Pico PIO state machine implements a peripheral: Rotary Decoder substeps example

RE: Pico PIO state machine implements a peripheral: Rotary Decoder substeps example

DAB — Sat, 29 Mar 2025 18:05:14 GMT

Nice project Jan.

RE: Pico PIO state machine implements a peripheral: Rotary Decoder substeps example

Jan Cumps — Sat, 29 Mar 2025 08:55:47 GMT

Stepper motor time. I found an example to control a stepper via PIO. I want to try that out first, then see if I can make it do ramp-up ramp-down.

RE: Pico PIO state machine implements a peripheral: Rotary Decoder substeps example

Jan Cumps — Thu, 27 Mar 2025 20:44:34 GMT

The design has a calibration function.

Suggestion is to create test code that runs the motor stable at 50%, then call that function. It will then return the phase sizes of the encoder.

These values can then be used in the real firmware to have optimal coverage over the whole speed range.

RE: Pico PIO state machine implements a peripheral: Rotary Decoder substeps example

shabaz — Wed, 26 Mar 2025 04:00:44 GMT

Nice.. That's really neat that the rotary encoder handling is all delegated to the PIO. Since there are two, this could also be interesting for motors with encoders, e.g. robotics, dedicate a Pi Pico per pair of motors for instance.

Does the code increment/decrement the count based on the calculated speed too? (e.g. handy if you're using the rotary encoder as a user interface control, incrementing say frequency from 0 to 1 MHz in steps of 1 Hz when moved slowly, but in steps of 100 Hz when rotated a bit quicker, and so on).