Solar Panel Logger

Detects the voltage of a solar panel (read through an arduino) and passes that data to a server via socketio events. Also records the same data locally.

Usage

To run, first install the required python packages:

pip install pyserial
pip install socketio

Then, connect the Arduino to a computer (may be a Raspberry PI). You will need to find the port number that the Arduino is connected to (see this article using the Arduino IDE or this article to find the correct port). It must be changed in solar_panel_reader.py accordingly. You may need to upload the solar_panel_logger.ino file to the Arduino (which is easiest through the Arduino IDE). Start running the Arduino solar_panel_logger.ino file.

On your computer, run the solar_panel_reader.py file and it should start reading the output from the Arduino. You may need to change some of the socketio configuration values or the arduino_port discussed above.

Once the above preparations are complete, the general order of running the solar panel logger are as follows:

1. Sort out the hardware. Connect the arduino, voltage reader, solar panel, and any other necessary components.
2. Run solar_panel_logger.ino (on the Arduino, using the Arduino IDE).
3. Start the socketio server.
4. Run solar_panel_reader.py on your computer.

Connecting the Solar Panel to the Arduino

The solar panel must first connect to the voltage sensor using the provided orange and white wires. The order in which the wires connect matters, so just try both ways until you receive a value in the program.

The negative output of the voltage sensor goes in the GND port of the arduino, and the S output of the voltage sensor goes in the A1 port of the arduino.

Solar Panel Setup Diagram

Output

The local log is stored in voltage_log.csv and has the form:

Timestamp	Voltage Value

Socketio Events

The python script will emit the following events:

Event Name	Contained Data
"test"	{"foo":"bar"}, run once at the beginning of the script
"voltage"	{"voltage":voltage_value_as_an_integer, "timestamp":"Year-Month-Day Hour-Minute-Seconds"}

The python script will properly receive the following events:

Event Name	Action
connect	prints "Connected"
connect_error, disconnect, error, shutdown, stop	stops execution of the script
pause_local_data	pauses the recording of local data
start_local_data	re-starts the recording of local data
pause_socketio_data	pauses socketio client from emitting voltage data
start_socketio_data	starts emitting voltage data from socketio client

Other Resources

• Similar project: https://projecthub.arduino.cc/Aboubakr_Elhammoumi/9c72efc8-7307-4b24-b3b0-05247d976518
• Some documentation for the analogRead() function for Arduino: https://www.arduino.cc/reference/en/language/functions/analog-io/analogread/
• If you wish to read voltage from a more powerful solar panel, you may need to cut the voltage using resistors. These resistors should be placed in the circuit before the voltage reader as needed. This article contains diagrams and an equation to find the necessary ratio between the two resistors: http://www.learningaboutelectronics.com/Articles/How-to-reduce-voltage-with-resistors.php