywhere that you can recycle one you can probably recycle the other.
I propose primary batteries only for applications where they live for a year or longer. So I do not see big problems compared to all other waste we produce. For the other scenarios I propose rechargeable batteries.
Txs for this video as it's very timely. I'm building a water level sensor (SR-HC04) for a water tank and want to go the battery operated route if possible. Initially my thoughts were deep sleep and automatically wake up a few times a day to send the water level. However in discussions with my neighbor he would want to see the level at a particular time (i.e. use case #5). Also what's the difference between use case #3 "battery operated and don't sleep at all" and use case #4 "on 24/7"? Is it possible to have an event driven use case (without a physical switch/relay etc.) and get a few months of usage without needing a Tesla battery wall :)? How do I go about dimensioning the battery requirement? Love your videos!
If you use a properly designed setup and deep sleep you can get a few month life. But pay attention to ultrasonic sensors, You also have to switch them completely off during deep sleep. So you need a custom-designed diagram probably using an ESP32-WROOM module plus a FET to switch the sensor (use case 4). Use case 3 does not work for a long time because they are always on.
@Andreas Spiess Not quite sure what this is about...
Also, my Two AA batteries have survived 3 Canadian winters.
Very good to know. Thanks!
Hi Andreas,
Thank you for another great video. In 11:45, you mention the p-channel mosfet solution you proposed in video 101 is not reliable. What are the exact issues one can encounter? I was just about to build that for an arduino circuit. Thanks!
It heavily depends on the voltage levels and the Vgs voltage of the FET. Buit you can try. If it works, it is ok.
Thank you @@AndreasSpiess. I built it with just a p-channel mosfet, and tried (Arduino Uno, with NDP6020P or IRF4905PBF), it did not work.
With the new circuit you showed in this video it did. Thank you!
Hi, great video. Have you a video in which you comment the problems about "only one mosfet" and why you change to the two mosfet version? Or could you comment ? Thanks.
The one mosfet version depends a lot on the Vgs voltage vs the battery voltage and you need a FET with a very low Vgs.
@@AndreasSpiess thanks a lot
Hi Andreas, Did you ever try PKcell 3.6v as a battery supply without any regulator so you will avoid quiescent current as well
What chemistry does it use?
@@AndreasSpiess Lithium but you need a supercapacitor for rush current
Regarding OLED display pinout: It seems "impossible" to know the Vcc/GND pinout on those OLEDs. I have ended up making solderbridges on my PCBs to select Vcc & GND.
AFAIK they sell these small ones in 2 versions. Becaus I know the issue I pay attention (and have a few of each version in my drawer). But solder bridges are also a good idea.
@@AndreasSpiess Yes there are both versions, but my experience is that it does not help studying the Aliex ad. On the positive side, I get a partial refund when the delivered differs from photos. ;-)
Choosing right LDO for solar powered, deep sleep project is very important. Why HT7333 and not ME6211? What is your experience with these two?
I never worked with the ME6211 and the board with one of the lowest deep sleep current in my test used an HT7333… Maybe somebody else has more information?
For HT7333 the max. quiescent current (the one you have even without a load - the one you care about in the deep sleep) is 7 uA. For ME6211 it's 60 uA (looking at the datasheet). (other sources say it's 4 uA vs 40 uA). Still it's 10 times more current (energy) drawn by the LDO during the sleep time - something that makes HT7333 vs ME6211 choice rather obvious :).
For example the ESP32 processor lowest deep sleep current is 10 uA. It doesn't take the other things (like the crystal) into account - but still for my board the HT7333 + ESP32 (WROOM32D module) when they sleep, together they consume around 50 uA - still lower than the ME6211 alone :). Doubling that with ME6211 would make the device last 2x shorter on the battery..
