Data acquisition - Photovoltaic production

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

http://www.theowl.com/energy-monitors/standalone-monitors/owl-usb/

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-OWL https://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).

My first project - data acquisition system

I started design my first data-acquisition system with Raspberry PI and Arduino. The idea is to have a sensors network which send data to a receiver which, through ethernet, send these data to WEB/APP server.

The main components are:

- one or more sensors
- a receiver
- a DB Server for storage purpouse
- a WEB/APP server to acquire data and let remote user monitoring the system

Here is the design:



More details:

SENSORS

They can send data in different ways:

- wireless RF-433 towards receiver
- ethernet towards receiver
- USB directly towards server

They can be Arduino board or Raspberry PI or others...
Depending on the type of communication, there can be other interface boards or control led...

RECEIVER

It receives data via wireless RF-433 or via Ethernet
Through ethernet, it transmits data to WEB/APP server, for storage and monitoring purpose

It's built over an Arduino boards with Ethernet Shield and wireless RF-433 receiver. There are also control led.

WEB/APP SERVER

It receives data from receiver through ethernet or from sensor directly connected on its USB port
It stores data on DB server
It runs a web application for remote monitoring

The WEP/APP server software is the world famous Apache HTTPD, installed on Raspberry, running Fedora linux distro.

The monitoring web application is written in PHP / HTML5 using Bootstrap framework, which make it responsive.

DB SERVER

It stores data received from WEB/APP server.

The RDBMS is Mysql Community Edition installed on the same Raspberry of WEB/APP server