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Unread 20-03-2011, 14:43
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PhilBot PhilBot is offline
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AKA: Phil Malone
FRC #1629 (GaCo: The Garrett Coalition)
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Tracking down a stuttering JAG/CAM drive.

I continue to try to get my drive working with encoders/Cam etc.

I currently have a problem in that my drives Stutter as I drive.

By this I mean that when they should be driving smoothly they seem to freeze momentarily on a semi regular basis... eg once a second.

To track this down, I dropped back to a raw Robot Project (LabVIEW) and just switched the Open Drive to a CAN version with ID's 11 and 12 (to match my Jags).

Result.... it rans a smooth as a baby's.... you get the idea.

So I slowly started stripping code out of my own app untill the stutter went away (boy I wish I undserstod the safety code)

Bottom line is very interesting. When I took out the Compressor code, my drive went smooth.

I have replicated the problem with the Basic Robot code. If I open a compressor VI in Begin (and save the ref nin a global) and then in Teleop I just do two calls.... one to read the Compressor status, and one to Stop the Compressor (normally used in response to a compressor on/off switch on the DS)

With these two VIs called once per teleop cycle, my motors go back to stuttering once a second.

How is it possible for these two simple calls to cause this problem? I've attached my simplified test code. Only chanages are to Begin and Teleop.
Attached Files
File Type: zip CAN Test.zip (196.5 KB, 10 views)
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Phil Malone
Garrett Engineering And Robotics Society (GEARS) founder.
http://www.GEARSinc.org

FRC1629 Mentor, FTC2818 Coach, FTC4240 Mentor, FLL NeXTGEN Mentor

Last edited by PhilBot : 20-03-2011 at 14:45.
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