attachInterrupt() and detachInterrupt(): from Wiring, with changes to automatically enable and disable the relevant interrupt and to specify the trigger.

build/shared/lib/keywords.txt

@@ -11,6 +11,9 @@ HALF_PI	LITERAL1
 TWO_PI	LITERAL1
 LSBFIRST	LITERAL1
 MSBFIRST	LITERAL1
+CHANGE	LITERAL1
+FALLING	LITERAL1
+RISING	LITERAL1
 false	LITERAL1	
 true	LITERAL1	
 null	LITERAL1	
@@ -141,6 +144,8 @@ digitalRead	KEYWORD2
 pinMode	KEYWORD2
 analogRead	KEYWORD2
 analogWrite	KEYWORD2
+attachInterrupts	KEYWORD2
+detachInterrupts	KEYWORD2
 beginSerial	KEYWORD2
 serialWrite	KEYWORD2
 serialRead	KEYWORD2

readme.txt

@@ -47,6 +47,9 @@ UPDATES
 
 0007
 
+Added attachInterrupt() and detachInterrupt() functions for handling of
+external interrupts on pins 2 and 3.
+Implemented shiftOut() routine; see reference for details.
 Replaced avr-lib's uart routines with custom code for handling serial
 communication and modified C++ serial commands to call the C serial commands,
 saving ~1 KB of space; the code may behave slightly differently in border

targets/arduino/WInterrupts.c

@@ -0,0 +1,86 @@
+/* -*- mode: jde; c-basic-offset: 2; indent-tabs-mode: nil -*- */
+
+/*
+  Part of the Wiring project - http://wiring.uniandes.edu.co
+
+  Copyright (c) 2004-05 Hernando Barragan
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General
+  Public License along with this library; if not, write to the
+  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+  Boston, MA  02111-1307  USA
+  
+  Modified 24 November 2006 by David A. Mellis
+*/
+
+#include <inttypes.h>
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/pgmspace.h>
+#include <stdio.h>
+
+#include "WConstants.h"
+
+
+volatile static voidFuncPtr intFunc[EXTERNAL_NUM_INTERRUPTS];
+// volatile static voidFuncPtr twiIntFunc;
+
+
+void attachInterrupt(uint8_t interruptNum, void (*userFunc)(void), int mode) {
+  if(interruptNum < EXTERNAL_NUM_INTERRUPTS) {
+    intFunc[interruptNum] = userFunc;
+    
+    if (interruptNum == 0) {
+      MCUCR = (MCUCR & ~((1 << ISC00) | (1 << ISC01))) | (mode << ISC00);
+      GICR |= (1 << INT0);
+    } else {
+      MCUCR = (MCUCR & ~((1 << ISC10) | (1 << ISC11))) | (mode << ISC10);
+      GICR |= (1 << INT1);
+    }
+  }
+}
+
+void detachInterrupt(uint8_t interruptNum) {
+  if(interruptNum < EXTERNAL_NUM_INTERRUPTS) {
+    if (interruptNum == 0)
+      GICR &= ~(1 << INT0);
+    else
+      GICR &= ~(1 << INT1);
+      
+    intFunc[interruptNum] = 0;
+  }
+}
+
+/*
+void attachInterruptTwi(void (*userFunc)(void) ) {
+  twiIntFunc = userFunc;
+}
+*/
+
+SIGNAL(SIG_INTERRUPT0) {
+  if(intFunc[EXTERNAL_INT_0])
+    intFunc[EXTERNAL_INT_0]();
+}
+
+SIGNAL(SIG_INTERRUPT1) {
+  if(intFunc[EXTERNAL_INT_1])
+    intFunc[EXTERNAL_INT_1]();
+}
+
+/*
+SIGNAL(SIG_2WIRE_SERIAL) {
+  if(twiIntFunc)
+    twiIntFunc();
+}
+*/
+

targets/arduino/wiring.c

@@ -420,13 +420,14 @@ SIGNAL(SIG_OVERFLOW0)
 
 unsigned long millis()
 {
-	// timer 0 increments every 64 cycles, and overflows when it reaches 256.
-	// we would calculate the total number of clock cycles, then divide by the
-	// number of clock cycles per millisecond, but this overflows too often.
+	// timer 0 increments every 64 cycles, and overflows when it reaches
+	// 256.  we would calculate the total number of clock cycles, then
+	// divide by the number of clock cycles per millisecond, but this
+	// overflows too often.
 	//return timer0_overflow_count * 64UL * 256UL / (F_CPU / 1000UL);
 	
-  // instead find 1/128th the number of clock cycles and divide by 1/128th
-  // the number of clock cycles per millisecond
+	// instead find 1/128th the number of clock cycles and divide by
+	// 1/128th the number of clock cycles per millisecond
 	return timer0_overflow_count * 64UL * 2UL / (F_CPU / 128000UL);
 }
 
@@ -607,9 +608,9 @@ int main(void)
 	// enable a2d conversions
 	sbi(ADCSRA, ADEN);
 
-	// the bootloader connects pins 0 and 1 to the USART; disconnect them here
-	// so they can be used as normal digital i/o; they will be reconnected in
-	// Serial.begin()
+	// the bootloader connects pins 0 and 1 to the USART; disconnect them
+	// here so they can be used as normal digital i/o; they will be
+	// reconnected in Serial.begin()
 #if defined(__AVR_ATmega168__)
 	UCSR0B = 0;
 #else

targets/arduino/wiring.h

@@ -51,6 +51,10 @@ extern "C"{
 #define LSBFIRST 0
 #define MSBFIRST 1
 
+#define CHANGE 1
+#define FALLING 2
+#define RISING 3
+
 #define min(a,b) ((a)<(b)?(a):(b))
 #define max(a,b) ((a)>(b)?(a):(b))
 #define abs(x) ((x)>0?(x):-(x))
@@ -89,6 +93,9 @@ unsigned long pulseIn(int pin, int state);
 
 void shiftOut(int dataPin, int clockPin, int endianness, byte val);
 
+void attachInterrupt(uint8_t, void (*)(void), int mode);
+void detachInterrupt(uint8_t);
+
 void setup(void);
 void loop(void);
 
@@ -117,6 +124,13 @@ extern pin_t *digital_pin_to_port;
 extern pin_t *analog_in_pin_to_port;
 extern int *analog_out_pin_to_timer;
 
+#define EXTERNAL_INT_0 0
+#define EXTERNAL_INT_1 1
+
+#define EXTERNAL_NUM_INTERRUPTS 2
+
+typedef void (*voidFuncPtr)(void);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif