Hello List, I am trying to measure voltage levels of two IR photodiodes. The voltage varies from about 0,2 to 0,5 volts.
My device is 16F873A. I have following ADC setup: ----------- code start ------------------- const bit ADC_HIGH_RESOLUTION = low const byte ADC_NCHANNEL = 3 -- 2 analog channels on AN0, AN1 const byte ADC_NVREF = 1 -- VREF+ is AN3 include adc adc_init() ----------- code end ------------------- The photodiodes are connected to AN0 and AN1, and I have a 4K7 potmeter as voltage divider on AN3. I am showing the values from adc_read_low_res(0) and adc_read_low_res (1) on a LCD. The vref does not seem to be working as I expected, it makes no difference how I set the potmeter, the values I read are always the same (in a range of 12 - 22, so that fits when vref+ is vdd) What am I missing? TIA, Sander --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "jallib" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/jallib?hl=en -~----------~----~----~----~------~----~------~--~---
