I am programming Intel 8052 microcontroller in C.

As you can see i am programming a LCD driver out of cascaded 595 chip. For my schematic i only drew Com1, but the rest is the same and QA-QH =A-DOT.

For the time being, my problem is to make my code work with printf, putchar and translation table. I believe i understand most about multiplexing so i would need more advises on programming.

For later phase of my project i will need program out something similar to how lcd driver should be programmed.

For example my project should be able to configure limitation of count 0000-9999 using “>” and “^” button. The digit should keep blinking whenever the digit is pointed. Save it to eeprom after setting to some value. (Blinker function)

I didn’t implement the Display RAM in my code and read function as i have no idea how. I did have ideas on how to program on all the lcd functions but I need more guidance to do that.

Schematic
http://i67.photobucket.com/albums/h3...ng/LCD.jpg
App note
www.electrosnab.ru/silabs/pdf/An_Soft/an202.pdf

#include <REG52.h>
#include <stdlib.h>
#include <stdio.h>

#define TIMER0_COUNT 0xDC11 /* 10000h - ((11,059,200 Hz / (12 * FREQ)) - 17) */

void address(unsigned char ad);
void write(unsigned char id);
void convert(unsigned char asc);
char putchar(char charIN);
unsigned char a,b,c,d,e,f,g,o,i;
unsigned int seg_count=0;

unsigned char bdata LCD_digits[7];

sbit D0A = LCD_digits[0] ^ 0;
sbit D0B = LCD_digits[0] ^ 1; // D1 is controlled by S1 and S2
sbit D0C = LCD_digits[0] ^ 2;
sbit D0D = LCD_digits[0] ^ 3;
sbit D0E = LCD_digits[0] ^ 4;
sbit D0F = LCD_digits[0] ^ 5;
sbit D0G = LCD_digits[0] ^ 6;
sbit D0O = LCD_digits[0] ^ 7;
	
sbit D1A = LCD_digits[1] ^ 0; // D2 is controlled by S3 and S4
sbit D1B = LCD_digits[1] ^ 1;
sbit D1C = LCD_digits[1] ^ 2;
sbit D1D = LCD_digits[1] ^ 3;
sbit D1E = LCD_digits[1] ^ 4;
sbit D1F = LCD_digits[1] ^ 5;
sbit D1G = LCD_digits[1] ^ 6;
sbit D1O = LCD_digits[1] ^ 7;

sbit D2A = LCD_digits[2] ^ 0; // D3 is controlled by S5 and S6
sbit D2B = LCD_digits[2] ^ 1;
sbit D2C = LCD_digits[2] ^ 2;
sbit D2D = LCD_digits[2] ^ 3;
sbit D2E = LCD_digits[2] ^ 4;
sbit D2F = LCD_digits[2] ^ 5;
sbit D2G = LCD_digits[2] ^ 6;
sbit D2O = LCD_digits[2] ^ 7;

sbit D3A = LCD_digits[3] ^ 0; // D4 is controlled by S7 and S8
sbit D3B = LCD_digits[3] ^ 1;
sbit D3C = LCD_digits[3] ^ 2;
sbit D3D = LCD_digits[3] ^ 3;
sbit D3E = LCD_digits[3] ^ 4;
sbit D3F = LCD_digits[3] ^ 5;
sbit D3G = LCD_digits[3] ^ 6;
sbit D3O = LCD_digits[3] ^ 7;

sbit D4A = LCD_digits[4] ^ 0; // D5 is controlled by S9 and S10
sbit D4B = LCD_digits[4] ^ 1;
sbit D4C = LCD_digits[4] ^ 2;
sbit D4D = LCD_digits[4] ^ 3;
sbit D4E = LCD_digits[4] ^ 4;
sbit D4F = LCD_digits[4] ^ 5;
sbit D4G = LCD_digits[4] ^ 6;
sbit D4O = LCD_digits[4] ^ 7;

sbit D5A = LCD_digits[5] ^ 0; // D6 is controlled by S11 and S12
sbit D5B = LCD_digits[5] ^ 1;
sbit D5C = LCD_digits[5] ^ 2;
sbit D5D = LCD_digits[5] ^ 3;
sbit D5E = LCD_digits[5] ^ 4;
sbit D5F = LCD_digits[5] ^ 5;
sbit D5G = LCD_digits[5] ^ 6;
sbit D5O = LCD_digits[5] ^ 7;

