All microcontroller developers for debugging and device control use serial communication via a computer (or other device). The most commonly used serial communication is RS232. Ten years ago, every computer was equipped with a serial port, but today it is uncommon on PC platforms and almost non-existent in laptops.
The cheapest way to remotely control a device within a visible range is via Infra-Red light. Almost all audio and video equipment can be controlled this way nowadays. Due to this wide spread use the required components are quite cheap, thus making it ideal for us hobbyists to use IR control for our own projects.
This part of my knowledge base will explain the theory of operation of IR remote control, and some of the protocols that are in use in consumer electronics.
There is not much info out there about the RCA protocol so I basically took a remote (an XBOX remote that uses the RCA protocol) and started analyzing the flow. I also had help from looking at the lirc remote archive.It is actually quite similar to the NEC protocol.
This protocol is designed by Philips and transmitters are produced by Philips (SAA3008) and ST (M3004). Personally I have never seen this protocol being used in real applications. All information on this page is derived from the data sheet of the Philips SAA3008 and the ST M3004 (10624.pdf).
There are 2 small differences between the two competitor ICs. The Philips IC has two modes of operation, one which is compatible with the ST chip and one which can handle up to 20 sub-system addresses. The ST chip has the capability of switching the modulation carrier off.