Closed Captioning and IR Transmitter?

I’m working on a project that combines the Video Experimenter Shield’s closed captioning example and Adafruit’s IR code transmitting example so that when a certain keyword comes over closed captioning, the MUTE signal is sent to the TV.

I’ve modified the closed captioning example so that an alert is sent via serial when one of five keywords is mentioned. I’ve modified Adafruit’s example so that it sends the mute IR signal to my TV. Both sketches work independently. However, when I try to combine the examples, I get the serial alert that a keyword is mentioned, but the TV isn’t muting, leading me to believe that the timing on the IR pulses is off. Since my understanding of C code is limited to basic procedural programming, I’m wondering if there’s something going on the the background of the closed captioning example that’s throwing the timing off in the transmission of the proper IR signal. For example, take a look at the pulseIR() function in the IR code, which sends pulses for the duration of n microseconds at 38kHz (as required by many IR receivers):

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(IRledPin, HIGH);  // this takes about 3 microseconds to happen

delayMicroseconds(10);         // hang out for 10 microseconds

digitalWrite(IRledPin, LOW);   // this also takes about 3 microseconds

delayMicroseconds(10);         // hang out for 10 microseconds



// so 26 microseconds altogether

microsecs -= 26;

}



sei();  // this turns them back on

}

Am I on the right track here? Would adjusting the timing on this help me? Or should I be troubleshooting elsewhere? I’m not expecting anyone to pore over my entire sketch, but I’ll make it available through this link if it would be helpful to solve the problem.

I appreciate the help,
Matt Richardson