Here in China, there is no central air, so my office is heated/cooled by a room air conditioner. Because of this, it's cold when I arrive at work in the winter, and hot in the summer. So an idea was born to create a small, battery powered, IR emitter that would issue the same "ON" command the AC's remote control does, but does it an hour or so before I get to work in the morning. The end result should be a nice warm office in the winter and a cool one in the summer!
Using an ATTiny13V, a single AA rechargeable battery, and a little code, I now arrive to a warm office in the winter and a cool one in the summer.
Project website: http://www.thebloughs.net/hobbies/electronics/midea_ir/