Hey, I have a little project to figure out for my car and thought you guys could help me figure this out. What I need to do is put multiple switches on a steering wheel but the kicker is that I only have one wire to send the signals through the column. To eleborate, I can only use the horn contact because it spins with the steering column.
Ford did this with cruise control functions on the steering wheel and each button had a resistor on it that switched to ground. So say switch one would have 5k ressitance and switch 2 would have 20k resisntance so on and so on. then on the other side of the wheel the module could tell which switch was pressed based on the resistance to ground.
What I need is something just like this that can ground a series of normal automotive type SPST relays and have normal off the shelf miniature NO mom switches on the wheel.
Im sure I could make a fairly simple circuit to do this but I dont have a clue what principle this is based on. Hopefully someone can point me in the right direction. BTW Im hoping to make this with just regular components and no programming or anything like that, just simple robust components that can differentiate the different buttons. Thanks.
Ford did this with cruise control functions on the steering wheel and each button had a resistor on it that switched to ground. So say switch one would have 5k ressitance and switch 2 would have 20k resisntance so on and so on. then on the other side of the wheel the module could tell which switch was pressed based on the resistance to ground.
What I need is something just like this that can ground a series of normal automotive type SPST relays and have normal off the shelf miniature NO mom switches on the wheel.
Im sure I could make a fairly simple circuit to do this but I dont have a clue what principle this is based on. Hopefully someone can point me in the right direction. BTW Im hoping to make this with just regular components and no programming or anything like that, just simple robust components that can differentiate the different buttons. Thanks.