5 cent tilt sensor


This is a 5 cent tilt sensor. We know it cost more than 5 cents, but it is in fact a tilt sensor that utilizes a 5 cent coin. We’ve all done quick hacks to make quick sensors for various projects. We’ve seen tons of them, from stealing springs out of pens and shoving a resistor through them for flexible contact switches, to tin foil touch sensors. This one is new to us though. The design is fairly simple, you insert 4 bits of wire to serve as contacts and the coin will make contact with only two at a time. It isn’t analog, it isn’t extremely precise, but it is super quick and easy. Thanks for sharing [ix].


  1. macegr says:

    Gotta protect the children from all that corrupt tilt. Censor it! (this may not make sense if Caleb eventually edits the article for the correct spelling of “sensor”)

  2. jaded124 says:

    Hmm… All along I thought the tilted censor was Tipper Gore…

  3. hogiewan says:

    @jaded124 – LOL

  4. Caleb Kraft says:

    haha, good eye guys. thanks for the heads up.

  5. mrasmus says:

    Hate to be the barer of bad news… but censor in the first sentence of the body itself is still present. :P just fyi.

  6. ejonesss says:

    cheaper yet use a penny.

    even cheaper use the steel slug from an electrical box.

    just make sure it is not from a box you are going to be using unless you are installing a new line because you dont want to leave a hole in the box that may compromise the emf shielding of the box

  7. Chris_C says:

    Just a thought – but use a smaller disk and a number of them mounted at different angles and you increase the accuracy…

  8. kyoorius says:

    I’m thinking that if you mounted a small fan blowing from underneath you could upgrade it to a frictionless tilt sensor or a mini air hockey table.

  9. macgyver says:

    Look MacGyver series, I don’t remember the exact season and episode, but that one with some crazy guy trying to blow up some school. The BOMB (NSA, CIA and FBI I said B-O-M-B!) had various sensors, one of them was tilt sensor made of mercury between two transparent (optional ;) ) layers and dozen of wires. Fast, cheap and easy to make.

  10. mike c says:

    It ain’t analog……but it is digital!

  11. mike c says:

    another thought….with a whole bunch of wires around it in a circle, it could be more accurate and do more than just left/right and forward/backward.

  12. GianniQ says:

    As cool as this is I want to know about the tin foil touch sensors. I’ve searched but found nothing, any got any links for me.

  13. guy_smiley says:

    two pieces of tinfoil glued to a sheet of cardboard folded over, tape/solder your wire leads to the (isolated) tinfoil then when you press the two side together you make “touch” contact.

  14. falcolas says:

    @macgyver – I remember that episode as well! Fairly ingenious, and it would work, too. The dish would simply have to be slightly concave – the degree of it’s concavity would determine how sensitive it was.

    I need to make one. The switch, not the rest of the device.

  15. djrussell says:

    @macgyver. mercury switches are nothing new. cool, but not new. the sensor here is non-toxic too. :)

  16. xrazorwirex says:

    How smoothly does this reset?
    You would think this would cause ‘perpetual tilt’ problems since nothings keeping the coin centered.

  17. NeilJB says:

    If this sensor is mounted parallel to a cube face, its output will be indeterminate when that face is on the bottom ot top of the cube, i.e. the coin could be touching any pair of wires. If, however, the sensor is mounted at 45 degrees to a face, its output will always be determinate. Therefore, to reliably determine the orientation of a cube at rest, the sensors (two will give a solution) need to be mounted at 45 degrees to two faces, and at 90 degrees to each other.

  18. Tony says:

    This tilt sensor is the lulz but I bet it works alright.

  19. Quin says:

    MacGyver Season 3, Episode 9, Hell Week. Okay, so the real reason I remember is because John Cameron Mitchell was in that episode.

    It’s a neat hack, for anything that just needs a 1 time tilt sensor. I’d worry about the coin reseting back to level when the full device is back at a rest state. Maybe ball bearings and a convex surface? Or at angles to the surface, if it’s a flat cube-like object, like neiljb said.

  20. Ironz says:

    This is a cool concept but not practical in any way when you consider a full blown 3-axis accelerometer can be had for under $5.00 (+/-0.50 for external components)…


    (I know the small pad areas might be hard to solder but with the patience to make the device mentioned, anyone could dead-bug that chip.)

  21. dan says:

    yeah but you probably dont have one of those lying on your desk when you need it

  22. it0 says:

    Perhaps an idea is to attach a spring, like the ones found in a ballpen, to the center of the coin, for it to center back?

  23. Gofo says:

    Maybe a small steel ball could also be used in place of the nickel.

  24. DanS says:

    I have used some nails and a washer before with good results… Pound a nail into a wall. Place the washer onto nail. Put another nail into the wall so that when the washer wobbles it will close the two nails together.

  25. Andrew says:

    Try using a mouseball (take the rubber casing off the metal ball) and a reflector mirror from a flashlight, and voila! This same “hack” + re-centering ability!

  26. Paul says:

    Older pinball machines use a small pendulum with a metal ring around it, if the pendulum swings more than 10* or so it contacts the ring and sets off the tilt alarm, it also self centers as long as the pinball machine is on level ground. These would be fairly easy to make also. And I’m sure you could use a similar 4 wire design instead of a ring if you desired to know the direction of tilt.

  27. jim says:

    Just a thought… a vibrating motor attached to the base and you might be able to Kalman filter the inputs to get analog measurements…

    This is, in fact, how MEMS accelerometers work.

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