Using CAN and PWM at the same time?

[jojoguy10]

Hi there!

We're wanting to do some bench tests and want to record the motor amperage, voltage, RPMs, velocity, and acceleration. We're going to be using the black jaguars (the only way to measure the amperage and voltage?)

I'm wondering if it's possible to use PWM to drive the motors and CAN to read from the controllers.

I didn't want to drive from the CAN bus just so we can keep from hogging the bus. Maybe I'm mistaken?

The only reason we're using Jags is to read the amperage and the voltage. If there's another way to get these readings without using the Jags, let me know :-)

Thanks!

[cgmv123]

I'm not aware of any reason the Jaguars couldn't be controlled using PWM and monitored using CAN, but I'm also not aware of any reason the drive commands could get caught up in the CAN bus.

R67A disallowed simultaneous CAN and PWM signals in competition this year, but the control system will be revised significantly next year to account for the new control system. I don't expect that rule to change, though.

[adciv]

You can use inline shunts to measure the current on to the motors. Next year, the PDP will be able to provide the current for you.

If you're using CAN to get the current info, why not also use it instead of the PWM?

[Joe Ross]

There's a note in the jaguar source about each of the interfaces being mutually exclusive. I have not tried it, so I don't know if this only applies to inputs, or if the sensor readings are disabled also.