esp32: PWM duty will be changed when changing the frequency if more than one channel is used. #8345
Description
After upgrading mpy from 1.17 to 1.18, my buzzer can't play low frequency sounds any more.
With further test, it shows that 5EF0 the pwm has no output when frequencies < 611Hz.
from machine import PWM, Pin
pwm = PWM(Pin(5)) # also tested with Pin(2)
pwm.duty(512)
pwm.freq(611) # it works, digital multimeters shows freq 1222Hz
pwm.freq(610) # no pwm output, digital multimeters says freq is 0And after switching back to mpy 1.17, pwm.freq(610) works fine. I'v tested with another board and I still got the same result. I'm sure this is an issue introduced by v1.18.