Infrared remote library for Arduino: send and receive infrared signals with multiple protocols Port from Arduino-IRremote https://github.com/z3t0/Arduino-IRremote
Diff: irSend.cpp
- Revision:
- 0:70c8e56bac45
- Child:
- 3:17440cf7ab90
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/irSend.cpp Sat Jan 23 06:16:48 2016 +0000 @@ -0,0 +1,87 @@ +#include "IRremote.h" +#include "IRremoteInt.h" + +//+============================================================================= +void IRsend::sendRaw (unsigned int buf[], unsigned int len, unsigned int hz) +{ + // Set IR carrier frequency + enableIROut(hz); + + for (unsigned int i = 0; i < len; i++) { + if (i & 1) space(buf[i]) ; + else mark (buf[i]) ; + } + + space(0); // Always end with the LED off +} + +//+============================================================================= +// Sends an IR mark for the specified number of microseconds. +// The mark output is modulated at the PWM frequency. +// +void IRsend::mark (unsigned int time) +{ + TIMER_ENABLE_PWM; // Enable pin 3 PWM output + if (time > 0) custom_delay_usec(time); +} + +//+============================================================================= +// Leave pin off for time (given in microseconds) +// Sends an IR space for the specified number of microseconds. +// A space is no output, so the PWM output is disabled. +// +void IRsend::space (unsigned int time) +{ + TIMER_DISABLE_PWM; // Disable pin 3 PWM output + if (time > 0) IRsend::custom_delay_usec(time); +} + + + + + +//+============================================================================= +// 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); +} + +//+============================================================================= +// Custom delay function that circumvents Arduino's delayMicroseconds limit + +void IRsend::custom_delay_usec(unsigned long uSecs) { + if (uSecs > 4) { + unsigned long start = micros(); + unsigned long endMicros = start + uSecs - 4; + if (endMicros < start) { // Check if overflow + while ( micros() > start ) {} // wait until overflow + } + while ( micros() < endMicros ) {} // normal wait + } + //else { + // __asm__("nop\n\t"); // must have or compiler optimizes out + //} +} +