Serial attach interrupt

cores/arduino/HardwareSerial.cpp

@@ -20,6 +20,8 @@
   Modified 28 September 2010 by Mark Sproul
   Modified 14 August 2012 by Alarus
   Modified 3 December 2013 by Matthijs Kooijman
+  Modified 2 November 2015 by SlashDev
+  Modified 23 November 2019 by Georg Icking-Konert
 */
 
 #include <stdlib.h>
@@ -84,6 +86,9 @@ void serialEventRun(void)
 #define TX_BUFFER_ATOMIC
 #endif
 
+// dummy custom function for TxC interrupt. Is faster than check if(fct==NULL) 
+void dummyTxFct(void) { /* dummy */}
+
 // Actual interrupt handlers //////////////////////////////////////////////////////////////
 
 void HardwareSerial::_tx_udr_empty_irq(void)
@@ -147,6 +152,7 @@ void HardwareSerial::begin(unsigned long baud, byte config)
   sbi(*_ucsrb, TXEN0);
   sbi(*_ucsrb, RXCIE0);
   cbi(*_ucsrb, UDRIE0);
+  //cbi(*_ucsrb, TXCIE0);
 }
 
 void HardwareSerial::end()
@@ -158,6 +164,7 @@ void HardwareSerial::end()
   cbi(*_ucsrb, TXEN0);
   cbi(*_ucsrb, RXCIE0);
   cbi(*_ucsrb, UDRIE0);
+  cbi(*_ucsrb, TXCIE0);
 
   // clear any received data
   _rx_buffer_head = _rx_buffer_tail;
@@ -278,4 +285,30 @@ size_t HardwareSerial::write(uint8_t c)
   return 1;
 }
 
+void HardwareSerial::attachInterrupt_Receive( isrRx_t fn, void* args )
+{
+  uint8_t oldSREG = SREG;
+  cli();
+  _isrRx = fn;
+  _rxArg = args;
+  SREG = oldSREG;
+}
+
+void HardwareSerial::attachInterrupt_Send( isrTx_t fn )
+{
+  ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+    _isrTx = fn;             // set custom function
+    sbi(*_ucsra, TXC0);      // clear TXC status
+    sbi(*_ucsrb, TXCIE0);    // activate TXC interrupt
+  }
+}
+
+void HardwareSerial::detachInterrupt_Send()
+{
+  ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
+    _isrTx = dummyTxFct;     // restore dummy function
+    cbi(*_ucsrb, TXCIE0);    // deactivate TXC interrupt
+  }
+}
+
 #endif // whole file

cores/arduino/HardwareSerial.h

@@ -19,6 +19,8 @@
   Modified 28 September 2010 by Mark Sproul
   Modified 14 August 2012 by Alarus
   Modified 3 December 2013 by Matthijs Kooijman
+  Modified 2 November 2015 by SlashDev
+  Modified 23 November 2019 by Georg Icking-Konert
 */
 
 #ifndef HardwareSerial_h
@@ -90,6 +92,9 @@ typedef uint8_t rx_buffer_index_t;
 #define SERIAL_7O2 0x3C
 #define SERIAL_8O2 0x3E
 
+// dummy custom function for TxC interrupt. Is faster than check if(fct==NULL) 
+void dummyTxFct(void);
+
 class HardwareSerial : public Stream
 {
   protected:
@@ -112,6 +117,13 @@ class HardwareSerial : public Stream
     // instruction.
     unsigned char _rx_buffer[SERIAL_RX_BUFFER_SIZE];
     unsigned char _tx_buffer[SERIAL_TX_BUFFER_SIZE];
+
+    // custom handlers for RX and TXC interrupts 
+    typedef void (* isrRx_t)( uint8_t data, uint8_t status, void* args );
+    typedef void (* isrTx_t)( void );
+    isrRx_t  _isrRx;
+    isrTx_t  _isrTx;
+    void*    _rxArg;
 
