Chris’ cousin has a chicken coop and it is a pain to wake up early in the morning to open the coop door and close it at the end of day. Chris took up the challenge to automate the door armed with a 2.1Watt solar panel, relays, a battery and a Launchpad. You can see the block diagram below. The whole system gets its power from a 12V/7Ah accumulator which is charged by the solar panel. The motor is salvaged from a vehicle wiper mechanism and  is driven by a homemade h-bridge using the BTS7741G driver. A photo-conductive cell in a voltage divider network acts a brightness sensor. His page details all schematic very well with pictures for each stage. Code and schematic are available at his page.

Solar-powered automated chicken coop door opening in the morning from Christian Wolpert on Vimeo.