Added in the SN3218 LED controller IC - as used in the PiGlow

so write a little test program with it too.
Updated gpio to use the sn3218 too.

examples/Makefile

@@ -42,7 +42,7 @@ SRC	=	blink.c blink8.c blink12.c					\
 		nes.c								\
 		softPwm.c softTone.c 						\
 		delayTest.c serialRead.c serialTest.c okLed.c ds1302.c		\
-		rht03.c
+		rht03.c piglow.c
 
 OBJ	=	$(SRC:.c=.o)
 
@@ -139,6 +139,10 @@ ds1302:	ds1302.o
 	@echo [link]
 	@$(CC) -o $@ ds1302.o $(LDFLAGS) $(LDLIBS)
 
+piglow:	piglow.o
+	@echo [link]
+	@$(CC) -o $@ piglow.o $(LDFLAGS) $(LDLIBS)
+
 
 .c.o:
 	@echo [CC] $<

examples/piglow.c

@@ -0,0 +1,51 @@
+/*
+ * piglow.c:
+ *	Very simple demonstration of the PiGlow board.
+ *	This uses the SN3218 directly - soon there will be a new PiGlow
+ *	devLib device which will handle the PiGlow board on a more easy
+ *	to use manner...
+ *
+ * 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 <wiringPi.h>
+#include <sn3218.h>
+
+#define	LED_BASE	533
+
+int main (void)
+{
+  int i, j ;
+
+  wiringPiSetupSys () ;
+
+  sn3218Setup (LED_BASE) ;
+
+  for (;;)
+  {
+    for (i = 0 ; i < 256 ; ++i)
+      for (j = 0 ; j < 18 ; ++j)
+	analogWrite (LED_BASE + j, i) ;
+
+    for (i = 255 ; i >= 0 ; --i)
+      for (j = 0 ; j < 18 ; ++j)
+	analogWrite (LED_BASE + j, i) ;
+  }
+}