World’s cheapest remote control replicator: just 1$ !
Pubblicato da jumpjack su 20 Maggio 2008
You won’t need anymore complex circuits & complex software to sample commands from your remote control and to replicate them; all you need is just two standard IR led, which you can afford for about 0.50 $ each, or maybe you can extract from a couple of old remotes.
This method was tested with a VIA AC’97 audio card; please report if you have any success with different cards.
What you need:
- 1 spare headphone cable (0$ if you already have it, 10$ if you need a new one)
- 2 IR led (0$ if you have a couple of old remote controls, 1$ if you need to buy them)
- audio recorder software, e.g. Audacity, opensource and multiplatform (Windows/Linux)
What to do:
3) Edit the resulting waveforms
5) “Replay” the waveforms:
a – Plug the emitter into HEADPHONE output of your audio card
b – Position the two leds just in front of your device
c – Press PLAY in Audacity: your device should react to the command you previously sampled.
NOTES:
1 – For unknown reason, playing the resulting signal in Audacity works fine to control my device; but if I save the signal into a WAV file and reload it in Audacity, playing it results in… nothing! Any explanation for this?!? FIXED: it was due to wrong carrier frequency of rebuilt signal, which must be HALF of the needed carrier frequency! (19 KHz for 38 KHz, 18 KHz for 36 KHz…)
2 – You can’t save the signal in OGG or MP3 format, because this format distort the original signal
Please report results of your experiments! Good or bad, please just report and share! 
References and credits at bottom of this page:
http://www.planetmobile.it/jumpjack/LedRem/
Available patents (not mine):
Infrared generator from audio signal source
IR receiver using IR transmitting diode
What can you do with an old cellphone? « Jumping Jack Flash weblog detto
[...] 4) Add an IR led to your recipe, and you obtain an SMS-controlled remote-control. [...]
Turn your phone into an universal remote control « Jumping Jack Flash weblog detto
[...] look at this post to know how to: – build an IR receiver for the PC – sample a remote control – (create a WAV file [...]
Menu Inicio detto
I’ve tried this and it worked great.
I have one question:
Can I save this as a WAV file or something so I can use an iPod for example to reproduce de signal?
PS:Sorry for my english
jumpjack detto
Sure you can use the WAV files on your IPOD: my idea actually started from a similar project… to turn IPOD into remote!
But please tell me if yout Ipod accepts these files, or if they must be in a different format.
(number of channels, sample rate, bits per sample, bytes per sample).
s5vi detto
I tried it and finally works correctly.
Some remarks:
1. I must invert recorded signal.
2. Transmitter cannot work without a simple amplifier.
These issues due to my soundcard (Via on my mobo)
Recording with Ir led is US patented:
http://www.patentstorm.us/patents/6701091/description.html
jumpjack detto
S5vi, thanks for your feedback.
Point 1) is a known issue, that’s way I updated my RAW2LIRC program in such a way it can “flip” the signal if required. Anyway, you can invert the sampling led to avoid this.
Point 2) is quite strange; I have a VIA AC’97 …
About patents: I knew using IR to play sounds was patented, not that recording IR through audio was too; anyway, anybody can use any patented technology as long as he does not sell it. That’s why patents are freely available online:
http://www.freepatentsonline.com/6931231.html
I should have added to credits, indeed…
I will, together with your link.
Ben Hoskins detto
Hi, I’ve a really dumb question, but I’m more software than hardware…
I’ve looked on ebay for “IR LED” to gve this a blast, and I’ve got various specs like below:
Size: 5mm
Forward Voltage (V) : 1.5~1.6
Forward Current (mA): 60mA Continuous, 120mA peak for 10% Pulse Width
wavelength (nm):850
View Angle: 15-30 degree.
Does any of this, like the wavelength, or forward current, matter?
Will this mean that the range of the built remote will be affected?
fyi, my ‘big idea’ is to write a universal remote program to run on my kohjinsha UMPC, where you can associate buttons with sound files, and opensource it so I can:
1) Replace the 5 remotes I have
2) Add support into the mediacentre i’ve written
Cheers!
jumpjack detto
I have no I idea, I bought my leds in a store, just asking for “IR LEDs”.
Don’t you have an old remote no more working/used to get the LED from?
Ben Hoskins detto
Hey,
(I hopefully won’t lose my PC any time soon!)
Nope no spare remotes…
If anything, I keep on losing remotes, which is why a computer based remote is a good idea
I’ll give it a try with the ebay bought LED’s (if anything I’ll only lose £1)
Cheers!
p.s. the instructions have been very useful: i read the ‘How-To Turn your iPod in to a Universal Infrared Remote Control’ on engadget, then was looking to buy the Griffin IR device, which looks like isn’t manufactured any more.
This article has made it possible!
Some New Projects in the Pipeline « Its The Rules detto
[...] read a really cool (read geeky) article here where this dude made a universal remote control for $1 from a set of headphones and 3 IR [...]
iwan detto
i’ve try this, and its working fine.
i tried few more condition, with one or two LED and not used the ground cable, its still can working fine.
the question is how to export WAV audio file for playing in my PSP.
the AUDIO format only working in sample bit rate 96000Hz, thats can’t be save as MP3.
WAV with 96000hz bitrate can played on windows media player, but can’t recognize on my PSP
sory my english not good
jumpjack detto
MP£ wouldn’t work anyway, as it is a lossy compressione method which cuts just the needed frequency!
you should figure out if any WAV player is available for PSP, as WAV is the only uncompressed audio format, as far as I know; any compressd format wouldn’t do the trick.
THese FAQ appear to suggest that PSP does suport WAV format:
http://psp-download-center.com/faq.php
You could try this player:
http://forums.qj.net/psp-development-forum/103679-release-wav-player-psp.html
I think also lower frequency than 96000 Hz should work (try more typical 44100 Hz for example).
Please let me know if you do succeed in using PSP as a remote!
And, in case it works, some pictures would be cool!