I need to demodulate signal with frequency 38 kHz coming from remote controller without IR receiver,I need demodulate it and as a result get information from it.
Is there any examples of similiar task.
I woud be grateful for any help.
Hello,
5 years ago I had occasion to do the same thing for a project detailed here.
http://forum.arduino.cc/index.php?topic=8323.0
I used a TSOP1736 salvaged from a defunct satellite box. The data sheet for it can be found here
I simply connected the TSOP output to Arduino input pin, and ran the following sketch, but you could easily write your own -
// *********************************************************************
// Author: Simon Bell.
//
// This may not be the best way to do it, but it's the way I've done it.
// *********************************************************************
int sensorPin = 12; // select the input pin
int sensorValue[850]; // array to store the value coming from the sensor
int datapresent = 0;
void setup() {
Serial.begin(9600); // initialize serial communications at 9600 bps:
pinMode(sensorPin, INPUT);
digitalWrite(sensorPin, HIGH);
}
void loop() {
int x;
while (digitalRead(sensorPin) ==1)
{} // do nothing
for (x=0; x <= 849; x++)
{
sensorValue[x] = !digitalRead(sensorPin);
delayMicroseconds(100);
}
for (x=0; x <= 849; x++)
{
Serial.println (sensorValue[x]);
}
Serial.println ("Done");
delay(10000);
}
This presents a series of 0's or 1's in the serial monitor.
I then pasted the output into an Openoffice spreadsheet to produce the 'graphs' shown in the Simple TV Remote project.
Hope this helps.
AndroidWorld:
I need to demodulate signal with frequency 38 kHz coming from remote controller without IR receiver . I need to demodulate it and as a result get information from it.
Is there any examples of similiar task.
I woud be grateful for any help.
Without?
Then what will you use for "infrared sensing"?
A photo-transistor? And then "look" for 26usec transitions? Or employ other circuitry?
If you're "tricky" and you can open the remote then you could possibly tap the signal that's "driving" its LED - not that I want to go into how you would do that.
Yes (I assume it was a typo and you have the IR receiver that you mentioned)
Follow the examples in the IRrremote or IRLib libraries.
Other links that may be of interest, from our blog:
...and without an IR receiver...