Melanie,

Although I don't know much I thought hardware PWM was for outputting a PWM signal in the background. I'll have to look more because even the datasheets at Microchip talk about outputting a pwm but nothing about measuring pwm in.

Any specific chip you'd advise me to look at? BTW, this has absolutely nothing to do with Life support. It's measuring Exhaust o2 levels of engines.

Richard