This project is a Microchip PIC microcontroller with an RS232 serial interface on one side and an Infra-Red receive and transmit interface on the other.
By sending commands on the RS232 interface it is possible to receive or transmit a sequence of bits modulated as a series of on/off states in a 38 kHz infra-red carrier signal. Infra-Red remote controls use a carrier signal (typically around 38 kHz) so that there is no confusion with sunlight etc. The carrier is turned on and off to represent the bit sequences at a lower rate, for example 500 Hz).
RS232 to Infra-Red Interface - [Link]
This cool device can be used in many areas. You can connect up to 8 different devices to 8 relays and control them remotely with IR transmitter.
The whole system consist of two parts: IR transmitter and receiver with controlled relays. Transmitter sends RC5 format IR signals modulated to 38kHz carrier. Code is generated by PIC16F630 microcontroller depending on which key is pressed. Receiver also has same PIC16F630 on board which decodes received signal and activates related relay. If you like this project you can build it by yourself as all necessary files are available for download.
Control up to 8 devices with IR remote – [Link]