I have a Davis Anemometer that I’d like to connect to my arduino uno weather station.
I used the guide stated here: Davis Anemometer Arduino Hookup | Code (Part 1 of 3)
When I tested the wind vane at the bench, the values that came from the pot seemed in line with what the guide stated.
However, on my weather station I have a power bus that feeds all of the components, as well the the MCU.
It can be powered from the USB on the arduino, or the solar panel/battery or whatever.
When I power the Wind Vane from the bus, the pot values are way off, and seem to taper from 0 - 1024.
I imagine that it has something to do with a different resistance in the bus as opposed to right from the arduino 5V pin.
How do I proceed?
Edit: After some testing. Even having the bus ground plugged into the arduino, and running the wind vane directly from the Arduino 5V/Gnd, tends to send the wind vane’s values way out of wack.
Edit: It’s the I2C bus that’s connected to the power bus. Isolating the I2C bus, causes the wind vane to display the correct values.
Edit: Plugging any I2C device into the I2C bus,(which takes it’s 5v/GND from the power bus mentioned above) and then connecting the SCLK and SDA lines, causes the issue.
As soon as I unplug the data and clock lines, the wind vanes values switch back to normal.
Edit: Do I need to maybe connect a lead from the 5V power bus to the AREF?