best Hall sensor for a chess board ?

hello, i am new to this forum and new to arduino. i have done some very light C++programing before, but i now want to make a chess set that works as a "keypad" for a remote opend "safe". so i need to make 5-7 moves in the right order for it to send a signal to a hidden compartment that will then open. i was thinking about using a linear hall sensor for it, and magnets on the chess pieces. is that a good ide ? or is there a batter way to do this ? and what is the easyest way to get it to open the "safe" a second arduino or something els ? and will the programing for this be hard ?
i hope that some one can help me with this,
have a nice day all :slight_smile:

Chrabban:
I was thinking about using a linear hall sensor for it, and magnets on the chess pieces. is that a good idea ? or is there a better way to do this ?

I'm thinking using reed switches will be cheaper and directly give a digital signal (with pull-up resistance provided by e.g. Arduino input). However orientation (rotation angle) of each chess piece would probably be important.

Chrabban:
. . . and what is the easyest way to get it to open the "safe" a second arduino or something else ?

I don't see any need for a second Arduino.

Are you thinking of having an 8 x 8 board? If so you will need to consider how to connect all 64 sensors to your Arduino.

I assume you will not need to be identifying each type of chess piece: king, queen etc.

yes it might be simpler with a reed switches, i was just thinking that you dont hapen to activate it with a magnet on the space to the side of the "real" space. but if i just calibrate them it might be posible so that it only takes the one just on top of it.

at first i was just thinking about getting the middle 4x8, and not identifying the pieces. is there a smart way to identifying the individiual pieces ?

Chrabban:
is there a smart way to identifying the individiual pieces ?

I'm sure that's been asked in the forum before, but I don't recall any details. Have you searched the forum? You should be able to find something under "chess".

okey, well that is nothing that i will be doing right now, right now i whold just want to know what the easyest way to get 5-7 reed switches conected to a arduino and is there something more i need to make it work? as i said before i just want it to use reed switches instead of buttons.

and with what shold i send the "open sesame" signal and to what divice is best for that ? :slight_smile:

will this be a good reed switch ? http://www.ebay.com/itm/2pcs-Normally-Open-Magnetic-Sensor-Reed-Switch-aleph-PS-3150-Perfect-/141541156011?pt=LH_DefaultDomain_0&hash=item20f482a4ab

Take a look at Berger's Solus Chess.

https://sites.google.com/site/bergersprojects/reedcb

Jimmy

I would use hall effect switches rather than linear ones. This project uses them to detect a dice:-
http://www.thebox.myzen.co.uk/Hardware/Dice_Game.html

in what way is a hall effect switch better then a reed switch ? i need this project to be as simple as possible but still work :stuck_out_tongue: i guess that the good thing is that i can set a value that i want on a hall effect sensor for it to be "on" so all the configurations can be done in programing insted of the plasment of the switch. hehe it is hard to know what will be best :stuck_out_tongue:

Chrabban:
in what way is a hall effect switch better then a reed switch ? i need this project to be as simple as possible but still work :stuck_out_tongue: i guess that the good thing is that i can set a value that i want on a hall effect sensor for it to be "on" so all the configurations can be done in programing insted of the plasment of the switch.

Do you actually read the answers? You managed to misunderstand my answer BIG time.

Chrabban:
will this be a good reed switch ? http://www.ebay.com/itm/2pcs-Normally-Open-Magnetic-Sensor-Reed-Switch-aleph-PS-3150-Perfect-/141541156011?pt=LH_DefaultDomain_0&hash=item20f482a4ab

I was thinking of a tiny reed switch such as this example (glass 10mm long):
www.rapidonline.com/electronic-components/minature-spst-reed-switch-60-0520/

However if a small bar magnet is buried horizontally in the base of the chess piece (or pieces) I am concerned, as mentioned, that the reed switch will not operate at all orientations of the chess piece. To avoid this issue, reed switch and magnet could be mounted vertically but the magnet you choose may not be strong enough in that configuration. A unipolar Hall effect switch would therefore seem better, with the magnet mounted vertically (i.e. axially) in the chess piece (and with the appropriate magnetic polarity at the bottom). Another option, could be reed proximity switches such as these:
http://www.rapidonline.com/Electronic-Components/Proximity-Switch-with-Magnet-78-0797.

i know that i you ment the linier one, but archibald game me the tip about reed switches, so if we dont think about the price, what will be the best alternative ?

Chrabban:
i know that i you ment the linier one.

what?

Grumpy_Mike:
I would use hall effect switches rather than linear ones.

I would try these, they seem cheap enough.
http://uk.rs-online.com/web/p/hall-effect-sensor-ics/7512862/

damit i dident update :stuck_out_tongue: so i dident see your awnser. as you say Archibald, a hall sensor might be the way to go. so it shold be posible to mount all the hall sensors and then but on the chess piece on top of it and get a read on it, and set a value that it need to get over to get it as a on ?

Grumpy_Mike, ooh okey, my bad. the one in the link are realy cheap :stuck_out_tongue:

so switch or unipolar Hall effect ? :wink:

so switch or unipolar Hall effect

Is there a choice / difference?

Damit, for a moment i was thinking that the unipolar was a liniar hall sensor, so you both think that it Will be better with a hall switch then a hall linear sensor?

I agree that it will be better to use a Hall effect switch than an analogue sensor (unless you are keen to be able to adjust sensitivity).

Be careful what type you purchase, for example this one is not suitable:
Hall-Effect Sensor - US1881 (Latching) - COM-09312 - SparkFun Electronics because of its "latch" action.

You will need to decide which type of package suits you best. I quite like the look of this one:

but have done very little Googling. See section 10 of its datasheet to see what's meant by "unipolar".

Whether you get false triggering of adjacent sensors (as mentioned in your second post in this thread) will obviously depend on the strength of the magnet chosen, but this is difficult to evaluate. If you get trouble, perhaps you could bury the magnet further up inside the chess piece.

is it harder to adjust sensitivity on a hall effect swith ? yea the latch switch wont be enny good :P.
when it comes to adjusting, wont the linear still be better ? or i might miss something big :stuck_out_tongue: and i can just set it so if the arduino get for exampel 4,3 volts it is get a signal that that spot has ben activated ?
just thinking out loud :slight_smile:
thnx for all the fast awnsers :slight_smile:

Hi,
What is the aim of knowing the location of the chess pieces if you can’t identify each one separately?

Tom… :slight_smile: