Lots of changes here. Added new I2C test code, a new serialTest program,

and developed the new ISR - Interrupt Service Routine
handler - much easier than the old waitForInterrupt code!

Minor tweaks to the gpio program to recognise the environment variable
WIRINGPI_DEBUG too, and removed the printing of the errors from the
main wiringPi setup routines (and added some new ones!)

examples/Makefile

@@ -35,10 +35,10 @@ LDLIBS    = -lwiringPi
 # Should not alter anything below this line
 ###############################################################################
 
-SRC	=	test1.c test2.c speed.c lcd.c wfi.c		\
+SRC	=	test1.c test2.c speed.c lcd.c wfi.c isr.c	\
 		piface.c gertboard.c nes.c			\
 		pwm.c tone.c servo.c				\
-		delayTest.c serialRead.c okLed.c
+		delayTest.c serialRead.c serialTest.c okLed.c
 
 OBJ	=	$(SRC:.c=.o)
 
@@ -69,6 +69,10 @@ wfi:	wfi.o
 	@echo [link]
 	@$(CC) -o $@ wfi.o $(LDFLAGS) $(LDLIBS)
 
+isr:	isr.o
+	@echo [link]
+	@$(CC) -o $@ isr.o $(LDFLAGS) $(LDLIBS)
+
 piface:	piface.o
 	@echo [link]
 	@$(CC) -o $@ piface.o $(LDFLAGS) $(LDLIBS) -lpthread
@@ -93,6 +97,10 @@ serialRead:	serialRead.o
 	@echo [link]
 	@$(CC) -o $@ serialRead.o $(LDFLAGS) $(LDLIBS)
 
+serialTest:	serialTest.o
+	@echo [link]
+	@$(CC) -o $@ serialTest.o $(LDFLAGS) $(LDLIBS)
+
 okLed:	okLed.o
 	@echo [link]
 	@$(CC) -o $@ okLed.o $(LDFLAGS) $(LDLIBS)

examples/isr.c

@@ -0,0 +1,99 @@
+/*
+ * isr.c:
+ *	Wait for Interrupt test program - ISR method
+ *
+ *	How to test:
+ *	  Use the SoC's pull-up and pull down resistors that are avalable
+ *	on input pins. So compile & run this program (via sudo), then
+ *	in another terminal:
+ *		gpio mode 0 up
+ *		gpio mode 0 down
+ *	at which point it should trigger an interrupt. Toggle the pin
+ *	up/down to generate more interrupts to test.
+ *
+ * Copyright (c) 2013 Gordon Henderson.
+ ***********************************************************************
+ * This file is part of wiringPi:
+ *	https://projects.drogon.net/raspberry-pi/wiringpi/
+ *
+ *    wiringPi 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 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    wiringPi 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 wiringPi.  If not, see <http://www.gnu.org/licenses/>.
+ ***********************************************************************
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <wiringPi.h>
+
+
+// What GPIO input are we using?
+//	This is a wiringPi pin number
+
+#define	BUTTON_PIN	0
+
+// globalCounter:
+//	Global variable to count interrupts
+//	Should be declared volatile to make sure the compiler doesn't cache it.
+
+static volatile int globalCounter = 0 ;
+
+
+/*
+ * myInterrupt:
+ *********************************************************************************
+ */
+
+void myInterrupt (void)
+{
+  ++globalCounter ;
+}
+
+
+/*
+ *********************************************************************************
+ * main
+ *********************************************************************************
+ */
+
+int main (void)
+{
+  int myCounter = 0 ;
+
+  if (wiringPiSetup () < 0)
+  {
+    fprintf (stderr, "Unable to setup wiringPi: %s\n", strerror (errno)) ;
+    return 1 ;
+  }
+
+  if (wiringPiISR (BUTTON_PIN, INT_EDGE_FALLING, &myInterrupt) < 0)
+  {
+    fprintf (stderr, "Unable to setup ISR: %s\n", strerror (errno)) ;
+    return 1 ;
+  }
+
+
+  for (;;)
+  {
+    printf ("Waiting ... ") ; fflush (stdout) ;
+
+    while (myCounter == globalCounter)
+      delay (100) ;
+
+    printf (" Done. counter: %5d\n", globalCounter) ;
+    myCounter = globalCounter ;
+  }
+
+  return 0 ;
+}

examples/okLed.c

@@ -17,6 +17,7 @@
 #include <string.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <math.h>
 
 #include <wiringPi.h>
 #include <softPwm.h>

examples/serialTest.c

@@ -0,0 +1,57 @@
+/*
+ * serialTest.c:
+ *	Very simple program to test the serial port. Expects
+ *	the port to be looped back to itself
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+#include <wiringPi.h>
+#include <wiringSerial.h>
+
+int main ()
+{
+  int fd ;
+  int count ;
+  unsigned int nextTime ;
+
+  if ((fd = serialOpen ("/dev/ttyAMA0", 115200)) < 0)
+  {
+    fprintf (stderr, "Unable to open serial device: %s\n", strerror (errno)) ;
+    return 1 ;
+  }
+
+  if (wiringPiSetup () == -1)
+  {
+    fprintf (stdout, "Unable to start wiringPi: %s\n", strerror (errno)) ;
+    return 1 ;
+  }
+
+  nextTime = millis () + 300 ;
+
+  for (count = 0 ; count < 256 ; )
+  {
+    if (millis () > nextTime)
+    {
+      printf ("\nOut: %3d: ", count) ;
+      fflush (stdout) ;
+      serialPutchar (fd, count) ;
+      nextTime += 300 ;
+      ++count ;
+    }
+
+    delay (3) ;
+
+    while (serialDataAvail (fd))
+    {
+      printf (" -> %3d", serialGetchar (fd)) ;
+      fflush (stdout) ;
+    }
+  }
+
+  printf ("\n") ;
+  return 0 ;
+}

examples/wfi.c

@@ -2,7 +2,17 @@
  * wfi.c:
  *	Wait for Interrupt test program
  *
- * Copyright (c) 2012 Gordon Henderson.
+ *	This program demonstrates the use of the waitForInterrupt()
+ *	function in wiringPi. It listens to a button input on
+ *	BCM_GPIO pin 17 (wiringPi pin 0)
+ *
+ *	The biggest issue with this method is that it really only works
+ *	well in Sys mode.
+ *
+ *	Jan 2013: This way of doing things is sort of deprecated now, see
+ *	the wiringPiISR() function instead and the isr.c test program here.
+ *
+ * Copyright (c) 2012-2013 Gordon Henderson.
  ***********************************************************************
  * This file is part of wiringPi:
  *	https://projects.drogon.net/raspberry-pi/wiringpi/
@@ -33,9 +43,8 @@
 #define	COUNT_KEY	0
 
 // What BCM_GPIO input are we using?
-//	GPIO 0 is one of the I2C pins with an on-board pull-up
 
-#define	BUTTON_PIN	0
+#define	BUTTON_PIN	17
 
 // Debounce time in mS
 
@@ -63,13 +72,11 @@ PI_THREAD (waitForIt)
   int debounceTime = 0 ;
 
   (void)piHiPri (10) ;	// Set this thread to be high priority
-  digitalWrite (18, 1) ;
 
   for (;;)
   {
     if (waitForInterrupt (BUTTON_PIN, -1) > 0)	// Got it
     {
-
 // Bouncing?
 
       if (millis () < debounceTime)
@@ -80,7 +87,6 @@ PI_THREAD (waitForIt)
 
 // We have a valid one
 
-      digitalWrite (17, state) ;
       state ^= 1 ;
 
       piLock (COUNT_KEY) ;
@@ -89,7 +95,7 @@ PI_THREAD (waitForIt)
 
 // Wait for key to be released
 
-      while (digitalRead (0) == LOW)
+      while (digitalRead (BUTTON_PIN) == LOW)
 	delay (1) ;
 
       debounceTime = millis () + DEBOUNCE_TIME ;
@@ -108,11 +114,9 @@ void setup (void)
 {
 
 // Use the gpio program to initialise the hardware
-//	(This is the crude, but effective bit)
+//	(This is the crude, but effective)
 
-  system ("gpio   edge  0 falling") ;
-  system ("gpio export 17 out") ;
-  system ("gpio export 18 out") ;
+  system ("gpio edge 17 falling") ;
 
 // Setup wiringPi
 
@@ -120,9 +124,8 @@ void setup (void)
 
 // Fire off our interrupt handler
 
-  piThreadCreate   (waitForIt) ;
+  piThreadCreate (waitForIt) ;
 
-  digitalWrite (17, 0) ;
 }
 
 
@@ -147,7 +150,7 @@ int main (void)
       piLock (COUNT_KEY) ;
 	myCounter = globalCounter ;
       piUnlock (COUNT_KEY) ;
-      delay (5000) ;
+      delay (500) ;
     }
 
     printf (" Done. myCounter: %5d\n", myCounter) ;