I want to measure the current and voltage from a set of small solar panels (about 10V and 100mA but not settled yet) using a Raspberry Pi. There will be between 4 and 6 panels.
This project will need to run without a lot of maintenance for a reasonable amount of time. It should be part of an interactive museum display on solar energy.
Voltage: Use a voltage divider from positive terminal.
Current: Use a 1 ohm resistor and measure the voltage drop. I want to use a 1 ohm so it does not influence the reading based on head or various other factors.
Since there is not ADC on the PI, I would like to use an MCP3008 partly because I know it supported with the PI, and partly because it is available in an SOIC and DIP version. The final version of this will be a custom PCB. And it has 8 channels so I can hook up 4 panels.
Are there going to be any issues adding a second MCP3008 chip if I need to add more than 4 panels? I have never done GPIO programming on a PI.
Is there a better way to measure the current? I also looked into using a PMIC like the INA212-214-Q1 from Texas Instruments but it seemed a lot more complicated than just using the 1 ohm resistor.
Is there anything I am missing?