A/D interrupt

[HankMcSpank]

Hi,
the AN0 input is 0 unless a key is pressed

If that's the case then why not generate an interrupt when the key (switch?) is pressed & then do an ADC in your interrupt routine.

[starwick]

Thanks for the replay.

HenrikOlsson,
That's what i was think excatelly, but it didn't hurt to ask.

HankMcSpank,
When a key is pressed AN0 go from 0-5v depend on the key pressed(ie; if 0 is pressed 0<AN0<.5V, if 1 is pressed .6<AN0<1.0V......).

Thank you,
Any other ideas or suggestions are appreciated.

[HankMcSpank]

Thanks for the replay.

HenrikOlsson,
That's what i was think excatelly, but it didn't hurt to ask.

HankMcSpank,
When a key is pressed AN0 go from 0-5v depend on the key pressed(ie; if 0 is pressed 0<AN0<.5V, if 1 is pressed .6<AN0<1.0V......).

Oh, now I see.

Then what Henrik said....set a comparator to 'trip' (toggle) at anything higher than 0.4V... use that 'toggling' level to generate a comparator interrupt......do your ADC inside the comparator interrupt routine.

Which PIC are you using? You can likely use the PIC's own internal comparator & DT's CMP_int interrupt....

(http://darreltaylor.com/DT_INTS-14/intro.html )