Introduction
Introduction to 8051
A BRIEF INTRODUCTION TO 8051 MICROCONTROLLER
The pin diagram of the 8051 shows all of the input/output pins unique to microcontrollers:
The following are some of the capabilities of 8051 microcontroller.
§ Internal ROM and RAM
§ I/O ports with programmable pins
§ Timers and counters
§ Serial data communication
The 8051 architecture consists of these specific features:
§ 16 bit PC &data pointer (DPTR)
§ 8 bit program status word (PSW)
§ 8 bit stack pointer (SP)
§ Internal ROM 4k
§ Internal RAM of 128 bytes.
§ 4 register banks, each containing 8 registers
§ 80 bits of general purpose data memory
§ 32 input/output pins arranged as four 8 bit ports P0-P3
§ Two 16 bit timer/counters: T0-T1
§ Two external and three internal interrupt sources
§ Oscillator and clock circuits
Pin Diagram of 8051
Introduction to 16 X2 LCD
• 5 x 8 dots with cursor
• Built-in controller (KS 066 or Equivalent)
• + 5V power supply (Also available for + 3V)
• 1/16 duty cycle
• B/L to be driven by pin 1, pin 2 or pin 15, pin 16 or A.K (LED)
• N.V. optional for + 3V power supply
Pin Description:
Interfacing LCD with 8051
Matrix Keyboard introduction
Scanning a Matrix Keypad
Tools Used
Software tools
Hardware tools
Components
PCB Layout for moving message display.
Program for LCD based Moving Message Display
#include <reg51.h>
#include <LCD.H>
#include <string.h>
sbit led=P2^0; //Output
sbit r4 =P1^0; //Input
sbit r3 =P1^1; //Input
sbit r2 =P1^2; //Input
sbit r1 =P1^3; //Input
sbit c1 =P1^4; //Output
sbit c2 =P1^5; //Output
sbit c3 =P1^6; //Output
sbit c4 =P1^7; //Output
char na[30];
void wait()
{ while(c1==0||c2==0||c3==0 || c4==0)
{ }
return;
}
unsigned char fun(unsigned char *p)
{ unsigned char i;
while(1)
{ for(i=0;p[i]!=0;i++)
{
// if((i+1)%14==0) {startit();}
startit();
LCDData(p[i]);
led=0;
msdelay(300);
led=1;
if (!(c1==0 || c2==0 || c3==0 || c4==0)) return p[i];
}
}
}
unsigned char readchar()
{ led=0;//led on
while(1)
{
r1=0;r2=1;r3=1;r4=1;
if(c1==0)
{ return fun("1+-/{}[]()!@#$%^&,.<>;':\"|\\"); }
if(c2==0)
{return fun("2abcABC"); }
if(c3==0)
{return fun("3defDEF"); }
if(c4==0)
{ wait(); msdelay(200);led=1;return 200; }
r1=1;r2=0;r3=1;r4=1;
if(c1==0)
{return fun("4ghiGHI"); }
if(c2==0)
{return fun("5jklJKL"); }
if(c3==0)
{return fun("6mnoMNO"); }
if(c4==0)
{wait(); msdelay(200);led=1;return 201; }
r1=1;r2=1;r3=0;r4=1;
if(c1==0)
{return fun("7pqrsPQRS"); }
if(c2==0)
{return fun("8tuvTUV"); }
if(c3==0)
{return fun("9wxyzWXYZ"); }
if(c4==0)
{wait(); msdelay(200);led=1;return 202; }
r1=1;r2=1;r3=1;r4=0;
if(c1==0)
{return fun("*"); }
if(c2==0)
{return fun("0 "); }
if(c3==0)
{return fun("#."); }
if(c4==0)
{wait(); msdelay(200);led=1;return 203; }
}
return 0;
}
void main()
{
unsigned char ch,i,j;
P0=0; //output
P1=255;//0B11111111; //mix
startit();
outtext("Moving Message Display");
msdelay(200);
startit();
outtext("Enter message : ");
msdelay(200);
startit();
i=0;
while(1)
{
ch=readchar();
if(ch==0) continue;
if(ch==200) break;
na[i]=ch;
i++;
}
while(1)
{
i=0;
while(1)
{
startit();
j=i;
while(1)
{
if(na[j]==0) break;
LCDData(na[j]);
j++;
}
i++;
msdelay(100);
if(na[i]==0) break;
}
}
}
LCD.H
#include <reg51.h>
sbit rs = P2^5; //Output
sbit rw = P2^6; //Output
sbit en = P2^7; //output
void msdelay(int n)
{ int i,j;
for(i=1;i<=n;i++){for(j=1;j<=1200;j++){}}
return;
}
void LCDCmd(unsigned char ch)
{ rs = 0; rw = 0; en = 1;
P0=ch; msdelay(1); en = 0;
return;
}
void LCDData(unsigned char ch)
{ rs = 1; rw = 0; en = 1;
P0=ch; msdelay(1); en = 0;
return;
}
void startit()
{ LCDCmd(0x38); LCDCmd(0x0e); LCDCmd(0x01); return;}
void outtext(unsigned char *s)
{ while(*s!=0)
{ LCDData(*s);s++; }
return;
}
Future Enhancements
Can be installed with extra ram / flash memory to hold predefined messages and to store custom messages.
