I have a problem with my recently arrived ADS1115 4 channel ADC. I hooked it up to my Raspberry Pi, and I manage to run the example code from the Adafruit Python library, but three of the four channels always show the same value (that is, the value fluctuates a little, as I would expect, but the voltage on the three channels are always equal to each other).
My first thought was that I had made a mistake in soldering, connecting the three pins, but I checked with a multimeter and I couldn't find a problem. Also, the voltage readings only change when one of the three seemingly identical pins are connected, ignoring anything connected to the two others.
Any clues as to what might be wrong?