IR Burst Decoding

Forum 2005-2010 (read only) Hardware Interfacing
1

Hey I am trying to make a duplicate of my TV remote from scratch, So far I have managed to build a receiver using a solar panel hooked up to my mic in, and audacity to record the bursts.

My problem is that I am not sure how to decode these bursts so that I can output the same bursts in an arduino program, i've read a bunch of guides and they tell me to measure the length of the bursts On/Off so I have done that, but what do you do with those numbers? and how would you go about programming that?

Any help is appreciated,
Thank you!

2

There is the input from the IR reciever, 90.884ms OFF, 23.401ms ON.

3

but what do you do with those numbers?

You use them to reconstruct the waveform you originally recorded. You see there is not enough memory in the arduino to record everything at the sample rate sufficient to record the 30KHz ish modulation. So you time the length of a burst. Then when you play back you recreate that burst for the required time.
You might want to recreate the modulation by rapid switching of the LED in software or better by feeding the aoutput of the arduino to a 555 timer and letting it switch the IR LED.

4

There are libraries out there that allow you to use digital PWM pins to pulse IR codes over 38kHz.

And if you'd like a how-to to follow, you might like reading;

and

and you can download my sketch at the bottom of this page and alter it to fit your needs

5

PERFECT, thank you so much!!