IR Blaster based on http://learn.adafruit.com/ir-sensor/making-an-intervalometer and the results of https://gist.github.com/loisaidasam/5984107 on my A/C controller

IRBlaster.ino

int blasterPin =  12;
int blinkLedPin = 13;

int hangoutTime = 7;
int sleepTime = 5;

void setup()   {                
  // initialize the IR digital pin as an output:
  pinMode(blasterPin, OUTPUT);      
  pinMode(blinkLedPin, OUTPUT);   
  Serial.begin(9600);
}
 
void loop()                     
{
  Serial.println("\nSending IR signal");
  
  digitalWrite(blinkLedPin, HIGH);
  sendIRCode();
  digitalWrite(blinkLedPin, LOW);
 
  Serial.print("Sleeping for ");
  Serial.print(sleepTime);
  Serial.println(" seconds");
  delay(sleepTime*1000);
}
 
// This procedure sends a 38KHz pulse to the blasterPin 
// for a certain # of microseconds. We'll use this whenever we need to send codes
void pulseIR(long microsecs) {  
  // we'll count down from the number of microseconds we are told to wait
 
  cli();  // this turns off any background interrupts
 
  while (microsecs > 0) {
    // 38 kHz is about 13 microseconds high and 13 microseconds low
   digitalWrite(blasterPin, HIGH);  // this takes about 6 microseconds to happen
   delayMicroseconds(hangoutTime);         // hang out for 7 microseconds
   digitalWrite(blasterPin, LOW);   // this also takes about 6 microseconds
   delayMicroseconds(hangoutTime);         // hang out for 7 microseconds
 
   // so 26 microseconds altogether
   microsecs -= 26;
  }
 
  sei();  // this turns them back on
}

void sendIRCode() {
  pulseIR(8880);
  delayMicroseconds(4360);
  pulseIR(600);
  delayMicroseconds(1580);
  pulseIR(620);
  delayMicroseconds(480);
  pulseIR(620);
  delayMicroseconds(480);
  pulseIR(620);
  delayMicroseconds(480);
  pulseIR(620);
  delayMicroseconds(480);
  pulseIR(620);
  delayMicroseconds(480);
  pulseIR(620);
  delayMicroseconds(480);
  pulseIR(620);
  delayMicroseconds(1580);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(1600);
  pulseIR(600);
  delayMicroseconds(1580);
  pulseIR(620);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(1580);
  pulseIR(620);
  delayMicroseconds(1580);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(1600);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(1580);
  pulseIR(620);
  delayMicroseconds(480);
  pulseIR(620);
  delayMicroseconds(1580);
  pulseIR(600);
  delayMicroseconds(1600);
  pulseIR(580);
  delayMicroseconds(1600);
  pulseIR(620);
  delayMicroseconds(1580);
  pulseIR(620);
  delayMicroseconds(1580);
  pulseIR(600);
  delayMicroseconds(1600);
  pulseIR(600);
  delayMicroseconds(500);
  pulseIR(600);
  delayMicroseconds(41280);
  pulseIR(8860);
  delayMicroseconds(2160);
  pulseIR(600);
  delayMicroseconds(28524);
  pulseIR(8860);
  delayMicroseconds(2160);
  pulseIR(600);
}