Alpha-numeric Numbers Display

Code C - [expand]
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#include<reg51.h>
 
#define  Data_Port_Pins  (P0)
 
sbit  Register_Select_Pin  = P2^0;           
sbit  Read_Write_Pin  = P2^1;                
sbit  Enable_Pin  = P2^2;                     
 
sbit Column_1 = P1^0;     
sbit Column_2 = P1^1;
sbit Column_3 = P1^2;
sbit column_4 = P1^3;
 
sbit Row_1 = P1^4;
sbit Row_2 = P1^5;
sbit Row_3 = P1^6;
sbit Row_4 = P1^7;
 
void delay(int a)
{
   int i;
   for(i=0;i<a;i++);   
}
  /* send data */
  void LCD_Data (unsigned char Data)
  {
      Data_Port_Pins = Data;
      Register_Select_Pin=1;
      Read_Write_Pin=0;
      Enable_Pin =1;
      delay(150);
      Enable_Pin =0;
          delay(150);
  }
    
 
  /* Send command */
  void LCD_Command (unsigned char command)
  {
        Data_Port_Pins = command;
        Register_Select_Pin =0;
        Read_Write_Pin=0;
        Enable_Pin =1;
        delay (150);
        Enable_Pin =0;
            delay(150);
  }
    
    void LCD_Initialization(void)
{
 
       delay(15000);
       LCD_Command(0x30);
       delay(4500);
       LCD_Command(0x30);
       delay(300);
       LCD_Command(0x30);
       delay(650);
       LCD_Command(0x38);    //function set
       LCD_Command(0x0c);    //display on,cursor off,blink off
       LCD_Command(0x01);    //clear display
       LCD_Command(0x06);    //entry mode, set increment
}
 
 
    void Return(void)     //Return to 0 location on LCD
{
      LCD_Command(0x02);
      delay(1500);
}
 
void Port_Initialization(void)
{
    P0 = 0x00;   //used as data port for LCD
    P1 = 0x00;   //used for generating outputs and taking inputs from Keypad
    
}
 
char READ_SWITCHES(void)    
{    
    Row_1 = 0; Row_2 = 1; Row_3 = 1; Row_4 = 1;     //Test Row 1
 
    if (Column_1 == 0) { delay(10000); while (Column_1==0); return '1'; }
    if (Column_2 == 0) { delay(10000); while (Column_2==0); return '2'; }
    if (Column_3 == 0) { delay(10000); while (Column_3==0); return '3'; }
   
 
    Row_1 = 1; Row_2 = 0; Row_3 = 1; Row_3 = 1;     //Test Row B
 
    if (Column_1 == 0) { delay(10000); while (Column_1==0); return '4'; }
    if (Column_2 == 0) { delay(10000); while (Column_2==0); return '5'; }
    if (Column_3 == 0) { delay(10000); while (Column_3==0); return '6'; }
    
 
    Row_1 = 1; Row_2 = 1; Row_3 = 0; Row_4 = 1;     //Test Row C
 
    if (Column_1 == 0) { delay(10000); while (Column_1==0); return '7'; }
    if (Column_2 == 0) { delay(10000); while (Column_2==0); return '8'; }
    if (Column_3 == 0) { delay(10000); while (Column_3==0); return '9'; }
    
 
    Row_1 = 1; Row_2 = 1; Row_3 = 1; Row_4 = 0;     //Test Row D
 
    if (Column_1 == 0) { delay(10000); while (Column_1==0); return '*'; }
    if (Column_2 == 0) { delay(10000); while (Column_2==0); return '0'; }
    if (Column_3 == 0) { delay(10000); while (Column_3==0); return '#'; }
    
 
    return 'n';               // Means no key has been pressed
}
 
char get_key(void)               //get key from user
{
    char key = 'n';              //assume no key pressed
    while(key=='n')              //wait untill a key is pressed
    key = READ_SWITCHES();       //scan the keys again and again
    return key;                  //when key pressed then return its value
}
 
int main(void)
{
   char key;                // key char for keeping record of pressed key
  
   Port_Initialization();
     LCD_Initialization();               // Initilize LCD
   while(1)
   { 
     key = get_key();       // Get pressed key
     LCD_Command(0x01);        // Clear screen
     LCD_Data(key);        // Echo the key pressed to LCD
   }
}