hello im trying to make 2 pwm signals on 25kHz however no matter what i do only 1 channel ever actually works and second channel has no output
its always 13/19 (pwm1) that works and 12/18 (pwm0) never works
at this point after maybe 20 hours of trial and error i think i tried everything so to list few of my failed attemtps
- dtoverlay=pwm-2chan
- different combinations of values in dtoverlay=pwm-2chan,pin=12,func=4,pin2=13,func=2
- 18/19 and 12/13 switching around
- dtoverlay=vc4-kms-v3d,noaudio
- dtparam=audio=off
- different ways of interacting - python, c++, directly editing files in /sys/class/pwm/pwmchip0
so far i didnt notice any errors in programming for example in c++ output of gpioHardwarePWM is 0 which is ok
it doesnt matter what i try it just has no output no duty cycle no frequency nothing
i got 2 raspberries and they have exactly same issue both are pretty much new so i dont think this is actual defect of hardware
im checking it with multimeter
its always 13/19 (pwm1) that works and 12/18 (pwm0) never works
at this point after maybe 20 hours of trial and error i think i tried everything so to list few of my failed attemtps
- dtoverlay=pwm-2chan
- different combinations of values in dtoverlay=pwm-2chan,pin=12,func=4,pin2=13,func=2
- 18/19 and 12/13 switching around
- dtoverlay=vc4-kms-v3d,noaudio
- dtparam=audio=off
- different ways of interacting - python, c++, directly editing files in /sys/class/pwm/pwmchip0
so far i didnt notice any errors in programming for example in c++ output of gpioHardwarePWM is 0 which is ok
it doesnt matter what i try it just has no output no duty cycle no frequency nothing
i got 2 raspberries and they have exactly same issue both are pretty much new so i dont think this is actual defect of hardware
im checking it with multimeter
Statistics: Posted by rymer — Mon Nov 10, 2025 2:18 am