Introduction: Clone a Remote With Arduino
I recently needed to use the Arduino to control a stereo system, so rather than hack open the remote and wire into it, I decided to simply clone the signal. This was incredibly easy to do. Basically, I read the signal from the remote with a 38khz receiver, and then played it back with an IR LED.
To start, I went to the IR Sensor Tutorial on Adafruit.com and loaded the following script onto my Arduino:/* Raw IR decoder sketch! This sketch/program uses the Arduno and a PNA4602 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 // 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 & _BV(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"); } }