A simplified explanation of how a capacitive MEMS accelerometer works. Website: www.afrotechmods.com/ Accelerometer math: www2.usfirst.org/2005comp/Manu...
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Great job covering some prime electronics topics that hobbyists and engineers are commonly looking up! I love the channel; everything you say is well thought out.
I found you after looking up some scientific glassblowing videos, and I have to say this is one of the best channels on UA-cam. I wish my recommendations had videos like this instead of Vevo and Veritasium.
You set me straight, as I thought they had something like an Inclinometer or an encoder that has a small weight on it. PS: Another great video, can't wait for the next one.
keep up the great videos, your videos help me so much, and i have relied on them to understand quite a bit of what i currently know about electronics, hope i can be as successful one day.
What I wonder with these micosystems is HOW do they actually move? Are they suspended in some medium? Where are the fulcrim points? And how long is the mean time between failure? Will my car with 100,000 miles hav .one fail and wrap me in my big Pie Hole someday? Can you do a.video on barometric swotches also, and others on these most interesting devices? Do.these qualify aa nanomachines?
Some animation would help the viewers tremendously in visualizing and understanding what you are talking about. I, for one, are still not quite understanding what you are trying to convey.
Change in distance between closely spaced conductors will alter the capacitance between the conductors. Look at the comb structure just as two plates for simplicity. the two plates are separated by an air gap dictated by the manufacturing process. At any rate it is a very small gap. Due to inertia ( things wanting to stay at the same speed they are currently going)when the system moves the weight wants to stay in its current state more than the thin plate(s) it is attached to so in doing so it bends the plate ( or comb) it is attached to creating a difference in capacitance which is sensed electronically.Is this helpful?
Great video! I've read that acclerometers are very noisy and should only be used for steady-state tilt information only, even though they are often rated to measure 10khz. Is this true? Is a gyro the only way to get accurate real-time acceleration data? A video suggestion : the mechanism behind gyros and the practical difference in the data produced vs accerometers!
You can use an accelerometer to measure acceleration just fine. However one problem that some people encounter is trying to integrate acceleration to get velocity or position data, and in those scenarios accelerometer error does accumulate very quickly, so people tend to combine data with gyro & gps.
This was a long time ago, in a galaxy far far away. The technique is called photolithography and here is a good primer: ua-cam.com/video/1bxf9QRVesQ/v-deo.html
+MrPolymath0 There'are a lot of phases as following: - Chemical Vapor Depositation ( at low pressures and high temperatures) o Epitaxial Growth - Etching of silicon parts in order to achieve the correct mass for the wanted resonance frequency ( taking into account non idealities due to under/over etching) --> Dry etching or wet etching - Dioxide Silicon Elimination using acids like HF. So in this way, it's possible to correctly obtain a moving mass which will be the inertial mass for the inertial forces detection. -Packaging ( at low pressure, obviously depending on requirements and budget), by means glass frit or eutectic bonding. etc etc. It may seem easy but it's far from it.
Is there a way to avoid (physical) oscillations in such circuits? Is it damped out somehow? It might be fun to try to make a more macro size one with little magnets on plastic tabs with hall effect sensors.
Since the structures are so small their resonant frequency (and hence oscillations) are very high in frequency, and your measurements would be lower than the resonant frequency. If you do hit resonance, it can destroy the accelerometer though, depending on the model. Some may have a 'hard stop' which prevents excessive deflection at resonance, and prevents damage from mechanical shock (i.e. 8 g accelerometers that can survive a 10,000 g shock)
Strange. For some reason in my mind I always imagined tiny ball bearings in channels with contact points on the the sides and ass the ball rolled past it would tell the device which way it was tilting. I guess it wouldn't be able to detect how many g-forces are being applied though.
Hey Afrotechmods plz do a video that tells the difference between current and voltage... Most of the people in real life doesn't differ between them.. I also do have a little idea about it...
shubham saxena You can think of electricity like a river flowing downhill. The current is the cross sectional area of the river, so is the amount of water flowing at any given time. The voltage (also known as potential difference) is the difference in height of the river, so it is the amount of 'pushing force' behind the river's movement. To sum it up, the current is the amount of electrons moving while the voltage is the amount of force that is 'pushing' the electrons.