Display size can be increased by using LED Matrix Display
Applications
Can be used to display advertisements .
Can be used as a small notice board.
PROGRAM
LCD.c
#include <reg51.h>
#include <LCD.H>
#include <string.h>
#define on 0
#define of 1
sbit led=P2^0; //Output
sbit r4 =P1^0; //Input
sbit r3 =P1^1; //Input
sbit r2 =P1^2; //Input
sbit r1 =P1^3; //Input
sbit c1 =P1^4; //Output
sbit c2 =P1^5; //Output
sbit c3 =P1^6; //Output
sbit c4 =P1^7; //Output
char na[50]=" Hello World How are you. ";
unsigned char cou;
void wait()
{ while(c1==0||c2==0||c3==0 || c4==0)
{ }
return;
}
void back()
{ LCDCmd(0x10); }
unsigned char fun(unsigned char *p)
{ unsigned char i,j;
char st;
LCDData(' ');
while(1)
{ for(i=0;p[i]!=0;i++)
{ back();
LCDData(p[i]);
led=0;
wait();
msdelay(50);
led=1;
st=0;
for(j=0;j<=200;j++)
{ msdelay(1);
if(c1==0 || c2==0 || c3==0 || c4==0)
{
st=1;
break;
}
}
if(st==0)
{led=1;
return p[i];
}
}
}
}
unsigned char readchar()
{ led=0;//led on
cou=0;
while(1)
{ r1=0;r2=1;r3=1;r4=1;
if(c1==0) { return fun("1+-/{}[]()!@#$%^&,.<>;':\"|\\"); }
if(c2==0) {return fun("2ABCabc"); }
if(c3==0) {return fun("3DEFdef"); }
if(c4==0) { wait(); msdelay(200);led=1;return 200; }
r1=1;r2=0;r3=1;r4=1;
if(c1==0) {return fun("4GHIghi"); }
if(c2==0) {return fun("5JKLjkl"); }
if(c3==0) {return fun("6MNOmno"); }
if(c4==0) {wait(); msdelay(200);led=1;return 201; }
r1=1;r2=1;r3=0;r4=1;
if(c1==0) {return fun("7PQRSpqrs"); }
if(c2==0) {return fun("8TUVtuv"); }
if(c3==0) {return fun("9WXYZwxyz"); }
if(c4==0) {wait(); msdelay(200);led=1;return 202; }
r1=1;r2=1;r3=1;r4=0;
if(c1==0) {return fun("*"); }
if(c2==0) {return fun("0 "); }
if(c3==0) {return fun("#."); }
if(c4==0) {wait(); msdelay(200);led=1;return 203; }
}
return 0;
}
void main()
{ unsigned char ch,i,j,z;
led=0;//led on
P0=0; //output
P1=255;//0B11111111; //mix
startit();
LCDCmd(0xe);
outtext("Mov.Msg.Display");
msdelay(200);
startit();
outtext("Enter message : ");
msdelay(200);
startit();
i=0;
led=1; //led off
for(i=0;i<=49;i++)
{ na[i]=0;}
for(i=0;i<=15;i++)
{ na[i]=32;}
z=0;
while(1)
{
ch=readchar();
if(ch==0) continue;
if(ch==200) break;
if(ch==201) //Back Space Pressed
{ back(); LCDData(' ');back();i--;na[i]=0;z--;continue;}
na[i]=ch;
z++;
i++;
if(z>=15)
{ startit(); outtext(&na[i-10]); }
}
na[i]=32;
i++;
na[i]=0;
LCDCmd(0x0C);
while(1)
{
i=0;
while(1)
{
//startit();
LCDCmd(0x01);
LCDCmd(0x80);
j=i;
cou=0;
while(1)
{
if(na[j]==0 || cou==16) break;
LCDData(na[j]);
j++;
cou++;
}
i++;
msdelay(200);
if(na[i]==0) break;
}
}
}
LCD.H
#include <reg51.h>
sbit rs = P2^5; //Output
sbit rw = P2^6; //Output
sbit en = P2^7; //output
void msdelay(int n)
{ int i,j;
for(i=1;i<=n;i++){for(j=1;j<=1200;j++){}}
return;
}
void LCDCmd(unsigned char ch)
{ rs = 0; rw = 0; en = 1;
P0=ch;
msdelay(1);
en = 0;
return;
}
void LCDData(unsigned char ch)
{ rs = 1; rw = 0; en = 1;
P0=ch; msdelay(1);
en = 0;
return;
}
void startit()
{
LCDCmd(0x38); LCDCmd(0x0e); LCDCmd(0x01);
return;
}
void outtext(unsigned char *s)
{ while(*s!=0)
{ LCDData(*s);s++; }
return;
}
In the current age where what is show is sold every one need to cater the power of technology to enhance his/her business or to present the products with which he/she deals. Cloth banners become an old age concept. LED Matrix displays and LCD Based displays are growing in the market. In spite of these LED/LCD displays can be used as message board to display current messages / news.
