How do you test a TV remote?

A few years ago, this question would have been easy to answer. Remote controls were once fairly simple devices. The circuitry inside a television was generally an "add on" to the television. Often, manufacturers used remote control circuits developed and produced by integrated circuit manufacturers so they used standard protocols.

Modern televisions are very different. The remote control is far more complex with a vast array of buttons. Every button generates a string of pulses that is unique and manufacturers normally use a coding system that is not published. To make it harder, the remote control circuitry inside the television is now part of the control micro-processor that resides in almost all televisions. The information needed to build a new remote control can be very difficult to obtain. Most manufacturers will not release the information so a would be constructor will have no help.

On a more positive note, there are various web resources that offer information on remote control codes. The information is often in the form of a file that specifies the string of pulses used by each of the buttons. Although much of the information is accurate, it is no small task to convert the file into something meaningful. It can be equally hard to construct a remote control that uses the information.

Theoretically it is possible to use the coding information and program a small processor to send out the pulse strings. The PIC by Microchip is one of several components that would be suitable. There is a significant amount of programming to be done as well as some electronic design to turn the PIC output into an infra-red signal. Adding a large number of buttons demands some electronics knowledge and experience too.

For most people, the steps to make a remote control are too numerous and complex to be worthwhile. The end result will be no better than the manufacturer's original part and will probably be far more expensive.

If, despite the warning, you decide to go ahead with it, you will need a certain amount of luck and a great deal of persistence. Don't be afraid to ask for help in a forum or two. There are people who work in the field and they can be very helpful indeed.