sbit D6A = LCD_digits[6] ^ 0; // D6 is controlled by S11 and S12
sbit D6B = LCD_digits[6] ^ 1;
sbit D6C = LCD_digits[6] ^ 2;
sbit D6D = LCD_digits[6] ^ 3;
sbit D6E = LCD_digits[6] ^ 4;
sbit D6F = LCD_digits[6] ^ 5;
sbit D6G = LCD_digits[6] ^ 6;
sbit D6O = LCD_digits[6] ^ 7;

sbit D7A = LCD_digits[7] ^ 0; // D6 is controlled by S11 and S12
sbit D7B = LCD_digits[7] ^ 1;
sbit D7C = LCD_digits[7] ^ 2;
sbit D7D = LCD_digits[7] ^ 3;
sbit D7E = LCD_digits[7] ^ 4;
sbit D7F = LCD_digits[7] ^ 5;
sbit D7G = LCD_digits[7] ^ 6;
sbit D7O = LCD_digits[7] ^ 7;

const unsigned char code translation_table[128]={	
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 0 - 7;clear
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 8 - 15;clear
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 16 - 23;clear
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 24 - 31;clear
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 32 - 39;clear
0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x01, 0x00, // 40 - 47;clear
0xFC, 0x60, 0xDA, 0xF2, 0x66, 0xB6, 0xBE, 0xE0, // 48 - 55;clear
0xFE, 0xF6, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 56 - 63;clear
0x00, 0xee, 0x3e, 0x9C, 0x7A, 0x9e, 0x8e, 0xf6, // 64 - 71;clear
0x6E, 0x60, 0x70, 0xae, 0x1C, 0x00, 0x2A, 0x3A, // 72 - 79;clear
0xce, 0xe6, 0x0A, 0xb6, 0xe0, 0x7c, 0x00, 0x00, // 80 - 87;clear
0x00, 0x76, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 88 - 95;clear
0x00, 0xee, 0x3e, 0x9C, 0x7A, 0x9e, 0x8e, 0xf6, // 96 - 103;clear
0x6E, 0x60, 0x70, 0xae, 0x1C, 0x00, 0x2A, 0x3A, // 104 - 111;clear
0xce, 0xe6, 0x0A, 0xb6, 0xe0, 0x7c, 0x00, 0x00, // 112 - 119;clear
0x00, 0x76, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // 120 - 127;clear
};

static void timer0_isr (void) interrupt 1 using 1//highest priority
{
unsigned i;
TR0 = 0; 
i = TIMER0_COUNT + TL0 + (TH0<<8);
TL0 = i;
TH0 = i >> 8;
TR0 = 1;

if(seg_count==0)				 
{	  							  //remove switch case;to if else latency
     address(0x01);
	 write(LCD_digits[0]);
	 seg_count=1; 
}
if(seg_count==1)
{
     address(0x02);
	 write(LCD_digits[1]);
	 seg_count=2; 
}

if(seg_count==2)
{
      address(0x04);
	  write(LCD_digits[2]);
	  seg_count=3; 
}

if(seg_count==3)
{
      address(0x08);
	  write(LCD_digits[3]);
	  seg_count=4; 
}
if(seg_count==4)
{
     address(0x10);
	  write(LCD_digits[4]);
	  seg_count=5; 
}
if(seg_count==5)
{
 	  address(0x20);
	  write(LCD_digits[5]);
	 seg_count=6; 
}

if(seg_count==6)
{
     address(0x40);
	 write(LCD_digits[6]);
	 seg_count=7; 
}

if(seg_count==7)
{
     address(0x80);
	 write(LCD_digits[7]);
	 seg_count=0; 
}
 
}

void convert(unsigned char asc)
{
if(asc=='~'){a=0x20;return;}
if(asc=='!'){a=0x10;return;}
if(asc=='@'){a=0x08;return;}
if(asc=='#'){a=0x04;return;}
if(asc=='$'){a=0x02;return;}
if(asc=='%'){a=0x01;return;}
if(asc=='^'){a=0x80;return;}
if(asc=='&'){a=0x40;return;}

