DisclaimerPlease, proceed carefully following the tips published in this blog, specially when Main Power is involved. I'm not responsible for any damages caused by what is written in this blog.
Data acquisition - Photovoltaic production
by Marco Lamanna
Another kind of data I would like to acquire is the production of my photovoltaic plant, a 3 kwp plant built over my roof and made by SUNAGE 250 swiss modules and AROS SIRIO inverter.
I also received a little energy monitor tool, which allows me to verify power production through a wireless display. This display is able to store data in a little sqlite database. Through a USB connection, it lets me view and download data using a PC.
This tool is called OWL
My model is the OWL+USB CM160.
The OWL has a little bug because it also detects reactive power when the inverter is switched off (during the night for example...)
For my purpose I have to connect OWL to Raspberry. Unfortunately this is not supported and there aren't official drivers. Making some research over the internet, I found a good linux open source interface for OWL: EAGLE-OWLhttps://github.com/cornetp/eagle-owl
I compiled and installed this software directly into the Raspberry. It is a background process which detects the CM160 e gets the database data.
This is the shell of Raspberry where you can see the eagle-owl software and database files.
This process will run automatically on startup. Then I wrote a little php script which is able to read CM160 database file e put its data into mysql. In this way I could store all historical data which will be displayed through a web interface.
This script will run on Raspberry every minute (standard cron task).