Diff: main.cpp

Revision:

1:4d9d638b8e3f

Parent:

0:71cc75eb9510

--- a/main.cpp	Mon Oct 11 22:09:37 2010 +0000
+++ b/main.cpp	Tue Oct 12 22:08:37 2010 +0000
@@ -1,8 +1,20 @@
+/**************************************************************************
+***************************************************************************
+
+Countdown from 99 to 0 on a dual digit 7 segment display
+by Amos 12/10/2010 (that's October 12th!) 
+
+
+***************************************************************************
+***************************************************************************/
+
 #include "mbed.h"
 
-DigitalOut myPins[] = {p7, p8, p9, p10, p11, p12, p13};
+DigitalOut myLeftPins[] = {p7, p8, p9, p10, p11, p12, p13};
+DigitalOut myRightPins[] = {p14, p15, p16, p17, p18, p19, p20};
 
 /*
+Individual numerals
 int zero[] = {0, 0, 0, 1, 0, 0, 0};
 int one[] = {0, 1, 1, 1, 1, 1, 0};
 int two[] = {1, 0, 0, 0, 0, 1, 0};
@@ -15,6 +27,9 @@
 int nine[] = {0, 1, 0, 0, 0, 0, 0};
 */
 
+//This is an array of arrays where the first index into the array
+//locates the pin combination which displays that digit
+//eg numb[1] returns the array containg the segments to display 1.
 int numb[10][7] = {{0, 0, 0, 1, 0, 0, 0},
                 {0, 1, 1, 1, 1, 1, 0}, 
                 {1, 0, 0, 0, 0, 1, 0}, 
@@ -28,18 +43,26 @@
 
 int main()
 {
-    for(int i = 0; i < 7; i++)
-    {
-        myPins[i] = 1;
-    }
     while(1)
     {
-        for(int k = 0; k < 10; k++)
+        for(int i = 0; i < 7; i++)
         {
+            //clear all pins
+            myLeftPins[i] = 1;
+            myRightPins[i] = 1;
+        }        
+        //Countdown loop
+        for(int x = 99; x >= 0; x--)
+        {
+            //set the main counter
             for(int i = 0; i < 7; i++)
             {
-                myPins[i] = numb[k][i];            
+                //Left digit displays the value of x/10 ie the tens column
+                myLeftPins[i] = numb[x/10][i]; 
+                //Right digit displays the value of x%10 ie the units column
+                myRightPins[i] = numb[x%10][i];         
             }
+            //1 second
             wait(1);
         }
     }