The current moving message display is developed using the discrete components like 16 X 2 LCD. P89V51RD2 Microcontroller which is 8051 based microcontroller with 32 i/o pins and capable enough to old 4kb of program in its flash. It is fed with 12 MHz frequency with appropriate crystal. Further a 4X4 matrix keyboard is provided with it to feed the required message at the startup. Almost all the keys in the keyboard are multifunctional. The characters which can be part of the message include alphabets (a-z) & (A-Z) , Numerials (0-9) and special characters like +-/{}[]()!@#$%^&,.<>;':"|. The whole unit need 5V DC Supply to run it. Which is provided from a 5V DC regulated supply which used 7805 as a key component to regulate the voltage.
Introduction to 8051
A BRIEF INTRODUCTION TO 8051 MICROCONTROLLER
When we have to learn about a new computer we have to familiarize about the machine capability we are using, and we can do it by studying the internal hardware design (devices architecture), and also to know about the size, number and the size of the registers.
A microcontroller is a single chip that contains the processor (the CPU), non-volatile memory for the program (ROM or flash), volatile memory for input and output (RAM), a clock and an I/O control unit. Also called a "computer on a chip," billions of microcontroller units (MCUs) are embedded each year in a myriad of products from toys to appliances to automobiles. For example, a single vehicle can use 70 or more microcontrollers. The following picture describes a general block diagram of microcontroller.89s52: The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel's AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications. The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM con-tents but freezes the oscillator, disabling all other chip functions until the next interrupt.The hardware is driven by a set of program instructions, or software. Once familiar withhardware and software, the user can then apply the microcontroller to the problems easily.
The following are some of the capabilities of 8051 microcontroller.
§ Internal ROM and RAM
§ I/O ports with programmable pins
§ Timers and counters
§ Serial data communication
The 8051 architecture consists of these specific features:
§ 16 bit PC &data pointer (DPTR)
§ 8 bit program status word (PSW)
§ 8 bit stack pointer (SP)
§ Internal ROM 4k
§ Internal RAM of 128 bytes.
§ 4 register banks, each containing 8 registers
§ 80 bits of general purpose data memory
§ 32 input/output pins arranged as four 8 bit ports P0-P3
§ Two 16 bit timer/counters: T0-T1
§ Two external and three internal interrupt sources
§ Oscillator and clock circuits
Pin Diagram of 8051
Introduction to 16 X2 LCD
LCD (Liquid Crystal Display) screen is an electronic display module and find a wide range of applications. A 16x2 LCDdisplay is very basic module and is very commonly used in various devices and circuits. These modules are preferred over seven segments and other multi segment LEDs. The reasons being: LCDs are economical; easily programmable; have no limitation of displaying special & even custom characters (unlike in seven segments), animations and so on.
