void IRsend::enableIROut(int khz) {
// Enables IR output. The khz value controls the modulation frequency in kilohertz.
// The IR output will be on pin 3 (OC2B).
// This routine is designed for 36-40KHz; if you use it for other values, it's up to you
// to make sure it gives reasonable results. (Watch out for overflow / underflow / rounding.)
// TIMER2 is used in phase-correct PWM mode, with OCR2A controlling the frequency and OCR2B
// controlling the duty cycle.
// There is no prescaling, so the output frequency is 16MHz / (2 * OCR2A)
// To turn the output on and off, we leave the PWM running, but connect and disconnect the output pin.
// A few hours staring at the ATmega documentation and this will all make sense.
// See my Secrets of Arduino PWM at http://arcfn.com/2009/07/secrets-of-arduino-pwm.html for details.
// Disable the Timer2 Interrupt (which is used for receiving IR)
TIMER_DISABLE_INTR; //Timer2 Overflow Interrupt
pinMode(TIMER_PWM_PIN, OUTPUT);
digitalWrite(TIMER_PWM_PIN, LOW); // When not sending PWM, we want it low
// COM2A = 00: disconnect OC2A
// COM2B = 00: disconnect OC2B; to send signal set to 10: OC2B non-inverted
// WGM2 = 101: phase-correct PWM with OCRA as top
// CS2 = 000: no prescaling
// The top value for the timer. The modulation frequency will be SYSCLOCK / 2 / OCR2A.
TIMER_CONFIG_KHZ(khz);
}
//+=============================================================================
// Enables IR output. The khz value controls the modulation frequency in kilohertz.
// The IR output will be on pin 3 (OC2B).
// This routine is designed for 36-40KHz; if you use it for other values, it's up to you
// to make sure it gives reasonable results. (Watch out for overflow / underflow / rounding.)
// TIMER2 is used in phase-correct PWM mode, with OCR2A controlling the frequency and OCR2B
// controlling the duty cycle.
// There is no prescaling, so the output frequency is 16MHz / (2 * OCR2A)
// To turn the output on and off, we leave the PWM running, but connect and disconnect the output pin.
// A few hours staring at the ATmega documentation and this will all make sense.
// See my Secrets of Arduino PWM at http://arcfn.com/2009/07/secrets-of-arduino-pwm.html for details.
//
void IRsend::enableIROut (int khz)
{
// Disable the Timer2 Interrupt (which is used for receiving IR)
TIMER_DISABLE_INTR; //Timer2 Overflow Interrupt
pinMode(TIMER_PWM_PIN, OUTPUT);
digitalWrite(TIMER_PWM_PIN, LOW); // When not sending PWM, we want it low
// COM2A = 00: disconnect OC2A
// COM2B = 00: disconnect OC2B; to send signal set to 10: OC2B non-inverted
// WGM2 = 101: phase-correct PWM with OCRA as top
// CS2 = 000: no prescaling
// The top value for the timer. The modulation frequency will be SYSCLOCK / 2 / OCR2A.
TIMER_CONFIG_KHZ(khz);
}
/*
* The hardware specific portions of IRsendBase
*/
void IRsendBase::enableIROut(unsigned char khz) {
//NOTE: the comments on this routine accompanied the original early version of IRremote library
//which only used TIMER2. The parameters defined in IRLibTimer.h may or may not work this way.
// Enables IR output. The khz value controls the modulation frequency in kilohertz.
// The IR output will be on pin 3 (OC2B).
// This routine is designed for 36-40KHz; if you use it for other values, it's up to you
// to make sure it gives reasonable results. (Watch out for overflow / underflow / rounding.)
// TIMER2 is used in phase-correct PWM mode, with OCR2A controlling the frequency and OCR2B
// controlling the duty cycle.
// There is no prescaling, so the output frequency is 16MHz / (2 * OCR2A)
// To turn the output on and off, we leave the PWM running, but connect and disconnect the output pin.
// A few hours staring at the ATmega documentation and this will all make sense.
// See my Secrets of Arduino PWM at http://www.righto.com/2009/07/secrets-of-arduino-pwm.html for details.
// Disable the Timer2 Interrupt (which is used for receiving IR)
TIMER_DISABLE_INTR; //Timer2 Overflow Interrupt
pinMode(TIMER_PWM_PIN, OUTPUT);
digitalWrite(TIMER_PWM_PIN, LOW); // When not sending PWM, we want it low
TIMER_CONFIG_KHZ(khz);
}