   public:
     inline HardwareSerial(
@@ -137,6 +149,18 @@ class HardwareSerial : public Stream
     // Interrupt handlers - Not intended to be called externally
     inline void _rx_complete_irq(void);
     void _tx_udr_empty_irq(void);
+    inline void _tx_complete_irq(void);
+
+    // attach custom handlers for RX and TXC interrupts 
+    void attachInterrupt_Receive( isrRx_t fn, void *args = NULL );
+    void detachInterrupt_Receive( void ) { attachInterrupt_Receive( (isrRx_t) NULL ); };
+    void attachInterrupt_Send( isrTx_t fn );
+    void detachInterrupt_Send( void );
+
+  private:
+
+    HardwareSerial( const HardwareSerial & );
+    HardwareSerial & operator =( const HardwareSerial &);
 };
 
 #if defined(UBRRH) || defined(UBRR0H)

cores/arduino/HardwareSerial0.cpp

@@ -20,6 +20,7 @@
   Modified 28 September 2010 by Mark Sproul
   Modified 14 August 2012 by Alarus
   Modified 3 December 2013 by Matthijs Kooijman
+  Modified 23 November 2019 by Georg Icking-Konert
 */
 
 #include "Arduino.h"
@@ -64,6 +65,19 @@ ISR(USART_UDRE_vect)
   Serial._tx_udr_empty_irq();
 }
 
+#if defined(UART0_TX_vect)
+ISR(UART0_TX_vect)
+#elif defined(USART0_TX_vect)
+ISR(USART0_TX_vect)
+#elif defined(USART_TX_vect)
+ISR(USART_TX_vect)
+#else
+  #error "Don't know what the Transmission Complete vector is called for Serial"
+#endif
+{
+  Serial._tx_complete_irq();
+}
+
 #if defined(UBRRH) && defined(UBRRL)
   HardwareSerial Serial(&UBRRH, &UBRRL, &UCSRA, &UCSRB, &UCSRC, &UDR);
 #else

cores/arduino/HardwareSerial1.cpp

@@ -20,6 +20,7 @@
   Modified 28 September 2010 by Mark Sproul
   Modified 14 August 2012 by Alarus
   Modified 3 December 2013 by Matthijs Kooijman
+  Modified 23 November 2019 by Georg Icking-Konert
 */
 
 #include "Arduino.h"
@@ -58,6 +59,17 @@ ISR(USART1_UDRE_vect)
   Serial1._tx_udr_empty_irq();
 }
 
+#if defined(UART1_TX_vect)
+ISR(UART1_TX_vect)
+#elif defined(USART1_TX_vect)
+ISR(USART1_TX_vect)
+#else
+  #error "Don't know what the Transmission Complete vector is called for Serial1"
+#endif
+{
+  Serial1._tx_complete_irq();
+}
+
 HardwareSerial Serial1(&UBRR1H, &UBRR1L, &UCSR1A, &UCSR1B, &UCSR1C, &UDR1);
 
 // Function that can be weakly referenced by serialEventRun to prevent

cores/arduino/HardwareSerial2.cpp

@@ -20,6 +20,7 @@
   Modified 28 September 2010 by Mark Sproul
   Modified 14 August 2012 by Alarus
   Modified 3 December 2013 by Matthijs Kooijman
+  Modified 23 November 2019 by Georg Icking-Konert
 */
 
 #include "Arduino.h"
@@ -46,6 +47,11 @@ ISR(USART2_UDRE_vect)
   Serial2._tx_udr_empty_irq();
 }
 
+ISR(USART2_TX_vect)
+{
+  Serial2._tx_complete_irq();
+}
+
 HardwareSerial Serial2(&UBRR2H, &UBRR2L, &UCSR2A, &UCSR2B, &UCSR2C, &UDR2);
 