A 16x2 LCD means it can display 16 characters per line and there are 2 such lines. In this LCD each character is displayed in 5x7 pixel matrix. This LCD has two registers, namely, Command and Data.The command register stores the command instructions given to the LCD. A command is an instruction given to LCD to do a predefined task like initializing it, clearing its screen, setting the cursor position, controlling display etc. The data register stores the data to be displayed on the LCD. The data is the ASCII value of the character to be displayed on the LCD.
Features: • 5 x 8 dots with cursor
• Built-in controller (KS 066 or Equivalent)
• + 5V power supply (Also available for + 3V)
• 1/16 duty cycle
• B/L to be driven by pin 1, pin 2 or pin 15, pin 16 or A.K (LED)
• N.V. optional for + 3V power supply
Pin Description:
PIN NUMBER
|
SYMBOL
|
FUNCTION
|
1
|
VSS
|
GND
|
2
|
VDD
|
+ 3V or + 5V
|
3
|
Vo
|
Contrast Adjustment
|
4
|
RS
|
H/L Register Select Signal
|
5
|
R/W
|
H/L Read/Write Signal
|
6
|
E
|
H?L Enable Signal
|
7
|
DB0
|
H/L Data Bus Line
|
8
|
DB1
|
H/L Data Bus Line
|
9
|
DB2
|
H/L Data Bus Line
|
10
|
DB3
|
H/L Data Bus Line
|
11
|
DB4
|
H/L Data Bus Line
|
12
|
DB5
|
H/L Data Bus Line
|
13
|
DB6
|
H/L Data Bus Line
|
14
|
DB7
|
H/L Data Bus Line
|
15
|
A/VEE
|
+ 4.2V for LED/Negative Voltage Output
|
16
|
K
|
Power Supply for B/L (OV)
|
Interfacing LCD with 8051
Matrix Keyboard introduction
Keypads are a part of HMI or Human Machine Interface and play really important role in a small embedded system where human interaction or human input is needed. Martix keypads are well known for their simple architecture and ease of interfacing with any microcontroller. In this part of tutorial we will learn how to interface a 4x4 matrix keypad with AVR and 8051 microcontroller. Also we will see how to program then in Assembly and C.
►Constructing a Matrix Keypad
Constuction of a keypad is really simple. As per the outline shown in the figure below we have four rows and four columns. In between each overlapping row and column line there is a key.
Scanning a Matrix Keypad
There are many methods depending on how you connect your keypad with your controller, but the basic logic is same. We make the coloums as i/p and we drive the rows making them o/p, this whole procedure of reading the keyboard is called scanning.
In order to detect which key is pressed from the matrix, we make row lines low one by one and read the coloums. Lets say we first make Row1 low, then read the columns. If any of the key in row1 is pressed will make the corrosponding column as low i.e if second key is pressed in Row1, then column2 will give low. So we come to know that key 2 of Row1 is pressed. This is how scanning is done.
So to scan the keypad completely, we need to make rows low one by one and read the columns. If any of the button is pressed in a row, it will take the corrosponding column to a low state which tells us that a key is pressed in that row. If button 1 of a row is pressed then Column 1 will become low, if button 2 then column2 and so on...
Tools Used
Software tools
- Keil C compiler
- Flash Magic for burner
- PCB Designing Software like PCB Express
Hardware tools
- Soldering iron
- Soldering flux
- Solder
- Multi-meter
- Nipper
- Wires
- 8051 Burner Circuit
- USB to RS232 Converter
- Laptop installed with required software’s
- Laser Printer for PCB Printing
Components
- Copper Clad
- Magazine Paper
- HCL (Hydrocloric Acid)
- Hydrogen Liquid
- P89v51RD2 (8051 microcontroller)
- LCD 16X2
- 12MHz Crystal
- 33pf Capacitor (2 Nos)
- 10uf Capacitor
- 10k Resistance
- 17 Nos Reset Switch
- Burg Connector 16 Pin (Male and Female Pair)
- 10 k Preset for Contrast Setting of LCD
- RED LED
- 6-0-6 200v Transformer
- IN4007 Diode (4 Nos)
- 1000uf Capacitor 25 V
- 7805 Voltage Regulator
- General PCB for Power Supply
- Green LED for power supply
- 220Ohm Resistance (2 Nos)
- Power cord for Power Supply
- 2 pin connector with wire for power supply to main PCB
PCB Layout for moving message display.