Dudes always be like "Damn imagine if aliens came to earth and saw our technology they'd think we're cavemen" when likely they're just gonna be better suited for space travel than humans and the second they look at our technology they're gonna think "holy shit these dudes are fucking cracked"
interesting! How hard do you have to shake an accelerometer for the capacitor plates to touch each other and create a short (possibly destroying the IC)?
Im trying to make a device to help my friend walk straight by sending alerts if slightly deviated (right or left). Would Gyroscope or accelerometer or gyroscope work? I need suggestions. Thank You
It's not the sensor , but the electronics and software that reads it that causes the delay. The data from the sensor is converted to digital data. Then it goes through software calculations to determine the angle , speed .. This causes a delay.
Great video (as always). But I except it to be a little longer. What about making a second part explaining MEMS gyroscope, magnometer, ... (9 dof) and how to use them together to retrieve stable and precise orientation (kalman filter, high/low pass filters...). No need to go in math detail, just to mention it.
The gyroscope uses the Coriolis effect combined with vibrating matrices at each axis. Basically the vibrations tend to stay in the same plane as the supporting structure of the proof mass. IIRC they still use changing capacitance but its the error of the vibrations which is really measured as this would indicated rotation about that axis.
i guess that the reason is because some devices only have data lines with 3.3v volts like the Rpi, if you used 5v you will end up frying the gpio or the processor of the pi
Hi I have a doubt what happens to output of accelerometer when accelerometer is moved with same speed for some time will it be zeros or some constant km/s^2
Afrotechmods thanks for the swift reply, I'm sure you could have mentioned other vendors, it just seemed a teeny bit suspicous, with all the stuff going on and all, sorry for the nagging, fun video! :)
Adafruit is the boss! Why would product placement be bad? Would that somehow reduce afrotechmods integrity? How is getting paid for hard work bad? Do you do all your work for free? I HOPE Adafruit pays him for product placement, so he has more incentive to make rediculamously fantawesomic videos!
Afrotechmods CQ(seekyou?) would be more appropriate for an intro , QRT( basically the end of transmission) for the exit. BTW i watched enineeringuy's video on the topic last week, you both explainit well, but you had the die to show us
That's just an electrical motor with an off-centre mass, like a tiny version of a washing machine with a heavy load, as it spins it shakes. Cellphones have ones that are even tinier still, hard to even recognise them as motors.
No. The accelerometers are used to detect orientation. The Gyros give a turning "rate", which is really not very useful to detecting screen orientation by gravity.
Interested in learning about wireless power? Subscribers can get up to 80% off my course Wireless Power to the People - Wireless Charging 101 on udemy using the coupon code "UA-cam"
www.udemy.com/wireless-power-to-the-people-wireless-charging-101/?couponCode=UA-cam
Qâaw14tt jşüçşşçöççççişiüğğüüiiiiçççççç.ö ç ipiydi bu da güzel 6ı¹²2
Please make more youtube or udemy videos.
This is just what I needed with my morning coffee! KNOWLEDGE!
Great job covering some prime electronics topics that hobbyists and engineers are commonly looking up! I love the channel; everything you say is well thought out.
I really had no idea how MEMS products worked. Great video. Thanks.
Thanks again! My friends and I always learn a lot from your videos. Been following your site for possibly a decade!
I can't like this enough! I really never miss your videos. You are the man!
I found you after looking up some scientific glassblowing videos, and I have to say this is one of the best channels on UA-cam. I wish my recommendations had videos like this instead of Vevo and Veritasium.
great video even 8 years later
You set me straight, as I thought they had something like an Inclinometer
or an encoder that has a small weight on it.
PS: Another great video, can't wait for the next one.
Always great content. Will you make any more videos on MEMS in the future? Very fascinating stuff.
