Cleaned up ESP32 integration, reverted ESP32 ifdefs on irreceive examples.

- fixed indenting on existing code in a few places for consistency
- introduced IR_TIMER_USE_ESP32 for ifdefs within the code as per
  request
- added comments explaining what's missing for irsend support on ESP32
- IRrecvDemo.ino gets a warning before and after interrupt is enabled in
  case it causes a crash

TESTED=IoTuz ESP32 board and original 328p arduino to make sure current
code did not break.

Author: marcmerlin

IRremote.cpp

@@ -18,16 +18,17 @@
 // Whynter A/C ARC-110WD added by Francesco Meschia
 //******************************************************************************
 
-#ifndef ESP32
-#include <avr/interrupt.h>
-#endif
-
 // Defining IR_GLOBAL here allows us to declare the instantiation of global variables
 #define IR_GLOBAL
 #	include "IRremote.h"
 #	include "IRremoteInt.h"
 #undef IR_GLOBAL
 
+#ifndef IR_TIMER_USE_ESP32
+#include <avr/interrupt.h>
+#endif
+
+
 //+=============================================================================
 // The match functions were (apparently) originally MACROs to improve code speed
 //   (although this would have bloated the code) hence the names being CAPS
@@ -122,7 +123,7 @@ int  MATCH_SPACE (int measured_ticks,  int desired_us)
 // As soon as first MARK arrives:
 //   Gap width is recorded; Ready is cleared; New logging starts
 //
-#ifdef ESP32
+#ifdef IR_TIMER_USE_ESP32
 void IRTimer()
 #else
 ISR (TIMER_INTR_NAME)

boarddefs.h

@@ -39,13 +39,14 @@
 #	define BLINKLED_ON()   (PORTD |= B00000001)
 #	define BLINKLED_OFF()  (PORTD &= B11111110)
 
+// No system LED on ESP32, disable blinking
 #elif defined(ESP32)
 #	define BLINKLED        255
 #	define BLINKLED_ON()   1
 #	define BLINKLED_OFF()  1
 #else
 #	define BLINKLED        13
-	#define BLINKLED_ON()  (PORTB |= B00100000)
+#	define BLINKLED_ON()  (PORTB |= B00100000)
 #	define BLINKLED_OFF()  (PORTB &= B11011111)
 #endif
 
@@ -129,14 +130,16 @@
 
 // ATtiny84
 #elif defined(__AVR_ATtiny84__)
-  #define IR_USE_TIMER1     // tx = pin 6
+	#define IR_USE_TIMER1     // tx = pin 6
 
 //ATtiny85
 #elif defined(__AVR_ATtiny85__)
-  #define IR_USE_TIMER_TINY0   // tx = pin 1
+	#define IR_USE_TIMER_TINY0   // tx = pin 1
 
 // Arduino Duemilanove, Diecimila, LilyPad, Mini, Fio, Nano, etc
 // ATmega48, ATmega88, ATmega168, ATmega328
+#elif defined(ESP32)
+	#define IR_TIMER_USE_ESP32
 #else
 	//#define IR_USE_TIMER1   // tx = pin 9
 	#define IR_USE_TIMER2     // tx = pin 3
@@ -151,21 +154,12 @@
 //
 #if defined(IR_USE_TIMER2)
 
-#ifdef ESP32 // Used in irSend, not implemented yet (FIXME)
-#define TIMER_RESET	    1
-#define TIMER_ENABLE_PWM    1
-#define TIMER_DISABLE_PWM   Serial.println("IRsend not implemented for ESP32 yet");
-#define TIMER_ENABLE_INTR   1
-#define TIMER_DISABLE_INTR  1
-#define TIMER_INTR_NAME     1
-#else
 #define TIMER_RESET
 #define TIMER_ENABLE_PWM    (TCCR2A |= _BV(COM2B1))
 #define TIMER_DISABLE_PWM   (TCCR2A &= ~(_BV(COM2B1)))
 #define TIMER_ENABLE_INTR   (TIMSK2 = _BV(OCIE2A))
 #define TIMER_DISABLE_INTR  (TIMSK2 = 0)
 #define TIMER_INTR_NAME     TIMER2_COMPA_vect
-#endif
 