Program for LCD based Moving Message Display
#include <reg51.h>
#include <LCD.H>
#include <string.h>
sbit led=P2^0; //Output
sbit r4 =P1^0; //Input
sbit r3 =P1^1; //Input
sbit r2 =P1^2; //Input
sbit r1 =P1^3; //Input
sbit c1 =P1^4; //Output
sbit c2 =P1^5; //Output
sbit c3 =P1^6; //Output
sbit c4 =P1^7; //Output
char na[30];
void wait()
{ while(c1==0||c2==0||c3==0 || c4==0)
{ }
return;
}
unsigned char fun(unsigned char *p)
{ unsigned char i;
while(1)
{ for(i=0;p[i]!=0;i++)
{
// if((i+1)%14==0) {startit();}
startit();
LCDData(p[i]);
led=0;
msdelay(300);
led=1;
if (!(c1==0 || c2==0 || c3==0 || c4==0)) return p[i];
}
}
}
unsigned char readchar()
{ led=0;//led on
while(1)
{
r1=0;r2=1;r3=1;r4=1;
if(c1==0)
{ return fun("1+-/{}[]()!@#$%^&,.<>;':\"|\\"); }
if(c2==0)
{return fun("2abcABC"); }
if(c3==0)
{return fun("3defDEF"); }
if(c4==0)
{ wait(); msdelay(200);led=1;return 200; }
r1=1;r2=0;r3=1;r4=1;
if(c1==0)
{return fun("4ghiGHI"); }
if(c2==0)
{return fun("5jklJKL"); }
if(c3==0)
{return fun("6mnoMNO"); }
if(c4==0)
{wait(); msdelay(200);led=1;return 201; }
r1=1;r2=1;r3=0;r4=1;
if(c1==0)
{return fun("7pqrsPQRS"); }
if(c2==0)
{return fun("8tuvTUV"); }
if(c3==0)
{return fun("9wxyzWXYZ"); }
if(c4==0)
{wait(); msdelay(200);led=1;return 202; }
r1=1;r2=1;r3=1;r4=0;
if(c1==0)
{return fun("*"); }
if(c2==0)
{return fun("0 "); }
if(c3==0)
{return fun("#."); }
if(c4==0)
{wait(); msdelay(200);led=1;return 203; }
}
return 0;
}
void main()
{
unsigned char ch,i,j;
P0=0; //output
P1=255;//0B11111111; //mix
startit();
outtext("Moving Message Display");
msdelay(200);
startit();
outtext("Enter message : ");
msdelay(200);
startit();
i=0;
while(1)
{
ch=readchar();
if(ch==0) continue;
if(ch==200) break;
na[i]=ch;
i++;
}
while(1)
{
i=0;
while(1)
{
startit();
j=i;
while(1)
{
if(na[j]==0) break;
LCDData(na[j]);
j++;
}
i++;
msdelay(100);
if(na[i]==0) break;
}
}
}
LCD.H
#include <reg51.h>
sbit rs = P2^5; //Output
sbit rw = P2^6; //Output
sbit en = P2^7; //output
void msdelay(int n)
{ int i,j;
for(i=1;i<=n;i++){for(j=1;j<=1200;j++){}}
return;
}
void LCDCmd(unsigned char ch)
{ rs = 0; rw = 0; en = 1;
P0=ch; msdelay(1); en = 0;
return;
}
void LCDData(unsigned char ch)
{ rs = 1; rw = 0; en = 1;
P0=ch; msdelay(1); en = 0;
return;
}
void startit()
{ LCDCmd(0x38); LCDCmd(0x0e); LCDCmd(0x01); return;}
void outtext(unsigned char *s)
{ while(*s!=0)
{ LCDData(*s);s++; }
return;
}
Future Enhancements
Can be installed with extra ram / flash memory to hold predefined messages and to store custom messages.
Display size can be increased by using LED Matrix Display
Applications
Can be used to display advertisements .
Can be used as a small notice board.
