I have a micro controller (uC) with 1.8V supply and no integrated ADC. This uC must monitor one signal, and check if it is currently 5V or below 4.2V.
I then need to be able to trigger interrupts based on the value, by sensing HIGH and LOW:
LOW for <4.2V HIGH for 5V
Is using the a voltage divider + uC evaluation hysteresis too risky?