Re: Walking Encoder Values
 

Can you use a multi-turn POT instead?

Re: Walking Encoder Values
 

The optical encoder comes with a centering tool and a disc spacing tool. If you follow the instructions correctly in using those tools, you should not have any problem. We have a student that did not use those tools when assembling the encoder. He pressed the optical disc all the way down and ended up scratching it. So our autonomous acted strangely. After scratching our heads for a while, I finally pulled out the encoder and examined the disc and found the problem. Once we replaced the disc, everything worked fine.

Re: Walking Encoder Values
 

Are you kidnapping my students and making them install sensors on your robot?

Re: Walking Encoder Values
 

Is it why we keep losing our games? :)

Re: Walking Encoder Values
 

My suspects would be, in order:

1. Mechanical slippage between the encoder and the shaft whose rotation it is measuring (you seem fairly sure that this isn't the issue, and I believe you, but in general it is the first/easiest thing to check)

2. Improper spacing between the optical disc and the encoder circuitry. Use a spacer tool when installing the disc.

3. A "smudge" (fingerprint or scratch) on the disc that causes one of the photoreflectors to miss a count or two per revolution. Easiest solution: try another encoder disc.

4. EMI/wiring problem.

5. Code issue. Your code doesn't ever reset the encoder, does it?

6. An absurd pulse frequency (too high of a CPR on the encoder given the speed of the shaft it is measuring). However, in the cRIO era, you need to be well into the tens-of-thousands of pulses per second before this would be an issue, so it is unlikely.

Re: Walking Encoder Values
 

This might not be what's causing your problems, but on our robot, the encoder would be missing ticks off and on; it would read for one second, then it would pause, then it would read some more, and so on. The encoder was plugged in all the way, but we found that the problem was because the wire was going into the encoder at an angle. (that the wire coming off at an angle was pulling the encoder out of a proper connection) We taped the wire so that it comes out straight and haven't had any problems since.

Re: Walking Encoder Values
 

All wires should have a strain relief! :ahh: