– Smart home application framework
Smart home portal is a web-based smart home application framework which is optimized for smartphone. Refer to the flowing system diagram, the Arm based embedded system (Raspberry Pi with add on boards) should be placed in the home which runs Web server with PHP and CGI/FastCGI supports. The jQuery mobile web front end framework and HTML5 are used to design the UIs which are optimized for both Android and iOS platform.
For the hardware part, the design is based on my previous project – Raspberry Pi Universal Expansion Board, the Raspberry Pi’s 16 pins hardware interface is connected to the Expansion Board which contains GPIOs, RS232, SPI, I2C hardware communication interfaces. I designed a batch of standard Web APIs (based on CGI interface on the web server), those Web APIs will allow the users to talk to the Expansion Board at client side (Smartphone or computer which has internet connection).
The Expansion Board contains an Arm Cortex M3 microcontroller and an Altera MAX II CPLD. The external hardware (Sensors, Relays) can be connected to the standard Pmods on the Expansion Board. The pins of Pmods are remapable by using the CPLD, thus the design is compatible with all existing standard Pmods. The CGI programs on the Web Server can talk to the Arm Cortex M3 microcontroller on the Expansion Board and the Arm Cortex M3 microcontroller can control the external hardware, therefore the external hardware( Sensors, Relays) can be controlled at client side (Smartphone or computer which has internet connection).
I also designed an add-on DC-DC module for this embedded system which can provide 3A current at up to 86% efficiency.