No, not the hall sensor.
This isnt 'really' a sensor at all, its a multi-potistion switch that has a series of resistors in it, depending on what switch is pressed, the current feeds into a different resistor. I said sensor cause it would prolly confuse less people.
The problem is it isnt sending a signal on one wire and reading it on another... Its looks like (I cant get to the hardware of this other processor so I have to guess) that they are outputing 5V and then ADC-ing thier own line.
I need a way of faking the switch. So if it is supposed to hit X resistor and then its own adc reads 3.3V instead of the 5V it would ususally read it know it hit X resistor. If I could sink 3.3V of that 5V so that its adc read 3.3, it would be LIKE the switch with all its resistors is still there, I could mimick this I think.
(I cant make a resistor/transitor hardware path b/c the switch has WAY to many options)