Displaying an Image on Graphical LCD using 8051 Microcontroller

In our daily life, we see many types of devices for displaying Text, Images and Graphics. LCDs are one of the most popular Display Device in Electronics and used in mostly all the projects which display some kind of information. There are many types of LCDs used in Electronic Projects. We have already used 16X2 LCD in many of our projects and also used TFT LCD with Arduino. You can find all our 16X2 LCD related project by following this link, including interfacing with 8051, AVR, Arduino and many more.

In this tutorial we are going to do Graphic LCD interfacing with 8051 microcontroller. In this project, we will show how to Display an Image on Graphical LCD (GLCD).

 

Components Required:

• Graphical LCD
• AT89c52 8051 Microcontroller
• 7805 voltage regulator
• 1000uf capacitor
• 10 uF capacitor
• 10K resistor
• 10K POT
• Crystal Oscillator 12 MH
• Connecting wire
• Bread Board
• Burg strips male
• Power supply                    
• LED
• 220 Ohm resistor
• 1K resistor

 

Graphical LCD:

 

A simple 16x2 LCD has 16 pins but Graphical LCD has 20 pin. Pin description is given below as per its datasheet:

Pin No.	Pin Name	Description	Function
1	VSS	Ground	0 Volt
2	VDD	Power Supply	5 Volt
3	V0	LCD Contrast adjustment
4	RS	Command/data Register selection	RS=0: Command Selection and RS=1: Data Selection
5	R/W	Read/Write Register	R/W=0: Write Selection and R/W=1: Read Selection
6	E	Enable Signal
7	DB0	Data input/output pin (DB0-DB7)	8 Bit (DB0-DB7)
8	DB1
9	DB2
10	DB3
11	DB4
12	DB5
13	DB6
14	DB7
15	CS1	Chip Select	CS1 = 1, Chip Select Signal for IC1
16	CS2	Chip Select	CS2 = 1, Chip Select Signal for IC2
17	RST	Reset	Reset GLCD
18	VEE	Negative Voltage for LCD Driver
19	A	Back light LED	5 Volt
20	K	Back light LED	Ground

Showing an Image on Graphical LCD using 8051:

To show an Image on Graphical LCD, first we need to convert that image into Assembly Code, so that 8051 Microcontroller can understand and read it. So we need to follow the below Steps for Converting Image into HEX code:

 

Step 1: First we need to download a application which convert Image (BMP format) into Assembly Code. So download the BMP2ASM Image Conversion Application from this link, just Right Click on the link and then click Save link as…

Step 2: Then, select the image which you want to display on the Graphical LCD and convert it into BMP, (if it is not in BMP format already) using any application like MS Paint, Photoshop etc. Or you can find many online website for Image format conversion. We have below BMP image, with size 128x64:

 

Step 3: Now extract the BMP2ASM.zip file, which we have downloaded in Step 1 and open Bmp2asm.exe within it, and select the BMP image.

 

 

Step 4: Now press “Convert” in BMP2ASM application window.

 

Step 5: Then Copy the generated code and paste in the program of 8051 in Keil uVision. Do some changes and compile the code.

Now your code is ready to upload in 8051 Microcontroller. 

 

Circuit Explanation:

Circuit connections, for Interfacing Graphical LCD to 8051 Microcontroller, is easy and almost same like connecting 16x2 LCD to 8051. But 16x2 LCD has 16 pins and GLCD has 20 pin.

A 10K pot is used for set contrast for GLCD. Control Pins of GLCD RS, R/W and E are directly connected to 89C52 pin number P1.0, P1.1 and P1.2. Chip select pins CS1 and CS2 of LCD are connected to pin P1.3 and P1.4 respectively. Data pins DB0-DB7 are directly connected at PORT P2. A 7805 Voltage regulator is used for regular 5 volt supply. In demonstration Video, I have used Arduino power supply.

 

Programming Explanation:

First of all, we include required header files in the program and define bits for Control and Data Pins of GLCD.

#include<reg51.h>
#include<intrins.h>
#define lcdport P2

sbit rs=P1^0;
sbit rw=P1^1;
sbit en=P1^2;
sbit cs1=P1^3;
sbit cs2=P1^4;

 

After it, we have created a delay function.

void delay(int itime)
{
  int i,j;
  for(i=0;i<itime;i++)
  for(j=0;j<125;j++);
}

 

Function void lcd_disp_on() is used for Turning On the display.

Function void setCursorY(int y) is created for setting the column in GLCD and Function void setCursorX(int x) is created for setting the page on the GLCD. Complete Code file is given in below Code Section.

 

After setting Column and Page, we have written a function for sending command and data to GLCD.

void lcdprint(char dat,int size)
{
    unsigned int i;
    for(i=0;i<size;i++)
    {
        if(c<64)
        {
            lcdport=dat;
            cs1=1;
    .... .....
    .... .....

 

In void main() function, we have cleared GLCD and then set Column and Page. After it, send data to LCD by using void lcdprint(char dat,int size) function.

void main()
{ 
    int x,y;
    P3=0xff;
    while(1)
    {
           lcdclear();
       for(y=0;y<8;y++)
       {
        for(x=0;x<128;x++)
        {
          lcd_disp_on(); 
          setCursorX(y);
          setCursorY(x);
          lcdprint(image[y][x],x);
        }
       }
    ..... ......
    ..... .......

 

Flow of Code:

1. First when we Power up the system, program clears the GLCD and Turns On the display.
2. Then set cursor to Column, from where we want to write the Data.
3. Then set cursor to Page, from where we want to write the Data.
4. Now program sends Data to the selected location one by one till 128X8 Times. Because a GLCD has 8 pages and 128 Columns.