A0 pin not working when full PV system in use

I am using the DFRobot Leonardo with Xbee R3. I am using the A0 pin to read a 0-5V voltage from my voltage sensor, which samples and steps down 130VDC from a solar panel, in parallel to 0-5V for my Arduino to read.

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PV Array is 7 Panels in Series, Vpeak 18.7V Apeak: 11.23A
Voltage Sensor in Parallel
Voltage Divider to step down to 0-5V range
Full circuit layout

When the PV system is in open circuit mode (not connected to the grid), A0 can read the voltage without any issues and output's it into my serial monitor. When the PV system is connected to the grid, A0 seemly shut's itself off and i no longer get any serial output. Testing with multimeter shows that the A0 pin is still getting a voltage in the range of 0-5V.

My assumption is that when a load is applied to the system, either A0 shuts itself down to protect the board for some reason, or the current is not flowing through the voltage sensing circuit due to it's higher resistance.

Current sensor is a 0-20A ACS712 board.

  • 3
    The analog pin can not “shut down”. It makes no sense. What can happen is that your Arduino shuts down (e.g. for lack of power) or your program locks itself inside an infinite loop (a bug). You may want to blink the onboard LED in your main loop() just to confirm your program is still running. Also, the information you provide in the question is not enough to help you: everything looks correct. You should provide a complete schematic and post a Minimal, Complete, and Verifiable example for the software side. – Edgar Bonet Oct 11 '17 at 7:49
  • Definitely not a lack of power as i am connected to my laptop's USB port for data and power. Program is still running, data is being recorded, shown on serial monitor and sent to a datalogging server (ThingSpeak) gyazo.com/a17799f90fa1f17ad59848350a9c9183 – Marcus Xing Koh Oct 11 '17 at 8:13
  • Does the laptop and the circuit share a common ground? – Code Gorilla Oct 11 '17 at 9:30
  • 1
    You wrote in the question: “i no longer get any serial output” and then in your comment: “data is being [...] shown on serial monitor”. This seems like a contradiction. Please clarify. – Edgar Bonet Oct 11 '17 at 9:31
  • Sorry for the confusion. My serial monitor prints both Voltage and Current readings from my sensors every 0.5secs. When the system is not connected to the grid (i assume no load) the serial monitor shows my voltage value e.g 130V, which is verified by multimeter testing. However, when i do connect the system to the grid, serial monitor will show the voltage value as 0V. When i disconnect the grid again (i assume removing load) serial monitor starts showing the correct voltage value again. – Marcus Xing Koh Oct 11 '17 at 9:35

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