From a81393029f49e4f7b4281fe2b3413ad00a5a1f64 Mon Sep 17 00:00:00 2001
From: josh <josh@bd8a9e45-a331-0410-811e-c64571078777>
Date: Wed, 30 Apr 2008 22:54:01 +0000
Subject: [PATCH] implemented looping logic to display all three digits

git-svn-id: svn://anubis/misc/parapin-led@54 bd8a9e45-a331-0410-811e-c64571078777
---
 led.c | 39 +++++++++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/led.c b/led.c
index 3da73b5..65c65fd 100644
--- a/led.c
+++ b/led.c
@@ -1,6 +1,7 @@
 
 #include <parapin.h>
-#include <stdlib.h>
+#include <stdlib.h>         /* atoi() */
+#include <unistd.h>         /* usleep() */
 
 #define LED_A LP_PIN02
 #define LED_B LP_PIN03
@@ -19,6 +20,8 @@
 
 #define LED_ALL (LED_A | LED_B | LED_C | LED_D | LED_E | LED_F | LED_G | LED_DP | LED_1 | LED_2 | LED_3)
 
+#define DELAY 250 /* microsecond delay between displaying digits */
+
 int digit2pins[] = {
     LED_A | LED_B | LED_C | LED_D | LED_E | LED_F,
     LED_B | LED_C,
@@ -39,6 +42,7 @@ int position2pins[] = {
 };
 
 void turnOnDigit(int digitPosition, int value);
+void shutDown(int p);
 
 int main(int argc, char * argv[])
 {
@@ -50,8 +54,34 @@ int main(int argc, char * argv[])
 
     if (argc == 2)
     {
+        /* get the value to display from the command-line */
         int value = atoi(argv[1]);
-        turnOnDigit(2, value % 10);
+
+        /* register an interrupt signal handler to clear the pins */
+        signal(SIGINT, shutDown);
+
+        int digits[3];
+        register int i;
+        for (i = 0; i < 3; i++)
+        {
+            digits[2-i] = value % 10;
+            value /= 10;
+        }
+
+        /* loop displaying digits */
+        i = 0;
+        for (;;)
+        {
+            turnOnDigit(i, digits[i]);
+            usleep(DELAY);
+            i++;
+            if (i == 3)
+                i = 0;
+        }
+    }
+    else
+    {
+        clear_pin(LED_ALL);
     }
 }
 
@@ -65,3 +95,8 @@ void turnOnDigit(int digitPosition, int value)
     pinSet |= digit2pins[value];
     set_pin(pinSet);
 }
+
+void shutDown(int p)
+{
+    clear_pin(LED_ALL);
+}