ADC question

[AtomSoft]

hey guys/gals ive been wondering about ADC... i know you can setup the adc on a pic to interrupt when complete but is it possible to setup to interrupt on change?

 

[Nigel Goodwin]

hey guys/gals ive been wondering about ADC... i know you can setup the adc on a pic to interrupt when complete but is it possible to setup to interrupt on change?

No, it's not really anything to do with the ADC - but easy enough to check for a change from the completed interrupt.

 

[AtomSoft]

oh yeah!!! nice one Nigel heh thanks i even forgot about that.

So i can simply have 2 global variables :

1 = oldADC
2 = isNew

On interrupt clear isNew var and check the old ADC value store in oldADC against the new one and if new set the isNew flag and set the oldADC variable to the new data. Correct?

 

[Nigel Goodwin]

oh yeah!!! nice one Nigel heh thanks i even forgot about that.

So i can simply have 2 global variables :

1 = oldADC
2 = isNew

On interrupt clear isNew var and check the old ADC value store in oldADC against the new one and if new set the isNew flag and set the oldADC variable to the new data. Correct?

Yes, as easy as that.

 

[AtomSoft]

Thanks again

 

[birdman0_o]

I read somewhere that you could use an interrupt from a comparator, but I don't see how that would apply if you don't know what it is changing from, but if it changes from V+ or some value you set, it could be done and the ADC would not need to be running all the time .

I like Nigels way though.

 

[Nigel Goodwin]

I like Nigels way though.

I'm embarrassed to have it described as that

It's not even as if it's something I've ever done, but it seems an easy and obvious solution to the problem.

 

[birdman0_o]

Within the context of this thread it is your way.

 

[AtomSoft]

yeah i had a idea of what to do but thought id check if there was another way.