While looking at specs, HT7333 may not provide sufficient peak current (250 mA max vs 500 mA min required for ESP32-S2). Same check for ME6211 gives 500 mA max that sounds good. Not sure what a block consumes so much power inside ESP32-S2, maybe Wi-Fi (~310 mA peak) plus something else? In no RF mode chip takes mere 19 mA max, so HT7333 fits here well. Do you know other LDO's for 500 mA?
@@NikolaiVarankine Sorry for late reply. I won’t touch any LDO supplying less than 500mA when using WiFi etc. in a project. May be bulk capacitor can used to cover spikes in current demands.
Sometime ago I saw a list of LDOs somewhere. I haven’t verified all the data. But it seems a good spot to begin when choosing LDO. Here is that list.
LDOs (Low power dropout regulators)
MAX1724:
Range voltage: 0.91 - 5.5 V
Max current out: 150mA
Quiescent current: 1.5 uA
Drop out voltage:
MCP1700:
Range voltage: 6 V Max
Max current out: 250 mA
Quiescent current: 1.6 uA
Drop out voltage: 178 mV
Ht7333:
Range voltage: 12 v
Max current out: 250 mA
Quiescent current: 4 uA
Drop out voltage: 170 mV
HT7833:
Range voltage: 8 v Max
Max current out: 500 mA
Quiescent current: 4 uA
Drop out voltage: 360 - 500 mV
MCP1825:
Range voltage: 6 v Max
Max current out: 500 mA
Quiescent current: 120 - 220 uA
Drop out voltage: 210 - 350 mV
XC6203(XC6203E33):
Range voltage: 8 v Max
Max current out: 400 mA
Quiescent current: 8 uA
Drop out voltage: 300 mV
ISL91107IR:
Range voltage: 1.8 V to 5.5 V
Max current out: 2A
Quiescent current: 45 uA
Drop out voltage: Buck-Boost 96% efficiency
TPS73633:
Range voltage: 5.5 V
Max current out: 400 mA
Quiescent current: 10 mA???
Drop out voltage: 75 - 200 mV
AP2112:
Range voltage: 6 v Max
Max current out: 600 mA
Quiescent current: 55 uA
Drop out voltage: 250 mV
RT9013:
Range voltage: 5.5 v Max
Max current out: 500 mA
Quiescent current: 25 uA
Drop out voltage: 250 mV
AAT1217:
Range voltage: 6 V
Max current out: 600 mA
Quiescent current: 300 - 500 uA
Drop out voltage: stepup 93% efficiency
TLV73333:
Range voltage: 5.5 v Max
Max current out: 300 mA
Quiescent current: 34 uA
Drop out voltage: 150 mV
LM2936:
Range voltage: 5.5 V to 40 V
Max current out: 250 mA
Quiescent current: 20 uA
Drop out voltage: 400 mV
TC1262:
Range voltage: 6 V
Max current out: 500 mA
Quiescent current: 130 uA
Drop out voltage: 650 mV
SPX3819:
Range voltage: 16 V Max
Max current out: 500 mA
Quiescent current: 8 uA
Drop out voltage: 550 mV
AMS1117:
Range voltage: 12 v Max
Max current out: 1 A
Quiescent current: 5 mA
Drop out voltage: 1.3 V
Hope its helpful.
@@zenzeni77 Thank you very much!
One use case missing here is the combination of any of this and use of LoRa since that's a whole new can of worms.
You find many videos on LoRa on this channel...
I have a question for the big brain people 😜. What development board do you suggest for me to start with? My 9 & 11 year old son's want to get into IoT and automate our motorHOME. Since we live in it full time, we want to have fun AND protect ourselves with gas detection, water detection, and fun stuff. I have an Arduino and a raspberry pi, but it seems like it will get WAY too expensive to use those for every project. I know very little knowledge, will be learning with my kids and using a LOT of tutorials. We will eventually be off grid, completely and only using our 24v solar system. Thanks!!!
Most of us use Chinese boards with either ESP32 or ESP8266 chips because they offer WiFi and the ESP32 Bluetooth. And a Raspberry as a server. Then the price is not too high.