Awesome video Afro!
Great explanation, straight to the point
Groovy information and video dude!
Great video of something that I have always wonder about, but forget to look up.
Wow that video finally manages to solve my mystery about how do they put resistors in ic's
thank you so much for the video! Was very educative and easy to understand :)
Ah!.... Afrotecmods- I did not see that at first- no wonder it was such a fantastic video :)
keep up the great videos, your videos help me so much, and i have relied on them to understand quite a bit of what i currently know about electronics, hope i can be as successful one day.
Thank you so much. It was interesting and very explanatory!
Excellent video! You have earned a subscriber!
Very informative as always, thanks
"That'll buff right out."
Hilarious!
Nice Video, great work, I'm here by GreatScott
Your videos are the boss!
Accelerometers are also used for rifle barrel tuning to get the best possible harmonics for long range accuracy.
Thank you for enabling my study tangent!
What I wonder with these micosystems is HOW do they actually move? Are they suspended in some medium? Where are the fulcrim points? And how long is the mean time between failure? Will my car with 100,000 miles hav .one fail and wrap me in my big Pie Hole someday? Can you do a.video on barometric swotches also, and others on these most interesting devices? Do.these qualify aa nanomachines?
Great stuff, thank you good sir.
Some animation would help the viewers tremendously in visualizing and understanding what you are talking about. I, for one, are still not quite understanding what you are trying to convey.
Change in distance between closely spaced conductors will alter the capacitance between the conductors. Look at the comb structure just as two plates for simplicity. the two plates are separated by an air gap dictated by the manufacturing process. At any rate it is a very small gap. Due to inertia ( things wanting to stay at the same speed they are currently going)when the system moves the weight wants to stay in its current state more than the thin plate(s) it is attached to so in doing so it bends the plate ( or comb) it is attached to creating a difference in capacitance which is sensed electronically.Is this helpful?
amazing video , keep up going
Thank you soooooooooo much. You are a wonderful man.
ok it was really interesting to get this topic understand
not like in the boring class
Yup, definitely reverse engineered space alien technology. lol
lol
😂😂😂
That was really interesting! So, does a 3-axis accelerometer have 3 such MEMS capacitors oriented in along 3-axes?
I'd love to see you make a video on etching silicon like that.. You mentioned it like it was nothing
Excellent video as usual, but how did you create the die circuit for the accelerometer on silicon ?
This is fascinating. Pretty awesome :)
thx so much dude! :) merry christmas! ☻☺☻☺☻
great video, Thanks
What a sophisticated idea! Humans are wild lol
Yes, well. How do you separate the moving part from the substrate?
Great, Love this
thanks for your video
muy buen apunte
And how does it knows the direction? I think the capacitance changes the same way when you push the moving part upwards or downwards.
wooow thank you great informations
Great video! I've read that acclerometers are very noisy and should only be used for steady-state tilt information only, even though they are often rated to measure 10khz. Is this true? Is a gyro the only way to get accurate real-time acceleration data? A video suggestion : the mechanism behind gyros and the practical difference in the data produced vs accerometers!
You can use an accelerometer to measure acceleration just fine. However one problem that some people encounter is trying to integrate acceleration to get velocity or position data, and in those scenarios accelerometer error does accumulate very quickly, so people tend to combine data with gyro & gps.
Can you do a video on touch screens old and new?
If the distance between the plates from the capacitor changes mechanically due to acceleration how is it ensured that they never touch?
Hehe, great that you used a die shot of an IDT WinChip by Pauli Rautakorpi :P
How about the accuracy? Can it be used as Inertial Navigation System
The electricity sound from the patreon logo sounded like DXing in Morse code.
What's the difference with gyroscope like the HMC5883L? Since they both have x,y,z values.
GreatScott!!!!!!!!!!
2:33 METU ❤️
where did you get the silicon? and how did you etch it?
I am wondering the same thing!
