Update: check out the RFToy — an easy-to-use standalone gadget to control remote power sockets. Also, support for remote power sockets have been added to OpenSprinkler firmware 2.1.1.
For a while I’ve been looking for a way to switch household power line (110V) devices. One of the simplest options is to use a relay that is connected to the power line. This is easy in concept but quite dangerous to work with. You don’t want to accidentally touch the power line wire and shock yourself. A much better option is to use thepowerswitch tail, which insulates the relay and the relevant circuity inside a plastic enclosure, leaving only two MCU pins to interface with. Much safer. But you still have to run wires between your MCU and the power socket. I am more interested in an wireless option.
Recently I purchase a set of remote controlled switch sockets from Amazon. It comes with one remote and three sockets, each of which can be individually switched. The whole package is quite cheap. The way this works is that you plug the sockets into the wall, and when you press a button on the remote, the corresponding socket will switch, thus turning on or off the device connected to the socket.
I took apart the remote control and found that the circuit is quite simple. It’s based on an HT2262 remote control encoder and a 434 MHz transmitter circuit. In fact, the schematic of the circuit is well documented in the datasheet of the encoder:
Read more: Use Arduino to Interface with a Remote Controlled Power Switch