Analog input to a PIC with built ADC
Analog input to a PIC with built ADC
(OP)
WHen hooking up a 0-5VDC analog control input to a PIC uC is it advisable to connect the signal input to a buffer stage and the a 10Hz low pass filter, then connect to A0 of the PIC?





RE: Analog input to a PIC with built ADC
Any filtering really depends on what the signal is used for and the environment the circuit must live in. Without more details, it is difficult to properly answer this question.
RE: Analog input to a PIC with built ADC
RE: Analog input to a PIC with built ADC
TTFN
RE: Analog input to a PIC with built ADC
Meant:
Remember that if you use a resistor larger than about 2.4K you MUST use a cap.
RE: Analog input to a PIC with built ADC
The other thing: the 0-5V is probably not the real effective range of the ADC, so you'll need to scale it to below 5V.
An analog front end filter also helps a lot by rejecting frequencies that you'd need to sort out digitally.
If your goal is make the cheapest PIC controller, I'd say don't put anything except may be a resistor but remember that you might get a call later from some unhappy people.
RE: Analog input to a PIC with built ADC
Try this link and watch the seminar on "Do I Filter Before, After, or Never?"
I usually get away with just an rc.
Maybe a diode clamp to vcc because the analog pins seem
to be more susseptable to over voltage.
RE: Analog input to a PIC with built ADC