How to send FACTORY+3SPEED keys
This page has the goal to show an alternative procedure for sending IR codes to Samsung TV. The procedure has successfully been used for unlocking the Local Area setting available on Service Menu (UE46EH5000) and set the correct one (by sending FACTORY and 3SPEED). In this way I could get a TV 100% compliant to my country (it was bought in another one).
Contents
Theory
The process is based on the fact that the IR key codes are series of square waves at 38kHz of main frequency. The duration in time of the square waves ON and OFF defines the codification of a specific key. By considering a common audio stereo channel (2 mono), it can support max of 22kHz per channel with a total of 44kHz. This means that if an audio stereo channel is created by considering 2 mono channels defined in this way:
- Channel #1= sine wave with 19kHz as main frequency and silent for the time duration at which original IR key square wave is zero
- Channel #2= same as Channel #1 but inverted (basically mirrored)
then, it is possible to emulate the Remote Controller with a simple audio player hardware and a very simple dual led transmitter.
How to build the dual led IR transmitter
What you need is:
- 2 IR Led 940nm 5mm (the typical one present on RC)
- 1 stereo jack 3.5mm
The connections should be as showed below= Led1 (+) must be connected to Led2 (-) and both to one stereo channel, Led1 (-) must be connected to Led2 (+) and both to the other stereo channel leaving the ground not connected
Using the stereo jack+2Led's and having the needed audio .wav files corresponding to the needed RC key code, it is possible to emulate the RC by inserting the jack in a common .wav player and put in play the audio files
Ready to use .wav files
Curently just two codes (required to unlock locked service menu settings) are prepared:
FACTORY 3SPEED
You can download them from SamyGO download area. Direct link here.
Another usefull codes...
POWER ON/OFF CH UP/DOWN
... will be uploaded later.
Important Notes
1. The sound player hardware should have stereo output with enough amplification (I tested on 3 smartphones and it worked only on Nokia N8). It shouldn't be a problem if PC sound card is used
2. The output Volume must be set to maximum level
3. The distance of action (from TV receiver) depends on output amplification (it can be 20cm or 3-4m)
4. The 2 Led must be correctly positioned in order to have enough area where the 38kHz are obtained as sum of the 2x19kHz (see below)
Following some pictures of my IR transmitter based on audio .wav
References
pdca 19:20, 5 July 2012 (UTC)
