AVR-Chat

On 7 May 2004 at 0:32, Graham Davies wrote:

> --- 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.
> 

	So use the AVR internal analog comparator. It can even 
generate a direct interrupt or a timer capture interrupt.

	Mark Jordan