phatduinoa personal home automation technology arduino


As described in my idea I use the advantages of Arduino Duemilanove board as an easy-programmable microcontroller board in my project. I purchased this board because I was totally new to microcontroller programming when I started building the Phatduino and I found many good Arduino tutorials right away. Although I noticed that Phidgets offers a similar board it was obvious that I would end up with spending a lot of money on sensors and compatible parts with the commercial Phidget kits and was therefore happy to find out that Arduino was an open-source project. I also came across IO-Warrior, but as I wanted to have a computer-independent system this would only have been a poor work-around solution.


4051 multiplexer/demultiplexer chip

The Arduino itself is connected to a self-soldered board that controls a remote control for four light switches that are connected to several lights in my room. The board holds a 4051 chip that is connected to the eight switches on that remote via some opto-couplers.

Furthermore I use Ladyada's ethernet shield and a WIZnet WIZ811MJ module to provide an interface for controlling the system via internet. It was a big deal to get the software for that function done, be sure to check it out at the software page! The Arduino also sends data to my pachube feed, making it available for various applications.


The system gets values from six sensors: Two temperature sensors (one outside and one inside), one light sensor (outside), one moisture sensor located in the soil of my yucca, one sensor used to determine whether my door is locked placed in the doorframe and one FSR pressure sensor in my bed used to check whether I am in my bed.

The user can switch light status via internet by accessing the formular of the interface mentioned before. The Arduino itself can be programmed via a USB connection, serving both as input and output.

Peripheral Equipment

schematic drawing of outside measuring module construction

The outside temperature and light sensor are placed in a square steel that is sealed by a rubber cap on the upper side. On the lower side it features a neat wire netting to protect it from insects etc., which also ensures that air can flow through to measure the correct outside air temperature.

The Arduino is placed in a simple plastic box I got at my local hardware store. It has been customized by placing a nice plexiglass cover in front and hangs on a wall. Please see the attached gallery for photos of the hardware.

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