No more than four motor controllers run at once

Technical NI LabVIEW
1

Our robot drives on a four motor, six wheel drive train. We plan on using motors as a shooter for the discs, and potentially as part of a pick up mechanism. As the robot is coded now, it opens references to four motors (using the OPEN-Four Motors WPI code, on the Jaguar setting) on PWM 1-4. If we open anything on PWM 5+ the robot simply does not run. The code deploys, and can be enabled, but will not respond to any input on the controller, and does not return any error codes to the driver station. The windows that show the motor speed respond to a joystick input in a predictable manner as well. We ran into the same problem last year, (returning an error code, I can’t remember it off the top of my head but I remember the diagnostics window saying “the code is running too slowly”) but worked around it by using PWM splitter cables to allow one PWM port to send a signal to two Jaguars instead of having the code try to run four motor controllers. Does anyone have any clue as to why the robot won’t run with more than four motors?

In a couple of days we’ll be able to test Talon motor controllers to see if they react differently to this error, but I was wondering if there was any programming fixes for this problem, rather than finding a way to trick the robot.

2

Can you show us your code? That will make it much easier to diagnose the problem.

Have you tried opening five motors, using PWM1-4 and PWM6? (It sounds like you did, but I want to make sure I’ve read you correctly.)

Have you tried opening only four motors and assigning one of them to PWM 5 or higher (with appropriate cabling, of course)?

3

Another potential cause is improper wiring of power to the Digital Sidecar.
Make sure the three power LEDs on the Sidecar are all brightly lit.

4

Remember that the digital sidecar needs to be powered from the 12 volt power distribution board.

5

Thanks for the help, we’ve got it working. We had the sidecar wired to 5V last year, which seems to have been the problem. We just drove the robot with 5 Jags.

6