We need to measure battery level in addition to using a 4-wire touch screen device. Can one of the four ADC channels be used simultaneously, or does the 4-wire touch system use completely different ADCs?
The ADC and Touch feature are implemented on the same chip on the PXA modules. We use the Audio codec to provide this functionality. You can use our ADCLibrary to read the values from the ADC inputs. Looking at the details, you cannot do this exactly simultaneously with the touch measurements, however, the touch driver and the ADCLib are implemented in a way that you can use it as you want. The library and driver use a MUTEX to ensure the correct behavior. That means there is noting you have to take care about in your layers.
The library is available in our developer center: