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Alaskanphoenix
- 6th January 2006, 14:17
Hi!
I am using a 16f84a with 20mhz to control 10 pots and send the corresponding midi cc message, but the pot command seems to be too slow and if i move the pot very fast it skips many messages! The 10kb pots are connected with a 0.1uf cap. I don't want to change the 16f84a because i have a bunch of them,so how could i fix the problem?

thanks in advance

Ioannis
- 6th January 2006, 19:21
Worst case scenario:

pot at 10K with 100nF gives 1msec time constant.

10 pots x 1msec gives 10msec plus your commands in the programm.

So you cannot get rapid reply with this method. A PIC with ADC I 'm afraid is what you need here.

Ioannis

Alaskanphoenix
- 6th January 2006, 20:34
Thanks a a lot Ioannis.

If i substitute the cap with a smaller one?

Ioannis
- 7th January 2006, 12:11
Yes you can I suppose use smaller caps but I have not checked it. I guess from the idea of implementing that kind of adc the range is limited. I would not try smaller than half the 100nf. I feel that you may have to use a fast analog to digital converter or at least try a PIC with an adc.

Ioannis

Alaskanphoenix
- 8th January 2006, 12:37
I think i'll try some other pic like 16f88 or better the 16f876!

thanks a lot