Need help with 4 digit 7-segment display Project

Other Hardware LEDs and Multiplexing
1

HI, i need help with a project. I want to make a countdown timer.
when i Upload the sketch to the display it's stuck on 0.0.0.0.
i want it to count down from 30min.

I'm using a Arduino MEGA 2560. with the display shown in this link:

http://arduino.fisch.lu/index.php?menu=38&page=&portal=9

This is the code am running (not mine):

int aPin = 2;  
int bPin = 3;  
int cPin = 4;  
int dPin = 5;  
int ePin = 6;  
int fPin = 7;  
int gPin = 8;  
int GND1 = 9; 
int GND2 = 10;
int GND3 = 11;
int GND4 = 12;    
int num;           
int dig1;
int dig2 = 0;
int dig3 = 0;
int dig4 = 0;
int DTime = 4;


void setup()
{
  pinMode(aPin, OUTPUT);
  pinMode(bPin, OUTPUT);
  pinMode(cPin, OUTPUT);
  pinMode(dPin, OUTPUT);
  pinMode(ePin, OUTPUT);  
  pinMode(fPin, OUTPUT);
  pinMode(gPin, OUTPUT);
  pinMode(GND1, OUTPUT);
  pinMode(GND2, OUTPUT);
  pinMode(GND3, OUTPUT);
  pinMode(GND4, OUTPUT);
  Serial.begin(9600);
}
 void loop()
{
  digitalWrite( GND1, HIGH);
  digitalWrite( GND2, HIGH);
  digitalWrite( GND3, HIGH);
  digitalWrite( GND4, HIGH);
 
 if (Serial.available() > 0) 
 {
  num = Serial.parseInt();
  Serial.println();
  dig1 = num / 1000;
  num = num - (dig1 * 1000);
  dig2 = num / 100;
  num = num - (dig2 * 100);
  dig3 = num / 10;
  dig4 = num - (dig3 *10);
 } 
  
  
  digitalWrite( GND4, LOW);    //digit 4
  pickNumber(dig4);
  delay(DTime);
  digitalWrite( GND4, HIGH);
  
  digitalWrite( GND3, LOW);    //digit 3
  pickNumber(dig3);
  delay(DTime);
  digitalWrite( GND3, HIGH);
  
  digitalWrite( GND2, LOW);   //digit 2
  pickNumber(dig2);
  delay(DTime);
  digitalWrite( GND2, HIGH);
  
  digitalWrite( GND1, LOW);   //digit 1
  pickNumber(dig1);
  delay(DTime);
  digitalWrite( GND1, HIGH);
 
}
  
void pickNumber(int x){
   switch(x){
     case 1: one(); break;
     case 2: two(); break;
     case 3: three(); break;
     case 4: four(); break;
     case 5: five(); break;
     case 6: six(); break;
     case 7: seven(); break;
     case 8: eight(); break;
     case 9: nine(); break;
     default: zero(); break;
   } 
}

void clearLEDs()
{   
  digitalWrite(  2, LOW); // A
  digitalWrite(  3, LOW); // B
  digitalWrite(  4, LOW); // C
  digitalWrite(  5, LOW); // D
  digitalWrite(  6, LOW); // E
  digitalWrite(  7, LOW); // F
  digitalWrite(  8, LOW); // G 
}

void one()
{
  digitalWrite( aPin, LOW); 
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH); 
  digitalWrite( dPin, LOW); 
  digitalWrite( ePin, LOW); 
  digitalWrite( fPin, LOW); 
  digitalWrite( gPin, LOW); 
}

void two()
{
  digitalWrite( aPin, HIGH); 
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, LOW); 
  digitalWrite( dPin, HIGH); 
  digitalWrite( ePin, HIGH); 
  digitalWrite( fPin, LOW); 
  digitalWrite( gPin, HIGH); 
}

void three()
{
  digitalWrite( aPin, HIGH); 
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH); 
  digitalWrite( dPin, HIGH); 
  digitalWrite( ePin, LOW); 
  digitalWrite( fPin, LOW); 
  digitalWrite( gPin, HIGH); 
}

void four()
{
  digitalWrite( aPin, LOW); 
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH); 
  digitalWrite( dPin, LOW); 
  digitalWrite( ePin, LOW); 
  digitalWrite( fPin, HIGH); 
  digitalWrite( gPin, HIGH); 
}

void five()
{
  digitalWrite( aPin, HIGH); 
  digitalWrite( bPin, LOW);
  digitalWrite( cPin, HIGH); 
  digitalWrite( dPin, HIGH); 
  digitalWrite( ePin, LOW); 
  digitalWrite( fPin, HIGH); 
  digitalWrite( gPin, HIGH); 
}

void six()
{
  digitalWrite( aPin, HIGH); 
  digitalWrite( bPin, LOW);
  digitalWrite( cPin, HIGH); 
  digitalWrite( dPin, HIGH); 
  digitalWrite( ePin, HIGH); 
  digitalWrite( fPin, HIGH); 
  digitalWrite( gPin, HIGH); 
}

void seven()
{
  digitalWrite( aPin, HIGH); 
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH); 
  digitalWrite( dPin, LOW); 
  digitalWrite( ePin, LOW); 
  digitalWrite( fPin, LOW); 
  digitalWrite( gPin, LOW); 
}

void eight()
{
  digitalWrite( aPin, HIGH); 
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH); 
  digitalWrite( dPin, HIGH); 
  digitalWrite( ePin, HIGH); 
  digitalWrite( fPin, HIGH); 
  digitalWrite( gPin, HIGH); 
}

void nine()
{
  digitalWrite( aPin, HIGH); 
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH); 
  digitalWrite( dPin, HIGH); 
  digitalWrite( ePin, LOW); 
  digitalWrite( fPin, HIGH); 
  digitalWrite( gPin, HIGH); 
}

void zero()
{
  digitalWrite( aPin, HIGH); 
  digitalWrite( bPin, HIGH);
  digitalWrite( cPin, HIGH); 
  digitalWrite( dPin, HIGH); 
  digitalWrite( ePin, HIGH); 
  digitalWrite( fPin, HIGH); 
  digitalWrite( gPin, LOW); 
}
2

There is code for a countdown timer in my repository, link below. This could be useful as a model.

3

The code is a bit of a mess, but:

  1. You never call clearLEDs();
  2. num never gets decremented after the initial setting.

Try setting num to 1234 in the initializer to see if your led code is working correctly.

i.e.:

int num=1234;

Investigate the millis() function, then in the loop, if num > 0, decrement the num based on the change in millis() since last time through the loop (or since the first time through the loop).

4

Can someone send me sketch for a countdown timer with 4 digits that works?
I am new to programing and arduino and have no clue.

would be greatly appreciated.

5

Can someone send me sketch for a countdown timer with 4 digits that works?

Read my previous post