Encoders not working

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.

Team 1751

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

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!