I am using adc pins on new impc001 breakout board and seeing some erratic readings on imp central. I am using short unshielded wires (100mm) to external low impedance sources.
The adc counts can vary by a few thousand counts each reading at 30 secs intervals,
This sounds very high and just wondering do I need some buffering and filtering of adc inputs to improve the readings.
Adding a capacitor to the input (eg 100nF) is certainly worthwhile as the ADCs are muxed and so you get charge injection as the input is selected. Try that?
Ok thanks Hugo.
That certainly made a big improvement by adding those caps on breakout board.
Just wonder do I need to convert the 16bit ADC readings using read command down to 12 bit and how do I do this if needed ?
You can do that just by shifting right 4: new = (old >> 4)
We report as 16 bits as this allows newer devices with more accurate ADCs to be used seamlessly.