3 Way Switches on Driver Station

[finman]

i am trying to wire a few (3-4) 3 way switches (on off on) to the drivers station. what is the best way to to this?

[Dale]

We're using an analog port for three way switches but that's just because we're using most of the digital inputs already.

To use analog ports, the analog input line would need two resistors. The analog line connects to the center pole of the switch with two equal resistors, one pulling it up and one pulling it down.

What most normal people do is connect the center pole of the switch to ground and then connect the poles on either side to two digital inputs.

[eugenebrooks]

New for this year, the driver station does not have pullup resistors
on its digital inputs, you have to include them. We use two digital
inputs for each two way switch, each pulled up to 5 volts with a
10k ohm resistor, and then when the switch is thrown the
corresponding input line gets pulled down to ground.

As noted in an earlier post, you can play games with resistor
dividers on an analog input and get many switch
settings on one input line. Digital inputs are a scarce
resource on the driver station.

Eugene

[Dale]

It is indeed a pain that there are no pull up resistors on the digital inputs. It will work if you just let them float high and then ground them thorugh the switch but that method is more susceptible to noise. This was a big oversight on FIRST's part!