if(asc=='+'){a=0xFD;return;}
if(asc==' '){a=0x00;return;}
if(asc=='-'){a=0x02;return;}
if(asc=='.'){a=0x01;return;}
if(asc=='0'){a=0xfc;return;}
if(asc=='1'){a=0x60;return;}
if(asc=='2'){a=0xda;return;}
if(asc=='3'){a=0xf2;return;}
if(asc=='4'){a=0x66;return;}
if(asc=='5'){a=0xb6;return;}
if(asc=='6'){a=0xbe;return;}
if(asc=='7'){a=0xe0;return;}
if(asc=='8'){a=0xfe;return;}
if(asc=='9'){a=0xf6;return;}
if(asc=='A'||asc=='a'){a=0xee;return;}
if(asc=='B'||asc=='b'){a=0x3e;return;}
if(asc=='C'||asc=='c'){a=0x9C;return;}
if(asc=='D'||asc=='d'){a=0x7a;return;}
if(asc=='E'||asc=='e'){a=0x9e;return;}
if(asc=='F'||asc=='f'){a=0x8e;return;}
if(asc=='G'||asc=='g'){a=0xf6;return;}
if(asc=='H'||asc=='h'){a=0x6e;return;}
if(asc=='I'||asc=='i'){a=0x60;return;}
if(asc=='J'||asc=='j'){a=0x70;return;}
if(asc=='K'||asc=='k'){a=0xAE;return;}
if(asc=='L'||asc=='l'){a=0x1c;return;}
//if(asc=='M'||asc=='m'){a=0x60;return;}
if(asc=='N'||asc=='n'){a=0x2a;return;}
if(asc=='O'||asc=='o'){a=0x3a;return;}
if(asc=='P'||asc=='p'){a=0xce;return;}
if(asc=='Q'||asc=='q'){a=0xe6;return;}
if(asc=='R'||asc=='r'){a=0x0a;return;}
if(asc=='S'||asc=='s'){a=0xb6;return;}
if(asc=='T'||asc=='t'){a=0xe0;return;}
if(asc=='U'||asc=='u'){a=0x7C;return;}
//if(asc=='V'||asc=='v'){a=0x60;return;}
//if(asc=='W'||asc=='w'){a=0x60;return;}
//if(asc=='X'||asc=='x'){a=0x60;return;}
if(asc=='Y'||asc=='y'){a=0x76;return;}
//if(asc=='Z'||asc=='z'){a=0x60;return;}
}
void address(unsigned char ad)
{
   	unsigned char i;
	LCS=0;
	for(i=0;i<8;i++)  //data
	{
		DATA =ad&0x01;
		CLK = 0;
		CLK = 1;
		ad=ad>>1;
	}
}
void write(unsigned char id)
{
    unsigned char i;
	convert(id);
	for(i=0;i<8;i++)  //data
	{
		DATA =a&0x01;
		CLK = 0;
		CLK = 1;
		a=a>>1;
	}
	LCS=1;
}
void main()
{
EA = 0; /* disable interrupts */
TR0 = 0; /* stop timer 0 */
TMOD &= ~0x0F; /* clear timer 0 mode bits */
TMOD |= 0x01; /* put timer 0 into 16-bit no prescale */
TL0 = (TIMER0_COUNT & 0x00FF);
TH0 = (TIMER0_COUNT >> 8);
PT0 = 0; /* set low priority for timer 0 */
ET0 = 1; /* enable timer 0 interrupt */
TR0 = 1; /* start timer 0 */
EA = 1; /* enable interrupts */	 

 while(1)
 {
   printf("12345");
 }

}

char putchar(char charIN)
{
unsigned char iter = 0;
if (charIN != '\n') // not a new line
{
if ((charIN & 0x80) == 0) { // translation necesssary
charIN = translation_table [charIN]; } // quick lookup

EA = 0; // prevent partial display
for (iter = 0; iter < 5; iter++) { // shift the digits left
LCD_digits[iter] = LCD_digits[iter+1]; }
LCD_digits[5] = charIN; // new digit is rightmost
EA = 1; // enable interrupts again
}

else // input is a newline
{
EA = 0; // disable interrupts
for (iter = 0; iter < 8; iter++) 
{
LCD_digits[iter] = 0x00;
} // clear all digits
EA = 1; // enable interrupts
}

if (charIN == 0xFF) 
{ // couldn't interpret OR space
charIN = ' '; 
} // return space
return charIN; // just like putchar
}