BBAI Cloud9 BlinkExternalLED pru example LED does not blink

Hi all,
I am trying to run the PRU example under /var/lib/cloud9/BeagleBone/AI/pru/blinkExternalLED.pru1_1.c and it is not working.
It compiles with the Makefile and after placing the firmware under pru1_1 core (cp blinkExternalLED.pru1_1.out /lib/firmware/am57xx-pru1_1-fw), the pru start correctly (according to dmesg -Hw) with (echo ‘start’ > /sys/class/remoteproc/remoteproc5/state).
However, I do not see any LED blink on P9_25 of my beaglebone AI.
I have checked:

  • the GPIO6_17 DATAOUT register is changing every 0.5s according to devmem2 (sudo devmem2 0x4805D13C) but the LED is still not blinking.

  • pinmuxing is such that /opt/scripts/device/bone/ gives “P9.25 165 D18 e fast down gpio6_17” so it’s seem to be configured correctly.
    Can anyone help me?