[dtengineering]

While FIRST limits the uses to which a digital output can be put simply to ensure that motors and relays are all hooked up and running in a safe, controlled and easily inspected manner, there is no reason that a digital output can't be used to drive a speed controller, or any number of other uses. We use the digital outputs on a PIC 16f627a to drive an H-bridge chip that runs the mini-sumo robots we build in our engineering class.

In FRC robots, however, the main uses for these pins are as digital inputs, particularly as interupts, limit switches, etc. When you examine the data sheet of the PIC chip that drives the RC in more detail you will appreciate just how many different things the different pins on the PICs can be used for, and how elegantly Microchip has structured their design.

While I agree with you that under FIRST rules there are restrictions on the use of digital outputs (and with all the PWMs and Relay outputs available, it's usually not a big deal) but in other applications the digital outputs are quite useful.

Jason