[pilleya]

Originally Posted by FRCTeam2906

With this year's game in mind, my team is looking at using small single LEDs to light up various components on our robot. We have had trouble running multiple functions on our Arduino at once (randomized led fading and led strip program). Since this has not been working we are looking into other methods or powering this LEDs.
With regard to rules in the past, would it be possible to wire individual LEDs to each motor controller output, with a motor attached as well? This way we should see a dimming effect when powering that motor. We are not sure if this rule (R53), or others prohibits this.
"R53 Each power regulating device may control electrical loads per Table 4-4. Unless otherwise noted, each power regulating device shall control one and only one electrical load. (2016 FRC Game Manual, firstinspires.org).

Would it make more sense to use a relay? Also, where would we find/buy a relay and what type should we purchase, if necessary?
2nd part of R53:
*Multiple low-load, pneumatic solenoid valves, electric solenoids or CUSTOM CIRCUITS may be connected to a single relay module. This would allow one (1) relay module to drive multiple pneumatic actions or multiple CUSTOM CIRCUITS. No other electrical load can be connected to a
relay module used in this manner."
(2016 FRC Game Manual, firstinspires.org).

First up it is illegal to run something such as LED's in parallel from the Motor Controller Output. Even if it wasn't they wouldn't light up at all when Motor isn't being drive and would be very dim most of the time depending on the Duty Cycle of the output. Also the LED's would actually be the brightest when the motor is at fully power( 100% duty cycle) rather than the dimmest. They would also probably not appreciate the Pulse Width Modulation and die.

If you are using single LED's rather than strips the LED's are probably quite high in power( and thus draw a lot of current) so you will most likely need to use a Spike Relay.

You can use the Solenoid Outputs on the PCM as these are basically inbuilt little "relays"(solid state) which then control the main solenoid which shuts/opens the air flow. But you need to be careful and each port on the PCM can't supply a lot of current and you risk blowing the fuse on the PCM which will mean no pneumatics.