PRU firmware loads but produces no output: which remoteproc and pin settings matter?

Confirm the intended remote processor, its running state and the firmware selected by the installed image. Device numbering and supported loading workflows can vary. Check kernel messages for resource or startup errors rather than relying only on the success of a copy command.

Verify that the chosen physical pin is routed to the intended PRU function and is not owned by another peripheral. Compare the board revision, pin mux configuration and firmware register use. A running core can toggle an internal signal that is not connected to the connector being probed.

Use a minimal documented output example adapted to the actual image, then add application code incrementally. Observe both an internal progress marker and the external waveform. Keep power and logic-level compatibility in view when attaching a peripheral or measurement instrument.