AVR-Chat

--- In AVR-Chat@yahoogroups.com, "Phil" <phil1960us@y...> wrote:

> with a photo transistor, you simply
> pull it low and take the output 
> from the emitter.

I would think you'd need a comparator so that the input to the MCU 
was a proper logic level and not some analog signal that could spend 
a lot of time floating around between the thresholds.  Especially if 
you're expecting it to generate an interrupt.

Graham.