PROGRAM
LCD.c
#include <reg51.h>
#include <LCD.H>
#include <string.h>
#define on 0
#define of 1
sbit led=P2^0; //Output
sbit r4 =P1^0; //Input
sbit r3 =P1^1; //Input
sbit r2 =P1^2; //Input
sbit r1 =P1^3; //Input
sbit c1 =P1^4; //Output
sbit c2 =P1^5; //Output
sbit c3 =P1^6; //Output
sbit c4 =P1^7; //Output
char na[50]=" Hello World How are you. ";
unsigned char cou;
void wait()
{ while(c1==0||c2==0||c3==0 || c4==0)
{ }
return;
}
void back()
{ LCDCmd(0x10); }
unsigned char fun(unsigned char *p)
{ unsigned char i,j;
char st;
LCDData(' ');
while(1)
{ for(i=0;p[i]!=0;i++)
{ back();
LCDData(p[i]);
led=0;
wait();
msdelay(50);
led=1;
st=0;
for(j=0;j<=200;j++)
{ msdelay(1);
if(c1==0 || c2==0 || c3==0 || c4==0)
{
st=1;
break;
}
}
if(st==0)
{led=1;
return p[i];
}
}
}
}
unsigned char readchar()
{ led=0;//led on
cou=0;
while(1)
{ r1=0;r2=1;r3=1;r4=1;
if(c1==0) { return fun("1+-/{}[]()!@#$%^&,.<>;':\"|\\"); }
if(c2==0) {return fun("2ABCabc"); }
if(c3==0) {return fun("3DEFdef"); }
if(c4==0) { wait(); msdelay(200);led=1;return 200; }
r1=1;r2=0;r3=1;r4=1;
if(c1==0) {return fun("4GHIghi"); }
if(c2==0) {return fun("5JKLjkl"); }
if(c3==0) {return fun("6MNOmno"); }
if(c4==0) {wait(); msdelay(200);led=1;return 201; }
r1=1;r2=1;r3=0;r4=1;
if(c1==0) {return fun("7PQRSpqrs"); }
if(c2==0) {return fun("8TUVtuv"); }
if(c3==0) {return fun("9WXYZwxyz"); }
if(c4==0) {wait(); msdelay(200);led=1;return 202; }
r1=1;r2=1;r3=1;r4=0;
if(c1==0) {return fun("*"); }
if(c2==0) {return fun("0 "); }
if(c3==0) {return fun("#."); }
if(c4==0) {wait(); msdelay(200);led=1;return 203; }
}
return 0;
}
void main()
{ unsigned char ch,i,j,z;
led=0;//led on
P0=0; //output
P1=255;//0B11111111; //mix
startit();
LCDCmd(0xe);
outtext("Mov.Msg.Display");
msdelay(200);
startit();
outtext("Enter message : ");
msdelay(200);
startit();
i=0;
led=1; //led off
for(i=0;i<=49;i++)
{ na[i]=0;}
for(i=0;i<=15;i++)
{ na[i]=32;}
z=0;
while(1)
{
ch=readchar();
if(ch==0) continue;
if(ch==200) break;
if(ch==201) //Back Space Pressed
{ back(); LCDData(' ');back();i--;na[i]=0;z--;continue;}
na[i]=ch;
z++;
i++;
if(z>=15)
{ startit(); outtext(&na[i-10]); }
}
na[i]=32;
i++;
na[i]=0;
LCDCmd(0x0C);
while(1)
{
i=0;
while(1)
{
//startit();
LCDCmd(0x01);
LCDCmd(0x80);
j=i;
cou=0;
while(1)
{
if(na[j]==0 || cou==16) break;
LCDData(na[j]);
j++;
cou++;
}
i++;
msdelay(200);
if(na[i]==0) break;
}
}
}
LCD.H
#include <reg51.h>
sbit rs = P2^5; //Output
sbit rw = P2^6; //Output
sbit en = P2^7; //output
void msdelay(int n)
{ int i,j;
for(i=1;i<=n;i++){for(j=1;j<=1200;j++){}}
return;
}
void LCDCmd(unsigned char ch)
{ rs = 0; rw = 0; en = 1;
P0=ch;
msdelay(1);
en = 0;
return;
}
void LCDData(unsigned char ch)
{ rs = 1; rw = 0; en = 1;
P0=ch; msdelay(1);
en = 0;
return;
}
void startit()
{
LCDCmd(0x38); LCDCmd(0x0e); LCDCmd(0x01);
return;
}
void outtext(unsigned char *s)
{ while(*s!=0)
{ LCDData(*s);s++; }
return;
}
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