Encoders not working

[dmlawrence]

I am using the quadrature encoders that were included in the kit. I am experiencing an odd problem where the signal suddenly drops out soon after we start driving. I have attached a graph of the signal (after a low-pass filter) that shows the dropout very clearly. Here are some possible causes that have occurred to me

(1) The signal, which is passed through two solder joints and then a DB-25 connector, is somehow degraded to an unusable point.

(2) The camera processing is interfering with the encoder counting. (CPU usage is in the 80-90% range.)

(3) Something else?

Which of these is most likely? Any help will be most appreciated.

David
Team 1751

[Greg McKaskle]

You don't give any details on how you are using the encoder, but there is a FAQ for LV that explains that the 4x option with averaging set to 1 will return a rate of 0 once the encoder moves very fast. This is not an issue with 2x encoders or when averaging is set to 2 or any other valid number. Also, the distance or count is fine, it is only the rate that has issues.

Greg McKaskle

[dmlawrence]

Thanks for patrolling the forums during such a crucial time for teams! I had been using a separate averaging VI, not the encoder library's built-in averaging functionality (which was indeed set to 1 sample). Changing over to this averaging solved the problem. I'm glad this was such an easy problem to diagnose!

David