How do I read my ADC input only after the transition from a low to high occurs?

[sougata]

Hi,

I would recommend that you tie the square wave input to the INT pin and set the AD conversion bit as soon as an interrupt occurs. Also set a software flag so that your program knows that a new sample is available. You can call this routine or just poll the software flag to update your results. However you should also introduce some delay before setting the ADON bit to ensure proper acquisition.

Regards

Sougata

[jessey]

Thanks Sougata,

I'll have to look into the manual more and try to absorb some of the information on how to do that. I've never used interrupts before so this will be a learning experience for me. After a quick look ay the manual, I take it I can connect my square wave output from the CMOS circuit to either pin INT0 (pin 33), INT1 (pin 34) or INT2 (pin 35).I guess I'll be using the PORTB Interrupt-on-Change feature.

Anyways it's getting late here so I'll have another look tomorrow evening and see what I can come up with between the manual and the archives. When I get a better understanding of what I'll have to do to use the Interrupt-on-Change feature (which will probably take me a few days but will be time well spent) then I'll come back with some questions.

Thanks Again
jessey