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TDA4VM: QEP under Linux

Jason Kridner1
Prodigy 166 points
Part Number: TDA4VM

Has anyone validated the eQEP peripheral?

I've enabled the eQEP driver using the code in the mainline Linux kernel: https://lore.kernel.org/all/20211204163409.2a4fd5c5@jic23-huawei/t/#ma6714213d0ca9e5665a28bdc9100949a0b559b1f

I then attempted to monitor the QEP.

root@TDA4VM:/sys/bus/counter/devices/counter0/count0# echo 1 > enable
root@TDA4VM:/sys/bus/counter/devices/counter0/count0# watch -n 0.1 cat count

root@TDA4VM:/sys/bus/counter/devices/counter1/count0# echo 1 > enable
root@TDA4VM:/sys/bus/counter/devices/counter1/count0# watch -n 0.1 cat count

Then, I send pulses using a Pololu quadrature encoder (https://www.pololu.com/product/3499).

I'm not seeing the value change.

Any thoughts on what I might be doing wrong? Has anyone validated this peripheral on TDA4VM?