You find many videos on this channel where I compare the different boards. I would always start with the needs in mind. There is no "one size fits all" board
Hello, great videos.
Do you have a video or suggestion for powering 6 esp32 boards with a single power supply?
No.
Hi Andreas, thank you so much for this video. Where can I buy the transparent box you have used to store your circuits powered by solar boards?
Thanks!
I had them from ikea. But the base did only survive one winter.
@@AndreasSpiessthank you!
Bedankt
Thank you for your support!
Why LDO? I think that buck is much better, S-8551, for example (C140908 on lcsc), XC9236A33CMR (C122892) and some else.
I do not use buck converters for such small voltage differences. Too complicated (and always the risk of RFI). For bigger voltage differences I also use switchers because the LDOs get hot and waste energy.
@@AndreasSpiess I tred solution with XC9236A33CMR buck, it works with ESP8266 down to 3.35 volts on the battery (it do about 3.25 volts on the ESP). With S-8550 (8551 have different pinout) I will try soon.
Hello Andreas, @2:24 you mention that you power the unit by soldering the wires directly to the board. As an electronics fumbler, I would like to know more. Which pins and at what voltage do you solder the wires to? I don't want to use the USB connection if possible.
The pins on these boards are marked (usually 3.3 or 5 volts)
I tried everything to get a power supply with no noise for a seismic sensor design of our company back in 1987.
After weeks of research and testing, I ended up using batteries. Everything else was just too damn noisy.
A power supply designs are dictated by their use. Sometimes you can get away with a simple LDO.
However, sometimes there is no solution but to use batteries.
You are right. I also tend towards batteries if noise is an issue. To "characterize" a power supply for my radios I compared the noise with a battery, with a server power supply, and with ferrite beads included. The battery sets the reference...
very good video thank you! was also just wondering where is the flow chart as cannot seem to find it yet
Sorry. I forgot the link. Now it should be there: drive.google.com/file/d/1oJCdEHmf03SkHnGSDLGGOvvTDBBSBPix/view?usp=sharing
suggestion for andreas to include timestamps in the videos
Most of my videos are not good for timestamps because later content depends on earlier content.
👏👏👏
:-)
Concerning power-supplies and Meshtastic, I see your recent 2021-09-05 video on power
supplies. Being in the (periodically) cold north, it would be nice to
power this with super-capacitors with no batteries. I've seen some
videos on this type of circuit, but was wondering whether you'd want to
address it? I'll copy this into your recent video on power supplies.
Maybe I will have a look at it. But only for solar powered devices. Otherwise the caps become very big.
Requesting actual microups test for pi, routers, op etc
Do you have links to those devices?
Which one do you recommend for an ESP32 WROOM? Considering it has a 5 V and a 3,3 V voltage supply pins
Most of the ESP32 boards run on 3.3V (with a 5V regulator to be powered from USB). You should be able to connect 3.3V directly to the 3.3V pin. So you have many different possibilities for powering like mains (via USB), Li-Ion (with a 3.3v regulator or LiFePo4 batteries without a regulator.
Hi, using the ttgo t-call esp32 sim800l have you had problems with the 3.7v lipo battery not cutting in when attached to the JST Connector connector for if the main usb type c 5v goes down. Used as a back up battery? Regards
I do not own such a board :-(
That smiley emoji was so creppy my god.
Thank you for your feedback. It helps to improve the channel!
Do you use a specific brand of usb chargers? I'm looking low idle consumption and after some reading it seems like there is quite a variety, even in products from the same manufacturer.
I never looked at idle power. I usually use Baseus or Ugreen. But I have no "proof" that they are better.
Regarding data retention, have you considered using F-RAM instead of eeprom or flash?
A few other viewers commented also on those FRAMS. I never used them. So far I had no use case.
Really useful
Thank you!
