First Programming - Victor/PWM help

[popnbrown]

Originally Posted by Ether

What checks have you done to determine that you are actually delivering a signal to the Victor end of your PWM cable?

We've gone through code to ensure we've got the correct PWM Channels being assigned, however we can't probe any of the WPI Libraries deeper (it just won't let us).

As far as hardware, ensure that the Victor and Digital Sidecar are getting power. It's difficult to use a multimeter and see what the readings of the actual PWM cables are but we've tried and it seems as though it's not putting out any power (signal) through the cables.


Other debugging steps have included trying different PWM Channels and PWM Cables, we have yet to try different Victors, but it doesn't seem like a Victor issue.

-Sravan

[Ether]

Originally Posted by popnbrown

...

Do you have access to an oscilloscope?

[popnbrown]

Unfortunately, no.

I just checked with the multimeter again and just poked around (literally) in different ports on the Digital Sidecar. There's 6V from the V+ to the black on the PWM out ports. 0V between Sig and (-). 0v between Pwr and (-). On the Digital IO, however, 5V between Pwr and (-).

Any suggestions Ether in troubleshooting without an oscilloscope?

[Ether]

Originally Posted by popnbrown

Any suggestions Ether in troubleshooting without an oscilloscope?

Do you have a known good Talon or Jaguar?

Give it some 12V power and plug your PWM cable into it. See what the LED does.

[Ether]

Originally Posted by popnbrown

0V between Sig and (-).

When you are issuing a "full throttle" (forward) PWM command, you should have a duty cycle of approx 20% (2ms pulse divided by 10ms period). So your multimeter should read roughly 1 volt across the white (SIG) and black (return) PWM wires. Use the DC setting and observe proper polarity.

[popnbrown]

Originally Posted by Ether

When you are issuing a "full throttle" (forward) PWM command, you should have a duty cycle of approx 20% (2ms pulse divided by 10ms period). So your multimeter should read roughly 1 volt across the white (SIG) and black (return) PWM wires. Use the DC setting and observe proper polarity.

Yup...I removed all the PWMs and checked them, it's giving a 0.75 volt reading in neutral. So it's working correctly.