Hey thx for your answer. I did not specify the Frequency, I was not even aware of the possibility. I used RepRapFirmware 1.21

Hi,

When I disable the Heater-Pin as such and try to use it as PWM Pin, the duty cycle does not drop from 100% to 0% when I try S255 vs S0. If I invert the logic trough a I in the G-code, the duty cycle goes from 0% to 10% (rough value estimated from the oscilloscope data). I tested this behaviour for several Heater-Pins.
Is there anyone familiar with this problem?

Greeting, Kakadu31.