Infrared decode sketch for Arduino

Download IRdecoder sketch or copy the below text and paste into Arduino IDE
Also here’s the documentation and pin layout for the¬†tsop4838¬†, which was used for this project.

TSOP4838 PIN 1 – Goes to Arduino PIN 2
TSOP4838 PIN 2 – Goes to Arduino GND
TSOP4838 PIN 3 – Goes to Arduino Vcc (2.5 to 5.5 volts)

 

/* Raw IR decoder sketch!
This sketch/program uses the Arduno and a TSOP 4838 to
decode IR received. This can be used to make a IR receiver
(by looking for a particular code)
or transmitter (by pulsing an IR LED at ~38KHz for the
durations detected
Code is public domain, check out www.ladyada.net and adafruit.com
for more tutorials!
*/

// We need to use the ‘raw’ pin reading methods
// because timing is very important here and the digitalRead()
// procedure is slower!
//uint8_t IRpin = 2;
// Digital pin #2 is the same as Pin D2 see
// http://arduino.cc/en/Hacking/PinMapping168 for the ‘raw’ pin mapping
#define IRpin_PIN PIND
#define IRpin 2
// for MEGA use tese!
//#define IRpin_PIN PINE
//#define IRpin 4

// the maximum pulse we’ll listen for – 65 milliseconds is a long time
#define MAXPULSE 65000

// what our timing resolution should be, larger is better
// as its more ‘precise’ – but too large and you wont get
// accurate timing
#define RESOLUTION 20

// we will store up to 100 pulse pairs (this is -a lot-)
uint16_t pulses[100][2]; // pair is high and low pulse
uint8_t currentpulse = 0; // index for pulses we’re storing

void setup(void) {
Serial.begin(9600);
Serial.println(“Ready to decode IR!”);
}

void loop(void) {
uint16_t highpulse, lowpulse; // temporary storage timing
highpulse = lowpulse = 0; // start out with no pulse length

// while (digitalRead(IRpin)) { // this is too slow!
while (IRpin_PIN & (1 << IRpin)) {
// pin is still HIGH

// count off another few microseconds
highpulse++;
delayMicroseconds(RESOLUTION);

// If the pulse is too long, we ‘timed out’ – either nothing
// was received or the code is finished, so print what
// we’ve grabbed so far, and then reset
if ((highpulse >= MAXPULSE) && (currentpulse != 0)) {
printpulses();
currentpulse=0;
return;
}
}
// we didn’t time out so lets stash the reading
pulses[currentpulse][0] = highpulse;

// same as above
while (! (IRpin_PIN & _BV(IRpin))) {
// pin is still LOW
lowpulse++;
delayMicroseconds(RESOLUTION);
if ((lowpulse >= MAXPULSE) && (currentpulse != 0)) {
printpulses();
currentpulse=0;
return;
}
}
pulses[currentpulse][1] = lowpulse;

// we read one high-low pulse successfully, continue!
currentpulse++;
}

void printpulses(void) {
Serial.println(“\n\r\n\rReceived: \n\rOFF \tON”);
for (uint8_t i = 0; i < currentpulse; i++) {
Serial.print(pulses[i][0] * RESOLUTION, DEC);
Serial.print(” usec, “);
Serial.print(pulses[i][1] * RESOLUTION, DEC);
Serial.println(” usec”);
}

// print it in a ‘array’ format
Serial.println(“int IRsignal[] = {“);
Serial.println(“// ON, OFF (in 10’s of microseconds)”);
for (uint8_t i = 0; i < currentpulse-1; i++) {
Serial.print(“\t”); // tab
Serial.print(pulses[i][1] * RESOLUTION / 10, DEC);
Serial.print(“, “);
Serial.print(pulses[i+1][0] * RESOLUTION / 10, DEC);
Serial.println(“,”);
}
Serial.print(“\t”); // tab
Serial.print(pulses[currentpulse-1][1] * RESOLUTION / 10, DEC);
Serial.print(“, 0};”);
}