Quote:
Originally Posted by AdamHeard
If you try to read more than 4 encoders at 4x resolution, the remaining encoders will always repeat a zero value. After hours of debugging, seeing the encoders actually generate pulses, but not increment, we were going crazy.
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This is documented in the
WPI Robotics Library User’s Guide. It looks like Java and LabVIEW give errors if more then four 4x encoders are allocated, but not C++.
Quote:
Originally Posted by Tom Bottiglieri
Ugh, don't get me started on encoders and the cRIO. We used a ton of encoders and it seems every combination you can think of using 4x, 2x, and 1x decoding would break something or other. I guess that's what happens when everything on the FPGA is a black box.
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Did you have problems with anything other then the rate output? That was the only reported problem. That's been fixed in off-season updates for
C++ and
LabVIEW.
Quote:
Originally Posted by Gdeaver
The C-rio only has 4 4x encoders. Why not save them for velocity needs?
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I recommend the opposite if you're using the FPGA's rate. With 4x encoding, you get more noise in the velocity due to quadrature phase errors in the encoder wheel. I recommend 1x for velocity and 4x for distance.