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
+  //}
+}
+