Let's Make Robots!

magnetic strip physical feedback

Check this article at hackaday.com The original post was on a myspace-page, but I cant manage to link to the single article

http://hackaday.com/2007/01/21/magnetic-strip-resistor-midi-controller/

They use the resistance in the magnetic strip on a credit card to input data. In this design they use a finger drawn along the black stripe and a stripe of conductive metal tape to produce midi-info for a computer. But could this aproach be usefull in robotmaking? Would it be practical to use for reading the position of a robot arm? any other uses?

I have access to quite a few of these cards from an old security system, so if anybody can think of a worthy experiment, I'll gladly donate a few.

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When I was bout 10, I took out the "head" from a tape-recorder, and took it's output wires into a microphone / amplifier.

At the time, my bank-book had a magnetic strip on it, and I realized that it "played sounds" when I moved the head over it.

When I was teenager, I got a social security-card that had a magnetic strip on it - just like a credit card today. Ire-did the experiment, and this time made sort of amusical instrument; One could "scratch" a plastic card along a piece of cardbord on a box, and make .. sounds :)

Now I am an old fart making robots when time.. and I have of course considered re-doing it. Only, this time, I was considering reel-to-reel-tapes glued onto a track of some sort, and then having the tape-recorder-head pick up the info below the robot..

 

Point is; Get a tape-recorder and an amplifier (say, from some PC-speakers) - hook up to same ground as the microcontroler, and your analouge in could be "listening" to your granmoms voice below it's wheels..

This is a very cool input device - ie speed control - or colour change (dimmer) cant wait to experiment.

One Question :- What happens when the card is flexed?

(i am hope-ing that is gives at least a small change - then there are even more capabilities (ie strain gauge)

Just hooked up my parking card to the meassury thingy, and flexed it. No change in resistance.
All he's done is to use it as a pot. You can make something like that with conductive glue such as the stuff I used in giving your robot a sense of touch.
I guess you're right OddBot, but I like the idea of re-use

Could be useful, in controls as he has done in the video. Maybe in a linear positioner too, like jaws closing on a manipulator.

I wonder though if the cards could be used in their original app, recording data to be played back by a robot. Whaddya think?

so, have cards with info on so that depending on witch one you stick in the robot it would change its actions? sort of like changing thr code just by changing the card and not having to download it from a computer ?

 now that would be cool !!

My kids had a toy a couple of years ago that could be "progreammed" by inserting different cards with mag strips containing instructions. Went in the bin quite soon cos it was boring.