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Chris is me
13-05-2011, 05:36
So we at Shaker Robotics are pretty cheap. We want to wire up a drive base using a Vex controller to drive PWM signals since it's much cheaper than another CRIO + DSC. However, all of our Victors are on our competition robot. Since we have tons of Gray Jaguars lying around, and since we're never going to use them on a competition robot, we want to use those instead of Victors on the Vex-driven drive base. Is there any reason this wouldn't work?

My knowledge of electronics is very limited, but as far as I know, PWM is PWM so I don't see why it wouldn't work.
notmattlythgoe
13-05-2011, 06:27
I believe that we do this on our Relay for Life robot. I can check when I get to the school today.
notmattlythgoe
13-05-2011, 06:56
That is exactly what we did, and it works perfectly fine. We have 2 grey jaguars running through PWM.
Gdeaver
13-05-2011, 07:31
We have done that. However the jags default code uses a wider pulse than what the vex controller outputs so you will not get full speed. They could be calibrated to give full speed.
Chris is me
13-05-2011, 07:47
We have done that. However the jags default code uses a wider pulse than what the vex controller outputs so you will not get full speed. They could be calibrated to give full speed.

Is it "close enough" to full speed or dramatically less? How would we go about calibrating a Jaguar to work well with Vex?
Ether
13-05-2011, 08:01
How would we go about calibrating a Jaguar to work well with Vex?

See the calibration procedure on Page 13 of the MDL-BDC24 datasheet (attached) or Page 13&14 of the GSG (attached).
Taylor
13-05-2011, 08:07
See the calibration procedure on Page 13 of the MDL-BDC24 datasheet.




Something tells me he didn't have to look that up.
Joe Ross
13-05-2011, 09:31
Is it "close enough" to full speed or dramatically less? How would we go about calibrating a Jaguar to work well with Vex?

Based on PWM pulse widths, it should be about 60%, but I've never tested it.
Foster
13-05-2011, 10:30
From actual testing with a Jag and a CIM motor it's about 50%. The recalibration procedure is easy to do. When you are done MARK THE JAG THAT IT'S BEEN CHANGED. Otherwise you will have some unhappy FRC / CRIO programmers and electrical team members.
krudeboy51
13-05-2011, 14:03
it works because we tried it on our 2008 robot, fully operational! its great for a practice robot