24. 07 2012 15:25
The Raspberry Pi solar data logger project is now live and is the latest version of our previous data logging systems using Arduino and Android + IOIO board projects.
The data is used on a custom reporting website on home.briandorey.com and also on Android and iPad tablet apps.
The Raspberry Pi is used as a data processing and uploading system which pulls data from the following sensors and then uploads to a web server via HTTP GET.
I2C home temperature sensor Microchip MCP9803
1-Wire DS18B20 temperature sensors on Solar hot water collector input pipe, hot water cylinder top and base and also an unused temperature sensor in the box containing the Raspberry Pi board and interface boards.
Mains current Elkor i-Snail-VC Current Transducer 0 to 100 Amps which produces 0-5V DC
Low voltage current sensors using ACS712 30A Current Sensor Modules (sourced from ebay)
The Raspberry Pi ADC board uses a pair of Microchip MCP3428 16-Bit, Multi-Channel Analog-to-Digital Converter with I2C™ Interface chips with low pass filters and voltage dividers on the inputs to bring the 0-5V range down to 0-2.048 which the chips can process. [more]
The completed install showing the Raspberry Pi box to the right with the 1-Wire USB interface and network cable and solar PV system to the left.
The python source code for this project can be downloaded from github.com/briandorey/RaspberryPiSolarLogger
The OWFS One Wire File System is required, download from owfs.org
The Quick2Wire library is used for the I2C communication, download from quick2wire.com
Side view of the interface board showing the DC-DC power supply. There is a small rubber foot which holds the board off the HDMI socket on the Raspberry Pi
Future planned upgrades include saving the data onto a local MySql database and the addition of additional sensors for logging boiler use and also gas usage.