Saturday, 30 May 2015

Seven Segment LED display with Arduino and Proteus

In a simpler view seven segment led display have seven led's with their combination we can display decimal numerals.

when connecting a common cathode in a proteus i have no idea which pin is associated to the respective led in display so i write a little code to do that work for me.

Code :
/*
Arduino Sketch to find out which pin is Associated with corresponding LED in 7 segment display
Author : Kunchala Anil

 It is a common cathode 7 Segment Display.
 connect the common cathode to ground and all the remaining pins to the Arduino Digital pins 2 to 8
 */

int pin = 2;
int pin_dummy = 2;
void setup()
{
  Serial.begin(9600);
  Serial.println("Hello World");
  for(int i = 2; i <= 8; i++)
  {
    pinMode(i,OUTPUT);
    Serial.print("pin \t");
    Serial.print(i);
    Serial.println("\t is set as Output");
  }//end of for loop

}//end of setup

void loop()
{
  Serial.println("Please enter y");
  while(!Serial.available())
  {
    //wait until user enters the data
  }//end of while
  if(Serial.available())
  {
    if(Serial.read() == 'y')
    {
      if(pin_dummy <= 8)
      {
        digitalWrite(pin_dummy,LOW);
        Serial.println("you entered y");
        digitalWrite(pin,HIGH);
        Serial.print("pin ");
        Serial.print(pin);
        Serial.println(" is activated");
        pin_dummy = pin; // pin_dummy is used to OFF the LED before ON next led in display
        pin++;
      }
      else{
        Serial.println("Maximum pin number is reached");
        pin = 2;
        pin_dummy =2;
        Serial.println("Pin values are RESET");
      }//end of If else

    }
    else{
      Serial.println("you entered wrong character");
    }//end of If Else 
  }//end of If 

}//end of loop

after executing the above code i get the following combination
GFEDCBA for 2,3,4,5,6,7,8 pins respectively.
The following code is used to display the 0-9 in common cathode seven segment display.

/*
hEXA DECIMAL ENCODING FOR DISPLAYING NUMBERS 0 TO 9
 FOR COMBINATION - GFEDCBA to pins 2,3,4,5,6,7,8 
 */
/*
 Hex codes for displayiing respective values
 */
const int ZERO = 0X7E;
const int ONE = 0X30;
const int TWO = 0X6D;
const int  THREE = 0X79;
const int  FOUR = 0X33;
const int  FIVE = 0X5B;
const int  SIX = 0X5F;
const int  SEVEN = 0X70;
const int   EIGHT = 0X7F;
const int  NINE = 0X7B;

//pins initialization
int pin[] = {
  2,3,4,5,6,7,8};

//calculating the no of pins
int no_pins = sizeof(pin)/sizeof(pin[0]);


void setup(){
  Serial.begin(9600);
  //setting all pins as Outputs
  for(int i = 0; i < no_pins;i++)
  {
    pinMode(pin[i],OUTPUT);

  }//end of for loop
}//end of setup


void loop(){
  for(int i=0;i<=9;i++)
  {
    switch(i)
    {
    case 0:
      display_it(ZERO);
      break;

    case 1:
      display_it(ONE);
      break;

    case 2:
      display_it(TWO);
      break;

    case 3:
      display_it(THREE);
      break;

    case 4:
      display_it(FOUR);
      break;

    case 5:
      display_it(FIVE);
      break;

    case 6:
      display_it(SIX);
      break;

    case 7:
      display_it(SEVEN);
      break;

    case 8:
      display_it(EIGHT);
      break;

    case 9:
      display_it(NINE);
      break;

    default :
      Serial.println("something went wrong");

    }//end of switch
  }//end of for loop()
}//end of loop


void display_it(const int value)
{
  for(int i=2,j=0;i<=8;i++,j++)
  {
    digitalWrite(i,bitRead(value,j));

  }
  delay(1000);
}

Proteus Schematic is :









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