SAADC resolution conflict

RE: SAADC resolution conflict

trackerfx — Sun, 16 Apr 2023 21:45:07 GMT

Turns out the input to the ADC burned up because I had 3.30v on VCC and was measuring a 3.35v signal. Didn't think 0.05v over would do it but it did. Replaced the MCU and running the signal through a voltage divider first. Everything's working now.

RE: SAADC resolution conflict

JONATHAN LL — Mon, 20 Sep 2021 10:32:08 GMT

Hi,

Maybe you would benefit from looking at the SAADC example here, it looks like you might have misunderstood. If the input range is exceeded then you will just get FFFF on the output.
Run the SAADC example with single ended measuring at VDD, it should give some reasonable results.

Regards,
Jonathan

RE: SAADC resolution conflict

trackerfx — Wed, 15 Sep 2021 21:39:16 GMT

**UPDATE**

Looks like I misread the datasheet (p.232)

'An analog input is selected as a positive converter input if CH[n].PSELP is set, setting CH[n].PSELP also enables the particular channel.'

to mean the ADC would be enabled automatically. This is apparently not the case and I have added a call to the enableADC function in my program just after the setupADC function. The expected flags are now being generated but I'm getting a result of 0 no matter the input voltage.

I'm still wondering if this could be related to my setup configuration as I'm still unsure as to the proper gain/resolution. Can anyone clarify the above quoted texts from the datasheet?