More than 6 RC digital input interrupts?

[Jared Russell]

I'm trying to get all of our systems up and running, and it would make my life a lot easier if there were a way to get 8 interrupt lines running. Every bit of FRC code I've seen has a maximum of 6 (on rc_dig_in01 to rc_dig_in06).

Is there a way to get more without having to multiplex the interrupt lines externally?

[Andrew Morris]

There are only 6 external digital interrupts on the RC. One way to add more is to have a second controller(I have used a VEX controller) with encoders or other devices using interrupts plugged in sending signals back to the RC through an analog output(PWM). However, this design requires the use of an interrupt port on the RC and some fancy code work. I used 1 PWM on the VEX controller linked to 1 interrupt on the RC to send a number 0-255 to the RC with reasonable accuracy then had the RC recognize the number as a command(100 means drive forward for example). This also allowed me to do calculations on the VEX controller and ease the load on the RC.

[Alan Anderson]

Digital input pins 3-6 are already "multiplexed" into a single interrupt. You will indeed have to combine signals externally to make them all cause one of the hardware interrupts to occur, but extending the part of the software that checks to see which pin actually caused the interrupt is straightforward.