I'm trying to determine a way of reading a PWM signal, for example an RC reciever. Clearly there's no "readpwm" function, but i'm trying to determine the best approach.

I see there are the external interrupts on the atmega128, and i know i can generate interrupts from them, but is what they are intended for? potentially? Are then fast enough to detect PWM so that I can get accurate readings?

Am I going about this all wrong and there is a better way with the atmega to do this, or should I attempt to convert the signal to analog with a circuit and just read it via analog ADC.

Thanks,
Ross