This was a long time ago, in a galaxy far far away. The technique is called photolithography and here is a good primer: ua-cam.com/video/1bxf9QRVesQ/v-deo.html
+MrPolymath0 There'are a lot of phases as following:
- Chemical Vapor Depositation ( at low pressures and high temperatures) o Epitaxial Growth
- Etching of silicon parts in order to achieve the correct mass for the wanted resonance frequency ( taking into account non idealities due to under/over etching) --> Dry etching or wet etching
- Dioxide Silicon Elimination using acids like HF.
So in this way, it's possible to correctly obtain a moving mass which will be the inertial mass for the inertial forces detection.
-Packaging ( at low pressure, obviously depending on requirements and budget), by means glass frit or eutectic bonding. etc etc. It may seem easy but it's far from it.
Brilliant.
OH GOD I LOVE MEMES
Oi, I meant 'MEMS'.
😂😂
Hello, from the future
Hello from farther future
Is it possible to use Accelerometer as a motion detector in arduino? I would like to detect human movements, but I am using I2C communication.
MEMES sensor
can accelerometer be used to measure vibration
Is there a way to avoid (physical) oscillations in such circuits? Is it damped out somehow? It might be fun to try to make a more macro size one with little magnets on plastic tabs with hall effect sensors.
Since the structures are so small their resonant frequency (and hence oscillations) are very high in frequency, and your measurements would be lower than the resonant frequency. If you do hit resonance, it can destroy the accelerometer though, depending on the model. Some may have a 'hard stop' which prevents excessive deflection at resonance, and prevents damage from mechanical shock (i.e. 8 g accelerometers that can survive a 10,000 g shock)
Strange. For some reason in my mind I always imagined tiny ball bearings in channels with contact points on the the sides and ass the ball rolled past it would tell the device which way it was tilting. I guess it wouldn't be able to detect how many g-forces are being applied though.
That's called a tilt sensor. Adafruit sells those too. Quick and dirty way for determining "is right side up" or "is not right side up."
Hey Afrotechmods plz do a video that tells the difference between current and voltage...
Most of the people in real life doesn't differ between them..
I also do have a little idea about it...
This much i had since my schooling.
***** wanted to know more.
Thank you though.. *****
shubham saxena You can think of electricity like a river flowing downhill. The current is the cross sectional area of the river, so is the amount of water flowing at any given time.
The voltage (also known as potential difference) is the difference in height of the river, so it is the amount of 'pushing force' behind the river's movement.
To sum it up, the current is the amount of electrons moving while the voltage is the amount of force that is 'pushing' the electrons.
Ben Adamson thank you brother...
Thanx a lot.... 😊😊😊😊😊
It's nice, when it works.
I've always assumed there was a bulb containing mercury or some other liquid metal that would connect different circuits.
Is it possible to create a program that simulates an accelerometer? Such as moving a 3d object around and measuring its proper acceleration?
thx a lot!
Gyro next!
Dudes always be like "Damn imagine if aliens came to earth and saw our technology they'd think we're cavemen" when likely they're just gonna be better suited for space travel than humans and the second they look at our technology they're gonna think "holy shit these dudes are fucking cracked"
interesting! How hard do you have to shake an accelerometer for the capacitor plates to touch each other and create a short (possibly destroying the IC)?
It will depend on the accelerometer. You'll have to check the datasheet. >100g to damage most I am sure.
If they can create solid insulators, via doping, then these can be used as limit stops to prevent shorts
i subscribe u for this owesome video.
BIG like
and what is meaning of combed finger arrangement
Im trying to make a device to help my friend walk straight by sending alerts if slightly deviated (right or left). Would Gyroscope or accelerometer or gyroscope work? I need suggestions. Thank You
Accelerometer would be better but both could be helpful. Look up a device called an IMU (Inertial Measurement Unit)
Do you need a Arduino main board to power the ADXL335 accelerometer?
No you just need a voltage source, but an Arduino would be helpful to read in the data from the accelerometer
Or if you are a games developer you can use Unity for testing the accelerometer ;)
"Here are some dies I made out of silicon"
Casually dropping nuclear bombs
Mems the word!
