RCTIME and POT command are just 'usefull' when your PIC don't have any AD converter. While it's just a pain and real waste of time to do some intelligent calibration, forget them. Choose a PIC with internal AD or use an external one. If you use an external one you'll discover really fast that it just don't worth the investement while a PIC with internal AD are not really much expensive than others without.
Your POT is connect between VCC and GND, the wiper can go directly or through a low value resistor to your PIC AD input.
If your software don't provide any noise cancelation, i suggest to add a ~0.1uF between PIC input and GND to filter the signal a little bit.
If you use the above method, your POT impedance must meet the maximum PIC AD impedance too. Look into your PIC datasheet under the AD section, you'll fiond it there.
BUT if you don't have any POT that meet it, you can even place a buffer between your POT and the PIC. almost any decent op-amp will do the job.
ADCIN is easy to use and work really fine even if you can do it simply by writing/reading directly to the internal registers. That will also provide tighter code.
Last edited by mister_e; - 16th April 2006 at 09:37.
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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