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First working version

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0 parents commit ccf89c5c0c3e4c855e12ae0b624afa8e114b9f40 @ladyada ladyada committed Oct 5, 2010
Showing with 89 additions and 0 deletions.
  1. +89 −0 rawirdecode.pde
89 rawirdecode.pde
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+/* 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 & (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");
+ }
+}

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