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Topic: Digital chess board (Read 3 times) previous topic - next topic

esmo2000

I'm trying to build a chess board which can automatically record a game without any help from the players.  I don't need anything as fancy as actual tags on the pieces (I'm going to figure it out just by dumb dead reckoning), but I'm not sure of the most effective sensors to use for the squares.  Preferably, I'd like the price to be low, but here are some of the ideas I had.

Attach magnets to the bottom of the pieces and lay a grid of wires underneath the board (it's very thin).  When the pieces move up or down off the wires I should see some kind of current induced from the magnetic flux. 

Second idea, was to use magnets in combination with a bunch of reed switches.  This is basically the exact same idea except it's using an actual sensor which is probably going to do a way better job.  The price obviously goes up pretty rapidly though ( I need a reed sensor per square, $1.50 * 64 + 1.50*24 for the magnets). 

Lastly, I could use the FSR sensors listed here: http://www.sparkfun.com/products/9375 but they're obviously a lot more pricey at 6.50 a pop.  Since there are 64 squares, the price is rocketing up to a cool 416 (or somewhere in this ball park).   I considered maybe using square FSR sensors to bring the cost down and having them share squares.  I'm not sure if that would work well.

This is my first time ever building up a full project, and I don't really have any experience with these ideas.  I was hoping you guys could act as a sounding board, maybe come up with some ideas

Jack Christensen

Hall effect sensors come to mind, but would probably be in the same price ballpark as the reed switches.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

robtillaart

- you could also use two motors that "scan" the board with one sensor. you will have 63 *$1.50 for two motors ...
or
- put a small hole in each square and put an photocell under it. - http://www.sparkfun.com/products/9088   64*$1.50  no need for magnets.
Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

esmo2000

Yah I thought of the light sensors as well but I want the board to look as normal as possible with no cuts or perforations or anything.  So cuts in the board I think won't work.

mowcius

#4
Apr 17, 2011, 10:34 pm Last Edit: Apr 17, 2011, 10:37 pm by mowcius Reason: 1
Reed switches for $1.50 each! :o

Try ebay or something - Last time I bought them they were around £1.50 for 10...

Hall effect sensors would be much better though (and still less than $1.50 each).

I used to know a really cheap place to buy neodymium magnets but I can't find/remember it. (They sold the packs of spherical ones and cube ones before they became 'cool toys' and became very expensive items from toy stores - they were really cheap too)

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