- does the battery need to be connected directly to the arduino somehow? can the analog 0 only read a voltage signal if that signal is coming from the arduino? if that's the case, how would you send the voltage through the arduino, and if i did that, wouldn't a 9V battery fry the board?
- you mention the internal reference pin, but there is also the aref pin that can be used for external voltages. 1) what is the internal reference pin? and 2) might the aref pin be a better way to measure a voltage than analog 0?
You need to limit the voltage on the input, it must be 5V max !!
Also, I didn't mention this, but the Arduino is currently powered by USB, but eventually, it will be powered by another connection to a solar battery.
If you are powering the board though the Vin pin, you must supply a regulated 5VDC. There is no on-board voltage regulator for higher voltages, which will damage the board.The Yún is also compatible with PoE power supply but in order to use this feature you need to mount a PoE module on the board or buy a preassembled one.The power pins are as follows:VIN. The input voltage to the Arduino board. Unlike other Arduino boards, if you are going to provide power to the board through this pin, you must provide a regulated 5V.
1. Will the Arduino need a very consistent 5V? What if the 12V goes from 12.7V to 12.3 V. Will that adversely impact the Arduino's ability to read?2. Is a voltage divider the right way to do this? I also heard mention of a PoE module, but am not sure what that is. It sounds like regulated 5V would be enough to power the board, but I want to make sure I'm not missing something here.