Diff: main.cpp

Revision:

2:afd0cb53867f

Parent:

1:0e26c8d5e834

--- a/main.cpp	Tue Aug 16 20:25:31 2016 +0000
+++ b/main.cpp	Fri Sep 02 19:45:41 2016 +0000
@@ -9,8 +9,12 @@
 /*test program to learn how to write code for a 4 digit, 7-segment LED display LDQ-N524R1
 The schematic for this (COMMON CATHODE) display shows the following connections
 schematic located at http://www.lumex.com/ldq-n514ri (open Specs PDF for drawing)
+The Common Cathode means that to turn on the segments of the 7-segment (including decimal point)
+you write a one to that segment.
+For this 4 digit display (LDQ-N524R1), each digit works backward--like its wired Common Anode so
+You write a ZERO to turn on the selected digit AND a ONE to turn off the digit.
 
-Pin Out wiring guide:(connect these mbed pins to display)
+Pin Out wiring guide:(connect the display pin # to XX mbed pin)
 
 CONTROL   DISPLAY Pin#  MBED Pin#
 ----------------------------------
@@ -28,8 +32,8 @@
 G               5          27
 
 There is no blanking on this display, 
-you have to write a ONE to Gnd pin for specific digit to turn it off
-Program demonstrates use of DigitalOut to control segments of 7 segment display for 4 digit display LDQ-N514R1  
+
+Program demonstrates use of DigitalOut to control segments of 7-segment display for 4 digit display LDQ-N514R1  
 Author: Cap'n Tim Johnson PE
 Retired Professor
 Wentworth Institude of Technology 
@@ -37,17 +41,19 @@
 Boston, MA
 */
 
-
-DigitalOut myled(LED1);  //used to signal where in the program "thou art".
+DigitalOut myled1(LED1);  //used as signal light to indicate where "thou art".
+DigitalOut myled2(LED2);
+DigitalOut myled3(LED3);
+DigitalOut myled4(LED4);
 
 int main() {
-//int on = 1;
-//int off = 0;
-int i = 2;  //wait time interval
+
+int i = 1;  //wait time interval
   
 //test of LED 7-segment diodes on 4 digit display
-//while(1){
- DigitalOut (p14, 0); //Turn on digit1, Most Significant Digit
+while(1){  
+ myled1 = 1;          //turns on signal light for digit 1
+ DigitalOut (p14, 0); //Turn on digit#1, Most Significant Digit
  DigitalOut (p21, 1); 
  DigitalOut (p22, 1); 
  DigitalOut (p23, 1); 
@@ -57,7 +63,9 @@
  DigitalOut (p27, 1); 
  DigitalOut (p10, 1); //decimal point
  wait (i);
+ myled1=0;            //turns off signal light for digit 1 
  
+ myled2=1;
  DigitalOut (p14, 1); //turn off digit1
  DigitalOut (p13, 0); //turn on digit2
  DigitalOut (p21, 1); 
@@ -69,7 +77,9 @@
  DigitalOut (p27, 1); 
  DigitalOut (p10, 1); //decimal point
  wait (i);
+ myled2=0;            //turns off signal light for digit 2
  
+ myled3=1;
  DigitalOut (p13, 1); //turn off digit2
  DigitalOut (p12, 0); //turn on digit3
  DigitalOut (p21, 1); 
@@ -81,7 +91,9 @@
  DigitalOut (p27, 1); 
  DigitalOut (p10, 1); //decimal point
  wait (i);
+ myled3=0;            //turns off signal light for digit 3
  
+ myled4=1;
  DigitalOut (p12, 1); //turn off digit3
  DigitalOut (p11, 0); //turn on digit4, Least Significant Digit
  DigitalOut (p21, 1); 
@@ -93,11 +105,16 @@
  DigitalOut (p27, 1); 
  DigitalOut (p10, 1); //decimal point
  wait (i);
+ myled4=0;            //turns off signal light for digit 4
  DigitalOut (p11, 1); //Turn off digit4
+ 
  //they are all off
  wait (1);
 
- myled=1;   //Signals all are about to turn on
+ myled1=1;   //Signal all are about to turn on
+ myled2=1; 
+ myled3=1; 
+ myled4=1;   //Signals all are about to turn on
  wait (1);
 
  DigitalOut (p14, 0); //Turn them all on
@@ -141,6 +158,9 @@
  DigitalOut (p11, 1);
  wait (1);
  
- myled=0;      //end of program signal
- 
-}   
\ No newline at end of file
+ myled1=0;      //end of program signal
+ myled2=0;      //end of program signal
+ myled3=0;      //end of program signal
+ myled4=0;      //end of program signal
+ }
+}