First working version

Author: ladyada

rawirdecode.pde

@@ -0,0 +1,89 @@
+/* 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");
+  }
+}