 #define TIMER_CONFIG_KHZ(val) ({ \
 	const uint8_t pwmval = SYSCLOCK / 2000 / (val); \
@@ -551,6 +545,28 @@
 
 #define TIMER_PWM_PIN        1  /* ATtiny85 */
 
+//---------------------------------------------------------
+// ESP32 (ESP8266 should likely be added here too)
+//
+
+// ESP32 has it own timer API and does not use these macros, but to avoid ifdef'ing
+// them out in the common code, they are defined to no-op. This allows the code to compile
+// (which it wouldn't otherwise) but irsend will not work until ESP32 specific code is written
+// for that -- merlin
+// As a warning, sending timing specific code from an ESP32 can be challenging if you need 100%
+// reliability because the arduino code may be interrupted and cause your sent waveform to be the
+// wrong length. This is specifically an issue for neopixels which require 800Khz resolution.
+// IR may just work as is with the common code since it's lower frequency, but if not, the other
+// way to do this on ESP32 is using the RMT built in driver like in this incomplete library below
+// https://github.com/ExploreEmbedded/ESP32_RMT
+#elif defined(IR_TIMER_USE_ESP32)
+#define TIMER_RESET	    1
+#define TIMER_ENABLE_PWM    1
+#define TIMER_DISABLE_PWM   Serial.println("IRsend not implemented for ESP32 yet");
+#define TIMER_ENABLE_INTR   1
+#define TIMER_DISABLE_INTR  1
+#define TIMER_INTR_NAME     1
+
 //---------------------------------------------------------
 // Unknown Timer
 //

examples/IRrecvDemo/IRrecvDemo.ino

@@ -8,19 +8,17 @@
 
 #include <IRremote.h>
 
-#ifdef ESP32
-int RECV_PIN = 35;
-#else
 int RECV_PIN = 11;
-#endif
 
 IRrecv irrecv(RECV_PIN);
 
 decode_results results;
 
 void setup()
 {
-  Serial.begin(115200);
+  Serial.begin(9600);
+  // In case the interrupt driver crashes on setup, give a clue
+  // to the user what's going on.
   Serial.println("Enabling IRin");
   irrecv.enableIRIn(); // Start the receiver
   Serial.println("Enabled IRin");

examples/IRrecvDump/IRrecvDump.ino

@@ -15,11 +15,7 @@
 *  You can change this to another available Arduino Pin.
 *  Your IR receiver should be connected to the pin defined here
 */
-#ifdef ESP32
-int RECV_PIN = 35;
-#else
 int RECV_PIN = 11;
-#endif
 
 IRrecv irrecv(RECV_PIN);
 

examples/IRrecvDumpV2/IRrecvDumpV2.ino

@@ -6,15 +6,15 @@
 //------------------------------------------------------------------------------
 // Tell IRremote which Arduino pin is connected to the IR Receiver (TSOP4838)
 //
-int recvPin = 35;
+int recvPin = 11;
 IRrecv irrecv(recvPin);
 
 //+=============================================================================
 // Configure the Arduino
 //
 void  setup ( )
 {
-  Serial.begin(115200);   // Status message will be sent to PC at 9600 baud
+  Serial.begin(9600);   // Status message will be sent to PC at 9600 baud
   irrecv.enableIRIn();  // Start the receiver
 }
 

irRecv.cpp

@@ -124,6 +124,8 @@ void  IRrecv::enableIRIn ( )
 {
 // Interrupt Service Routine - Fires every 50uS
 #ifdef ESP32
+	// ESP32 has a proper API to setup timers, no weird chip macros needed
+	// simply call the readable API versions :)
 	// 3 timers, choose #1, 80 divider nanosecond precision, 1 to count up
 	timer = timerBegin(1, 80, 1);
 	timerAttachInterrupt(timer, &IRTimer, 1);

irSend.cpp

@@ -54,7 +54,7 @@ void  IRsend::space (unsigned int time)
 //
 void  IRsend::enableIROut (int khz)
 {
-// FIXME: implement ESP32 support
+// FIXME: implement ESP32 support, see IR_TIMER_USE_ESP32 in boarddefs.h
 #ifndef ESP32
 	// Disable the Timer2 Interrupt (which is used for receiving IR)
 	TIMER_DISABLE_INTR; //Timer2 Overflow Interrupt