Hi guys, does anyone know a home built object that a accelerometer can measure?
Please some respond to this.
Why do a lot of accelerometers seem to have a delayed response (e.g. video game controllers, tablets)?
It's not the sensor , but the electronics and software that reads it that causes the delay. The data from the sensor is converted to digital data. Then it goes through software calculations to determine the angle , speed .. This causes a delay.
Engineers are incredible
If I would translate these tutorials to another language, would you like to add them to your videos as subtitles?
ZauStuv Sure!!
My Mamma said magic elves move my screen to the proper position. So your wrong Colonel Sanders.
Nifty
mmm... i think i know my suggestion for the next episode on Patreon.
Great video (as always). But I except it to be a little longer. What about making a second part explaining MEMS gyroscope, magnometer, ... (9 dof) and how to use them together to retrieve stable and precise orientation (kalman filter, high/low pass filters...). No need to go in math detail, just to mention it.
The gyroscope uses the Coriolis effect combined with vibrating matrices at each axis. Basically the vibrations tend to stay in the same plane as the supporting structure of the proof mass. IIRC they still use changing capacitance but its the error of the vibrations which is really measured as this would indicated rotation about that axis.
Is there a reason why so many of these sensors require 3,3V (those who accept 5V very often have a 3, 3V regulator)?
3.3v is a common digital devices voltage. I'm not sure of the origins or reasons it's used, though.
i guess that the reason is because some devices only have data lines with 3.3v volts like the Rpi, if you used 5v you will end up frying the gpio or the processor of the pi
Hi I have a doubt what happens to output of accelerometer when accelerometer is moved with same speed for some time will it be zeros or some constant km/s^2
If the velocity stays the same then the acceleration will be zero. So the accelerometer will read zero g.
@@Afrotechmods But when place an mobile on table it's velocity is zero but the accelerometer output is approximately 9.8m/s^2 in z -axis
@@DurgaPrasad-lp6vb That is because gravity provides a constant downwards acceleration force.
I love smart people!
Next explain how LEDs work
But it won't just buff out Dave! How many times do I have to tell you, dont scratch the silicon.
Are you affiliated with adafruit in any way? just wondering :)
I've bought from them in the past and I find their stuff to be good value for money in general. They had no idea I was making this video.
Afrotechmods thanks for the swift reply, I'm sure you could have mentioned other vendors, it just seemed a teeny bit suspicous, with all the stuff going on and all, sorry for the nagging, fun video! :)
GizmoTheGreen "with all the stuff going on and all" Should I not buy from them?
sashablfc
I think he was just worried I was doing paid product placement without disclosing so. They are fine to buy from.
Adafruit is the boss!
Why would product placement be bad? Would that somehow reduce afrotechmods integrity? How is getting paid for hard work bad? Do you do all your work for free?
I HOPE Adafruit pays him for product placement, so he has more incentive to make rediculamously fantawesomic videos!
what is meaning of (Vin) at 3.14 minute
thank you , but what is combed finger arrangement
It almost sounds like your closing video snippet is Morse code for "CQ". Did you do this on purpose?
Ben Yarmis The outro was created by one of my Patrons who was kind enough to make it for free :) So it was his choice.
Afrotechmods
CQ(seekyou?) would be more appropriate for an intro , QRT( basically the end of transmission) for the exit. BTW i watched enineeringuy's video on the topic last week, you both explainit well, but you had the die to show us
Memes are always the answer
I was imagining a microscopic conductive ball :) inside a container lol
i thought it was like that thing in dualshock that vibrates
That's just an electrical motor with an off-centre mass, like a tiny version of a washing machine with a heavy load, as it spins it shakes. Cellphones have ones that are even tinier still, hard to even recognise them as motors.
Gyro sensors rotate the screen not the accelerometers
No. The accelerometers are used to detect orientation. The Gyros give a turning "rate", which is really not very useful to detecting screen orientation by gravity.
now, how e-gyroscopes work
damn, i thought it has some mercury inside or other conductive liquid to detect movement...