remore control ?

anybody got an idea about how to sample remote control codes using ir rx led and without ripping it appart ? also i do not have access to an osciloscope

i tried parallel port but i think the inputs are too slow...
ultimatly if there's nothing else i'll deal with it another way, looking for an easy way for now

There have been many projects about reading IR codes. The IR transmitted is modulated at about 40KHz. That is to say when the IR emitter is active it is emitting 40KHz pulses. The easiest way to read the output would be to use a matching IR reciever that converts the IR stream into 1's and 0's. If you read the data from the TX pin as you suggested you will have to demodulate the 40KHz signal, easier to use a reciever to do it.

The encoding used differs from one maker to another, I think there about 3 common standards.

This is a serial port version that should work for you
How to build a simple but cool IR (Infra Red) receiver.

EDIT: IR Receiver on a half shell.

tom3000 said:

anybody got an idea about how to sample remote control codes using ir rx led and without ripping it appart ? also i do not have access to an osciloscope

i tried parallel port but i think the inputs are too slow...
ultimatly if there's nothing else i'll deal with it another way, looking for an easy way for now

Click to expand...

Some remote codes are already documented on the net. If not, then using a PIC or other micro to log the pulse coding and send it to a PC would work.

tom3000 said:

anybody got an idea about how to sample remote control codes using ir rx led and without ripping it appart ? also i do not have access to an osciloscope

i tried parallel port but i think the inputs are too slow...
ultimatly if there's nothing else i'll deal with it another way, looking for an easy way for now

Click to expand...

A parallel port is plenty fast enough, I did it years back on a 386SX16MHz laptop running DOS.

As suggested, there are details on the net of most IR schemes, and loads of circuits for reading them.

kchriste said:

Some remote codes are already documented on the net. If not, then using a PIC or other micro to log the pulse coding and send it to a PC would work.

Click to expand...

yeh i thought about doing that also (3rd option) but since nigel says that parallel port should be fast enuff and i too was kinda questioning myself why wouldn't it.....i looked at my stuff again and realized that timing with pc clock isn't gonna cut it (easy way again) pc clock only shows time in milliseconds ...i need to see microseconds duh!

anyway...thanks all

As long as the PC is running DOS, or some other non-multitasking OS, then it should be fairly easy to do. You could use the pc clock to calibrate your timing loops so the code will be somewhat independent of CPU clock speed.

Also bear in mind that access to the ports on a PC is at a much slower speed than the CPU runs - and DOS is far easier to use than Windows, where you have too little control over what it's doing.