I do a lot of traveling by car, and I usually end up staying in whatever motel is nearest the interstate when I start to feel tired. Often I find that the room has an inexpensive TV that doesn’t have a sleep-timer function. So I created the TV-Go-Sleep, a timer that turns off any TV, after whatever delay time I command. You can build it in an afternoon.
The timer is built around an Arduino microcontroller that’s been loaded with an open source TV-B-Gone library and a few lines of my own code. A simple pushbutton is used to set the delay time, which is shown on a 7-segment display. When the timer expires, the Arduino uses infrared LEDs to transmit all the TV “off” codes it knows, and the TV shuts down. Good night!