I wondered if a simple DC self latching relay might be a good choice to switch directly to the battery after the initial battery voltage falls. There's no voltage drop or power required to hold it after it's pulsed open or reverse pulsed closed. There seem to be a lot of these "bi-stable" flip flop relays available are there any really tiny ones? Maybe that's already been the discussion, I'm slow sometimes. Of course there's probably going to be a big spike on the supply voltage...
This concept has to be proven. You get small bistable relays
Hello Andreas,
I am new to the world of microcontrollers and micropython. I use a ESP8266 dev kit on a breadboard. The ESP is powered by the (micro-)USB connection to the computer, necessary for coding and executing Python scripts on the ESP. For additional devices, I use a power supply module on the breadboard which provides 5V and 3.3V. Question: do I have to connect 5V or 3.3V from the breadboard power supply to the respective pins on the ESP dev kit? Thank you for your very informative videos. Regards.
No, You do not need to connect them in your scenario. The 4V pin can be used if you do not want to use USB to power the board. And 3.3V is an output.
4:18 I want to make a battery powdered project using ESP32-S3 which is going to use a 4.2V Lipo as power source. The project is also going use 10 LEDs. The ESP32 with WiFi is going to be powered for around 5 minutes at a time and then go back to deep sleep.
Question: Between the Battery and ESP32, should I use the HT7333 Voltage Regulator(250ma max output), or should I use another Voltage regulator like AMS1117?
The HT7333 should be ok for an ESP32. Always include a 10uF capacitor across 3.3 and GND of the ESP.
@@AndreasSpiess Thank you
Thank you ♥
I want to use ESP32 in my car for long time , so how to power it from car battery ? (forget about cigarette lighter)
You get small buck converters for that voltage range. And do not forget the fuse ;-)
Thank you❤️
yay good information
Glad you think so!
I want to build a clock with a lot of LEDs. Since it draws a lot of current it and is on 24/7 it should be wall powered. But the voltages that the addressable LEDs need is usually different from most dev boards. How to keep it simple and also not too hot?
I made a video on how to work with Neopixels
Hi, if the battery must be rechargeable below 0°C use Lithium Titanate (LTO) cells (-20°C).
I've been locking at those for my project. Interestingly, only the large LTO batteries seem to have those low temperature charging capabilities. The small, AA size do not, at least from my research on aliexpress. Let us know if you find different info.
Hi, get the datasheet of this cells (scroll a little) : says for LTO1865 - 15°C for charging. Hope it helps.
shop.gwl.eu/LTO-technology/Pack-of-5pcs-LTO1865-Rechargeable-Cell-2-4V-1300-mAh-Lithium-Titanate.html?force_sid=0qra68almb5ma1i1k3mdas3718
The problem of LTO batteries is that you do not get a lot of chargers or protection circuits. In addition, you need 2 in series to get to the needed 3.3 volts. But of course, in harsh conditions, it might be a good solution.
@@ragohy Thanks. It does help!
Hello Andreas, where can I find more info on temp & humidity sensor you show at 1:45? Is it ESP powered? Thanks.
I had it from Aliexpress (Xiaomi)
like than watch :D haha Thnx Andreas :)
You are welcome!
The HT7333 maximum current is ony 190mA, how that works when using Wifi?
I'm guessing 'recommended' capacitor to give enough tank for the short duration pulses wifi would consume.
@@frollard 10uF would be enough? I don´t think so
The size of the capacitor does not matter too much (as my tests show). The current peaks are very short and it seems the HT7333 can deal with it. Average cuttend consumption of an ESP32 is only around 100mA
I'm trying to power an ESP32 with 2 AA alcaline batteries and using a step up DC-DC (MT3608) to make it to 5V. The red led blinks all the time non stop.
This setup works for the NodeMCU ESP8266.
It also works using a simple phone charger.
Any ideas?
Maybe you consult the diagram of your board to understand what the LED is used for. There are many different boards around.
@@AndreasSpiess I found out its a problem with the current, low batteries. I don't know what is the DC-DC doing then...