How a Smartphone Knows Up from Down (accelerometer)

How a Smartphone Knows Up from Down (accelerometer)

Bill takes apart a smartphone and explains how its accelerometer works. He also shares the essential idea underlying the MEMS production of these devices.This video is based on a chapter from the EngineerGuy team’s latest book Eight Amazing Engineering Stories (Learn more at

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49 Responses to How a Smartphone Knows Up from Down (accelerometer)

  1. Jeffrey314159 says:

    Accelerometers in ICBMs, and car’s airbag release mechanisms use a mechanical device called a Rolomite, invented at Sandia Labs in the 60’s.

  2. Bradley says:

    Im disappointed i thought maybe it was truely solid state and detected gravity particles.

  3. SIStefanov says:

    How does it detect movements in the other two directions? Does the phone has two more chips? or am I missing something?

  4. I. Wyrd says:

    Brain explodey

  5. Tjita1 says:

    How do solid state gyros work, then? Is it just accelerometers placed in a circle?

  6. Guitar Guy says:

    It’s too complicated to understand but I loved it

  7. Nemo7The7Pirate7 says:

    That visualization is incredibly poor in connecting the motion of a phone with corresponding operation of accelerometer.

  8. RMJ1984 says:

    And to think that some day in the future, someone is gonna look back, just like we do now. And make a joke about how big, clunky and inferior the phones and their parts are.

    It makes me wonder just how much smaller they can make stuff.

  9. thebowlzack says:

    he answers questions that I didnt even know I had. Brilliant videos

  10. Corey Walsh says:

    yer awesome dude! thanks for this video luke skywalker

  11. pyrokazama says:

    I liked accelerometers, but damn it knowing the science behind it makes them beyond amazing, this kind of tech blows my mind.

  12. ETgoHome says:

    Lol he used a motorola

  13. James Nguyen says:

    Imagine bringing this to someone in the 1700s. The smartphone would blow their minds. A tiny handheld box, outputs moving pictures, sounds, captures pictures, can detect light, knows which way is down, and can do math. *Mind Blow*

  14. Kees Worteldijk says:

    I like your hair!

  15. mrsemifixit says:

    Can someone explain the difference between this and a gyroscope?

  16. The Woodys Surf Instrumental Band says:

    I know how to make a peanut butter and jelly sandwich.

  17. Dingus says:

    Just discovered these videos today, holy shit I could watch these forever

  18. Christian O. Holz says:

    Great narration and method of explanation

  19. Christopher Thatch says:

    Can you explain why note 7 is a bomb in disguise

  20. Ariel Lázzari says:

    Who the fuck downvotes something like this?

  21. Tynan Roussety says:

    hypothetically – Using an accelerometer, could you measure the number of revolutions the phone did if it was stuck to a fan blade?

  22. EVAN_ 3301 says:

    meanwhile people are burning phones to get views on YouTube

  23. maxwell,cpp says:

    so this accelerometer won’t function properly if a force opposite to gravity is applied..

  24. Brian Wittling says:

    and yet somehow, we still don’t force people to record video HORIZONTALLY on their gorram phones!

  25. Massive Munch says:

    Try saying accelerometer 10 times quickly in a row n see what happens. You can feel your consciousness slip away and enter a different realm.

  26. Ray Maritz says:

    You learn something new every day! Too bad I’ll be dead in two or three decades from now and never experience where this ride is taking us. … then again, that might be a blessing.

  27. AtomicRobot says:

    Is that bill’s phone number? 217-689-1461 @ 0:10

  28. maxisan137 says:

    But how do they make the coating with holes or patterns that small?

  29. PJ Avinash says:

    love the way you explain the things..

  30. David McDonald says:

    "0:27" you are pointing to a capacitor, the accelerometer is to the left.

  31. Bradley says:

    It wont work in space

  32. Prince XVII says:

    So how does the orientation lock work?

  33. BlackQueenNetwork says:

    people believe this was designed but think the human body evolved, lmao

  34. Taky says:

    Now explain why viral videos are shot in vertical

  35. Francois Deshue says:

    wonder if they could have used waterbears, living inside a tiny capsule.
    i think bio material science is the future, using microbes and microscopic creatures to make super computers. like a society based on slavery of the masses, trading fake paper currency and basing their lives on useless consumerism while drowning on their own refuse.
    ohh wait….

  36. Shubham Gupta says:

    Can someone tell more about how the current flows between differential capacitor?

  37. Harsh Kumar Narula says:

    thank you so much

  38. Júlio Tironi says:

    Really appreciate your work man

  39. fla playa says:

    From steam engines and horses to… Well… Today.
    Insanity at the very least to out of this world at the most.

  40. zachary paris says:

    dude blows my mind every time.

  41. George Kariuki says:

    so the entire accelerometer depends on mechanical movement and people thought smartphones were so advanced

  42. عراقي عاطل عن العمل says:

    Can you explain to us about the sensor in the Galaxy?

  43. Eli Suryana says:

    lol imagine having to make the accelerometer with great precision, must have been a difficult time trying to make the accelerometer. at only 500 micrometers big the robots must have really incredible precision just to etch the silicon.

  44. Kaarel Kahu says:

    But why use three pairs of combs all for one direction?

  45. WheeledWanderer says:

    Engineerguy for President…

  46. heyzeus023 says:

    Thanks, capitalism.

    RIP Marx lol

  47. Oh Fudge says:

    Accelerometers can also be used to determine your position relative to a start point using the fact that your position vector is the double integral of your acceleration vector (and your velocity vector is obtained from integrating you acceleration vector once).

  48. beshj says:

    (((S I L I C O N)))

  49. AlmightyDemon says:

    Incredible video series. The explanation is so good and on point.