How accurate is the ADC on PIC18?
How much accuracy can I expect with a PIC18F2550? I'm using the example code from microchip for some simple ADC and compared with my multimeter (it's a good multimeter, not a cheap supermarket special) it's reading about 0.2V higher than the actual reading (the error is less at lower voltages). Is this normal?
Last edited by chris414; 15th December 2009 at 06:35 PM.
How good is your reference voltage? Did you choose Vdd as the reference for the ADC or are you using a precise external reference?Originally Posted by chris414
What is the source feeding the ADC?
Assuming you used a voltage divider, the divider resistors' accuracy makes an enormous difference. As much as +5% on one and -5% on the other (worst case) is a lot of error!
The PIC18F's ADC is just as accurate as the spec sheet (and errata sheet) says.
Last edited by Oznog; 15th December 2009 at 11:26 PM.
I thought what I'd do was I'd pretend I was one of those deaf-mutes.
if you had it set up right you should be within 0.01volts of actual
Reply With Quote
