Reading PWM Signal with MCU
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Sounds like you are using an analog input on your MCU. If that's the case and you can live with some delay from a transition from 10 % to 90 % duty cycle, the easiest solution is a low pass filter.



simulate this circuit &ndash; Schematic created using CircuitLab
You can also solve this inside your MCU with some code to be able to tell if it's 10 or 90 % duty cycle being sent with no analog filtering.