I have now finished working on the mobile app for the Raspberry Pi controlled central heating controller. This is followed from the www.briandorey.com/post/XBee-Central-Heating-Control-via-Raspberry-Pi blog post which detailed how the central heating controller was controlled via an XBee module to the Raspberry Pi.
The phone app connects to the raspberry pi via the apache server and loads data from a MySQL database which is saved from the solar logging system.
The phone app formats this onto the screen to show hot water and solar PV outputs. The app also controls the central heating controller via the raspberry pi and a pair of XBee modules.
The Raspberry pi is using a PHP Serial class to communicate with the XBee module and this sends the commands to the heating controller to turn on and off the hot water and heating circuits.
Initially, I couldn’t get the PHP Serial class http://code.google.com/p/php-serial/ to run and then found a blog post on http://www.fritz-hut.com/ which shows the extra steps needed to add the apache user to have dialout permissions. After a quick reboot, everything worked without any problems.
Overview of communication between the devices:
Mobile Phone App
Xbee - PIC Processor
Central Heating Controller
The code for this project including the Windows 8 phone app and PHP scripts is available to download from https://github.com/briandorey/RaspberryPi-Boiler-Ctrl