Let's Make Robots!

Multiplexing for my chess robot

Base over Apex showed to me that the "ghost piece" i was talking about could be fixed this way below. 

 Oh yeah i am doing this because my shift registers... well something happened...no im doing this.

This is a common problem. The answer is a diode on every switch. You still need to scan the rows and columns individually.

Here's how to kill the ghost:

diode_open.gif

Make your board with only 16 wires instead of 65.

 

Ok my question is how does a diode on every switch change the "ghost piece" problem?

and on the multiplexing where does the gnd go?

i am using arduino so it has a built in pull down resistor but idk how this darn multiplexing works. 

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Arduino has a built in PULL-UP resistor, there's a big difference. :)
ok what ever. any help with my question?
slap