initial cleanup and mapping

examples/Gertboard/7segments.c

@@ -0,0 +1,221 @@
+/*
+ * 7segments.c:
+ *	Simple test program to see if we can drive a 7-segment LED
+ *	display using the GPIO and little else on the Raspberry Pi
+ *
+ *	Copyright (c) 2013 Gordon Henderson
+ ***********************************************************************
+ */
+
+#undef	PHOTO_HACK
+
+#include <wiringPi.h>
+
+#include <stdio.h>
+#include <time.h>
+#include <ctype.h>
+#include <string.h>
+
+/*
+ *  Segment mapping
+ *
+ *	 --a--
+ *	|     |
+ *	f     b
+ *	|     |
+ *	 --g--
+ *	|     |
+ *	e     c
+ *	|     |
+ *	 --d--  p
+ */
+
+// GPIO Pin Mapping
+
+static int digits   [6] = {  7, 11, 10, 13, 12, 14    } ;
+static int segments [7] = {  6,  5,  4,  3,  2,  1, 0 } ;
+
+
+static const int segmentDigits [] =
+{
+// a  b  c  d  e  f  g     Segments
+// 6  5  4  3  2  1  0,	// wiringPi pin No.
+
+   1, 1, 1, 1, 1, 1, 0,	// 0
+   0, 1, 1, 0, 0, 0, 0,	// 1
+   1, 1, 0, 1, 1, 0, 1,	// 2
+   1, 1, 1, 1, 0, 0, 1,	// 3
+   0, 1, 1, 0, 0, 1, 1,	// 4
+   1, 0, 1, 1, 0, 1, 1,	// 5
+   1, 0, 1, 1, 1, 1, 1,	// 6
+   1, 1, 1, 0, 0, 0, 0,	// 7
+   1, 1, 1, 1, 1, 1, 1,	// 8
+   1, 1, 1, 1, 0, 1, 1,	// 9
+   1, 1, 1, 0, 1, 1, 1,	// A
+   0, 0, 1, 1, 1, 1, 1,	// b
+   1, 0, 0, 1, 1, 1, 0,	// C
+   0, 1, 1, 1, 1, 0, 1,	// d
+   1, 0, 0, 1, 1, 1, 1,	// E
+   1, 0, 0, 0, 1, 1, 1,	// F
+   0, 0, 0, 0, 0, 0, 0,	// blank
+} ;
+ 
+
+// display:
+//	A global variable which is written to by the main program and
+//	read from by the thread that updates the display. Only the first
+//	6 characters are used.
+
+char display [8] ;
+
+
+/*
+ * displayDigits:
+ *	This is our thread that's run concurrently with the main program.
+ *	Essentially sit in a loop, parsing and displaying the data held in
+ *	the "display" global.
+ *********************************************************************************
+ */
+
+PI_THREAD (displayDigits)
+{
+  int digit, segment ;
+  int index, d, segVal ;
+
+  piHiPri (50) ;
+
+  for (;;)
+  {
+    for (digit = 0 ; digit < 6 ; ++digit)
+    {
+      for (segment = 0 ; segment < 7 ; ++segment)
+      {
+	d = toupper (display [digit]) ;
+	/**/ if ((d >= '0') && (d <= '9'))	// Digit
+	  index = d - '0' ;
+	else if ((d >= 'A') && (d <= 'F'))	// Hex
+	  index = d - 'A' + 10 ;
+	else
+	  index = 16 ;				// Blank
+
+	segVal = segmentDigits [index * 7 + segment] ;
+
+	digitalWrite (segments [segment], segVal) ;
+      }
+      digitalWrite (digits [digit], 1) ;
+      delay (2) ;
+      digitalWrite (digits [digit], 0) ;
+    }
+  }
+}
+
+
+/*
+ * setup:
+ *	Initialise the hardware and start the thread
+ *********************************************************************************
+ */
+
+void setup (void)
+{
+  int i, c ;
+
+  wiringPiSetup () ;
+
+// 7 segments
+
+  for (i = 0 ; i < 7 ; ++i)
+    { digitalWrite (segments [i], 0) ; pinMode (segments [i], OUTPUT) ; }
+
+// 6 digits
+
+  for (i = 0 ; i < 6 ; ++i)
+    { digitalWrite (digits [i], 0) ;   pinMode (digits [i],   OUTPUT) ; }
+
+  strcpy (display, "      ") ;
+  piThreadCreate (displayDigits) ;
+  delay (10) ; // Just to make sure it's started
+
+// Quick countdown LED test sort of thing
+
+  c = 999999 ;
+  for (i = 0 ; i < 10 ; ++i)
+  {
+    sprintf (display, "%06d", c) ;
+    delay (400) ;
+    c -= 111111 ;
+  }
+
+  strcpy (display, "      ") ;
+  delay (400) ;
+
+#ifdef PHOTO_HACK
+  sprintf (display, "%s", "123456") ;
+  for (;;)
+    delay (1000) ;
+#endif
+
+}
+
+
+/*
+ * teenager:
+ *	No explanation needed. (Nor one given!)
+ *********************************************************************************
+ */
+
+void teenager (void)
+{
+  char *message = "      feedbeef      babe      cafe      b00b      " ;
+  int i ;
+
+  for (i = 0 ; i < strlen (message) - 4 ; ++i)
+  {
+    strncpy (display, &message [i], 6) ;
+    delay (200) ;
+  }
+  delay (1000) ;
+  for (i = 0 ; i < 3 ; ++i)
+  {
+    strcpy (display, "    ") ;
+    delay (150) ;
+    strcpy (display, " b00b ") ;
+    delay (250) ;
+  }
+  delay (1000) ;
+  strcpy (display, "      ") ;
+  delay (1000) ;
+}
+
+
+/*
+ *********************************************************************************
+ * main:
+ *	Let the fun begin
+ *********************************************************************************
+ */
+
+int main (void)
+{
+  struct tm *t ;
+  time_t     tim ;
+
+  setup    () ;
+  teenager () ;
+
+  tim = time (NULL) ;
+  for (;;)
+  {
+    while (time (NULL) == tim)
+      delay (5) ;
+
+    tim = time (NULL) ;
+    t   = localtime (&tim) ;
+
+    sprintf (display, "%02d%02d%02d", t->tm_hour, t->tm_min, t->tm_sec) ;
+
+    delay (500) ;
+  }
+
+  return 0 ;
+}