Using radio frequency (RF) in embedded projects is always cool. You have ability to get rid of wires and transfer information to any direction in some radius. This project uses simple and common transmitter module TLP434A which transmits data by using a 433.92MHz carrier. It’s transmitting range may reach up to 200m with proper antenna and desired power voltage (up to 12V). In this project Transmitter is connected to PIC12F509 microcontroller and powered by 3V coin battery. Such low voltage gives range about 10m.

In other end receiver is also connected to PIC microcontroller which receives commands from transmitter and controls three relays - so three independent electrical devices can be controlled e.g. lights, garage doors. Remote control uses Manchester encoding where data is encoded in a single bit stream where bits are represented as PWM. Project source code can be downloaded here.