I am working on a fire detection system with the Seeeduino Xiao board. I have a thermistor attached, and so I’m reading a voltage which provides me with a temperature, after some mathematical juggling.
However, I find that the analogRefernce() function won’t compile: the compiler claims that EXTERNAL, INTERNAL, or DEFAULT are not declared within the scope of the code. Also, I don’t find any reference anywhere to an ARef pin, as exists on many Arduino variants.
So the XIAO appears to have a fixed ARef, internally chosen. Nominally, I would expect that to be 3.3 volts, but since it uses 5 volts as a power supply, that may not be right.
Can anybody enlighten me on this subject?
Thanks in. advance for any insights.