From 8a7a32aaf3b852dfc025adf0b035cedb376cc196 Mon Sep 17 00:00:00 2001
From: JWGracht <jw.grachten@gmail.com>
Date: Sat, 5 Dec 2020 00:07:34 +0100
Subject: [PATCH] Update opentherm.cpp

Add support for Arduino Leonardo
---
 src/opentherm.cpp | 58 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 56 insertions(+), 2 deletions(-)

diff --git a/src/opentherm.cpp b/src/opentherm.cpp
index ccaf48e..fd43ad4 100644
--- a/src/opentherm.cpp
+++ b/src/opentherm.cpp
@@ -228,7 +228,7 @@ void OPENTHERM::_callCallback() {
   }
 }
 
-#ifdef AVR
+#if defined(__AVR_ATmega328P__) || defined(__AVR_ATmega168__) // Arduino Uno
 ISR(TIMER2_COMPA_vect) { // Timer2 interrupt
   OPENTHERM::_timerISR();
 }
@@ -280,7 +280,61 @@ void OPENTHERM::_stopTimer() {
   TIMSK2 = 0;
   sei();
 }
-#endif // END AVR
+#endif // END AVR arduino Uno
+
+#if defined(__AVR_ATmega32U4__) || defined(__AVR_ATmega16U4__) // Arduino Leonardo
+ISR(TIMER3_COMPA_vect) { // Timer3 interrupt
+  OPENTHERM::_timerISR();
+}
+
+// 5 kHz timer
+void OPENTHERM::_startReadTimer() {
+  cli();
+  TCCR3A = 0; // set entire TCCR3A register to 0
+  TCCR3B = 0; // same for TCCR3B
+  TCNT3  = 0; //initialize counter value to 0
+  // set compare match register for 4kHz increments (1/4 of bit period)
+  OCR3A = 3199; // = (16*10^6) / (5000*1) - 1 (must be <65536)
+  TCCR3B |= (1 << WGM32);  // turn on CTC mode
+  TCCR3B |= (1 << CS30);   // No prescaling
+  TIMSK3 |= (1 << OCIE3A); // enable timer compare interrupt
+  sei();
+}
+
+// 2 kHz timer
+void OPENTHERM::_startWriteTimer() {
+  cli();
+  TCCR3A = 0; // set entire TCCR3A register to 0
+  TCCR3B = 0; // same for TCCR3B
+  TCNT3  = 0; //initialize counter value to 0
+  // set compare match register for 2080Hz increments (2kHz to do transition in the middle of the bit)
+  OCR3A = 7691;// = (16*10^6) / (2080*1) - 1 (must be <65536)
+  TCCR3B |= (1 << WGM32); // turn on CTC mode
+  TCCR3B |= (1 << CS30);   // No prescaling
+  TIMSK3 |= (1 << OCIE3A); // enable timer compare interrupt
+  sei();
+}
+
+// 1 kHz timer
+void OPENTHERM::_startTimeoutTimer() {
+  cli();
+  TCCR3A = 0; // set entire TCCR3A register to 0
+  TCCR3B = 0; // same for TCCR3B
+  TCNT3  = 0; //initialize counter value to 0
+  // set compare match register for 1kHz increments
+  OCR3A = 15999; // = (16*10^6) / (1000*1) - 1 (must be <65536)
+  TCCR3B |= (1 << WGM32); // turn on CTC mode
+  TCCR3B |= (1 << CS30);   // No prescaling
+  TIMSK3 |= (1 << OCIE3A); // enable timer compare interrupt
+  sei();
+}
+
+void OPENTHERM::_stopTimer() {
+  cli();
+  TIMSK3 = 0;
+  sei();
+}
+#endif // END AVR arduino Leonardo
 
 #ifdef ESP8266
 // 5 kHz timer