Unresponsive Limit Switches

[nathanww]

Did you check the switches with a multimeter, and if so are they actually changing values when you press them?

[Kahn!]

We blew out the DIO channels on our sidecar last night, though the rest of the sidecar still worked. Try hooking up your second digital sidecar; you may have a similar problem.

[daltore]

This may seem like a stupid suggestion, but are you 100% sure that the limit switches are being pressed? Sometimes they can look pressed but not be contacting, especially if you're using the turret itself to activate them.

The VEX limit switches are SPDT type (single pole, double throw) meaning that there is a common line that is switched between the two other lines. I believe the common line is the signal (white) and it switches between ground and +5v, but don't quote me on that. I know that the closed state of the switch connects ground to signal. Just make sure all the wires are going to the right places for the digital sidecar, as these switches were designed for the VEX microcontroller, which has all of the DIO pins pulled high, so the configuration may be different.

Edit: The SPDT function is unused, signal is attached to the NO (normally open) pin and ground is attached to C (common). This means the circuit is closed between signal and ground when the switch is pressed.