Single wire, multiple resistance control line.

[svhans]

I was hoping someone can help, I am trying to interface to a switching box that basically has 6 switches and 3 wires. One wire is ground and the other 2 wires break the 6 switches into two groups and each have a 1ohm, 1k and 10k resistor depending on which switch is pressed.

I am unable to get to the switch box to connect directly to the contacts.

I was hoping there was a simple way of using the 2 channels of resistors to drive 6 relays or something similar? or even a PIC I have a few 16F628A's lying around.

Thanks

 

[SABorn]

You will need each resistor / switch to work as a voltage divider and then do a read of the analog value with a pic or picaxe that allows for an ADC to give a digital value for the analog input, then in program its just a matter of switching the correct relay corresponding to the analog value.

This way you could have all 6 channels coming in on one wire if needed, or use 2 wires as you have presently.

Pete.