Potential Issue with the C++ CANJaguar Implementation

Technical C/C++
1

I have our Jaguars all running in CAN communication mode and the ones that are being controlled in voltage control are working great.

However, when I try to control a Jaguar in position control, I am getting garbage back from the encoder. I verified that everything was setup correctly by testing it with the BDC-COM utility. I can see the encoder perfectly there, and I can tune the controller and it works great.

We have a display for the encoder position on the driver station, and if I watch the value here it jumps around erratically (3 -> 8 -> 11 -> 65535 etc.). This makes me think it has something to do with the way the code is unpacking the data from the CAN messages, but I am not familiar enough with the messages to know that this is the case.

I guess my real question is: Has anyone else been able to get meaningful data back from a CANJaguar, and if so, did you have to do anything special? I really need to be able to get the position reliably.

Thanks,
Matt

2

We were able to get it working. We believe that somehow the Jaguar was getting set to expect a potentiometer rather than an encoder. Not sure how though as we only had code in there for the encoder configuration.

Anyway, it works great now.

3

Would it be expecting an Absolute Encoder that outputs a 0-5 V signal based on shaft position? If you are working with a position control mode, that is what I would expect Vs using a relative quadrature encoder.

Mike R.

4