Hi!
I’m trying to read ADC-AUX value using AT+ADC?. After several experiments with input DC voltage i found a great non-linearity in the beginign of the scale. True values appeares after 600-700mV. Does anybody knows what is it: bug or feature?
How much do your measurements differ from what the ADC says?
The input impedance is listed as 1MegaOhm. I assume you have a signal setup such that the input impedance shouldn’t affect measurements.
Well, they differs significantly. For example, when we have 50mV on ADC input Wavecom returns 27mV. With smaller voltages Wavecom measurements rush to zero. Input signal comes from operational amplifire LM358 with 10KOhm output.
It’s a bug that affects also Q24 “old family” and Q24xx “new family” and Q25 “dead engine”.
You may need to recalibrate the ADC (ask to Wavecom support) until the factories will fix the problem.
Since there was an overlap problem the performance still very poor: the reading is locked to ZERO approaching few millivolts.