Bithead recently embarked on a journey to replace a pair of defunct residential shades with motorized window blinds. After researching and deciding on a specific brand, Bithead got to work building a digital bridge to interface the blinds with his home automation system.
“I wanted to make the device small and wireless. I had an extra Arduino Fio (Atmel ATmega328P) left over from an earlier project, so decided to use that as the base of my solution,” Bithead explained in a detailed blog post.
“Next, I purchased an Xbee S6B to allow the Fio to participate on the house WiFi network. Finally, I purchased some 3V Reed Relays from Meder Electronics.”
On the software side, Bithead wrote a quick app to send command to the Fio, going through at least three major iterations before hitting on a stable version. He also coded an HTML5 interface that allows him to manually override the blinds from any mobile device connected to the house WiFi.
“I used slider controls in the app to set the height of the blinds which makes the app more intuitive,” he continued.
“In addition to a manual control option, I also added some functionality to allow the app to control the blinds autonomously.”
Basic rules include:
- At sunrise, raise the blinds to let in light
- At sunset, lower the blinds to provide privacy
- If the room gets too warm, lower the blinds to 50% to provide some shade
- When the room returns to a target temperature, raise the blinds again to let light in
- When the house is unoccupied, lower the blinds for privacy
“I already have a sunlight sensor configured to trigger the interior stair lights. I also already have a temperature sensor in each room and house occupancy sensors, so writing the rules was a simple matter of tapping into those database tables and grabbing the current state to determine if the blinds should move,” he added.