I will try and give as much information as I can, Really need some expert help solving this
I am working on a little project to read the voltage of my leisure battery and print it out over serial. So far I have worked it all out on a breadboard and it was working well.
Since moving to strip board and changing the Arduino's power source from USB to VIN it has started giving me problems. (Using the same PSU)
I have a 12v step down PSU like the one below, to power the Arduino Nano.
I am using 22k and 10k resistors to divide the voltage from the battery and connecting to the Analog pin (0) Voltage from the battery is around 12.30vdc and using common ground of course since everything is powered from the same source.
The only other things being powered from the Arduino itself is a Bluetooth module although I have tried powering this from the PSU separately still with no results.
The problem must be the Arduino being powerered from VIN @ 5vdc When using the power supply's USB to the Arduino the problem disappears and all works as expected.
Anyone have any ideas? I have searched the forum and internet and decided to post the question as a last means.
EDIT: The voltage read out is a few volts to HIGH when using VIN to power the Nano. I get a reading of around 14-15vdc when the battery is in fact 12.30vdc