 // Function that can be weakly referenced by serialEventRun to prevent

cores/arduino/HardwareSerial3.cpp

@@ -20,6 +20,7 @@
   Modified 28 September 2010 by Mark Sproul
   Modified 14 August 2012 by Alarus
   Modified 3 December 2013 by Matthijs Kooijman
+  Modified 23 November 2019 by Georg Icking-Konert
 */
 
 #include "Arduino.h"
@@ -46,6 +47,11 @@ ISR(USART3_UDRE_vect)
   Serial3._tx_udr_empty_irq();
 }
 
+ISR(USART3_TX_vect)
+{
+  Serial3._tx_complete_irq();
+}
+
 HardwareSerial Serial3(&UBRR3H, &UBRR3L, &UCSR3A, &UCSR3B, &UCSR3C, &UDR3);
 
 // Function that can be weakly referenced by serialEventRun to prevent

cores/arduino/HardwareSerial_private.h

@@ -19,6 +19,8 @@
   Modified 23 November 2006 by David A. Mellis
   Modified 28 September 2010 by Mark Sproul
   Modified 14 August 2012 by Alarus
+  Modified 2 November 2015 by SlashDev
+  Modified 23 November 2019 by Georg Icking-Konert
 */
 
 #include "wiring_private.h"
@@ -92,32 +94,50 @@ HardwareSerial::HardwareSerial(
     _ucsra(ucsra), _ucsrb(ucsrb), _ucsrc(ucsrc),
     _udr(udr),
     _rx_buffer_head(0), _rx_buffer_tail(0),
-    _tx_buffer_head(0), _tx_buffer_tail(0)
+    _tx_buffer_head(0), _tx_buffer_tail(0),
+    _isrRx(NULL), _isrTx(dummyTxFct), _rxArg(NULL)
 {
 }
 
 // Actual interrupt handlers //////////////////////////////////////////////////////////////
 
 void HardwareSerial::_rx_complete_irq(void)
 {
-  if (bit_is_clear(*_ucsra, UPE0)) {
-    // No Parity error, read byte and store it in the buffer if there is
-    // room
-    unsigned char c = *_udr;
-    rx_buffer_index_t i = (unsigned int)(_rx_buffer_head + 1) % SERIAL_RX_BUFFER_SIZE;
-
-    // if we should be storing the received character into the location
-    // just before the tail (meaning that the head would advance to the
-    // current location of the tail), we're about to overflow the buffer
-    // and so we don't write the character or advance the head.
-    if (i != _rx_buffer_tail) {
-      _rx_buffer[_rx_buffer_head] = c;
-      _rx_buffer_head = i;
-    }
-  } else {
-    // Parity error, read byte but discard it
-    *_udr;
-  };
+  // user receive function was attached -> call it with data, status byte and optional argument pointer 
+  if (_isrRx) {
+    unsigned char status = *_ucsra;
+    unsigned char data = *_udr;
+    _isrRx( data, status, _rxArg );
+  }
+
+  // default: save data in ring buffer
+  else {  
+    if (bit_is_clear(*_ucsra, UPE0)) {
+      unsigned char c = *_udr;
+      // No Parity error, read byte and store it in the buffer if there is
+      // room
+      rx_buffer_index_t i = (unsigned int)(_rx_buffer_head + 1) % SERIAL_RX_BUFFER_SIZE;
+
+      // if we should be storing the received character into the location
+      // just before the tail (meaning that the head would advance to the
+      // current location of the tail), we're about to overflow the buffer
+      // and so we don't write the character or advance the head.
+      if (i != _rx_buffer_tail) {
+        _rx_buffer[_rx_buffer_head] = c;
+        _rx_buffer_head = i;
+      }
+    } 
+    else {
+      // Parity error, read byte but discard it
+      *_udr;
+    };
+  }
+}
+
+void HardwareSerial::_tx_complete_irq(void)
+{
+  // user send function was attached -> call it
+  _isrTx();
 }
 
 #endif // whole file