15EE51 - Microcontrollers Laboratory

MICROCONTROLLERS LABORATORY (15EE51) REPORT
JABEZ WINSTON C 15MU01
Microcontroller Laboratory report submitted in partial fulfilment of the requirements for the degree
of
MASTER OF ENGINEERING
Branch: ELECTRICAL AND ELECTRONICS ENGINEERING
EMBEDDED AND REAL TIME SYSTEMS
Of Anna University, Chennai.
December 2015
DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING
PSG COLLEGE OF TECHNOLOGY
(Autonomous Institution)
COIMBATORE – 641 004

TABLE OF CONTENTS
Ex.No Date Title of the Experiment
Page
No.
Signature of Staff
1 7-9-2015
INTRODUCTION TO KEIL µVISION IDE 1
Debug Windows and Dialogs 1
Working with Keil µVision IDE 3
Sample program for blinking LEDs 11
2 10-10-2015
ASSEMBLY LANGAGE PROGRAMMING IN 8051 14
Timers/Counters 14
Serial Communication 17
Interrupts 19
3 12-11-2015
C LANGUAGE PROGRAMMING IN 8051 22
Timers/Counters 22
Serial Communication 26
Interrupts 28
4 16-11-2015
INTERFACED HARDWARE WITH 8051 30
LED interfacing with Zkit-51 30
Buzzer interfacing with Zkit-51 31
LCD interfacing with Zkit-51 32
Matrix keypad interfacing with Zkit-51 35

TABLE OF FIGURES
Fig.No. Title of the Figure Page No.
1.1 Keil IDE showing the various Windows available 2
1.2 Creation of new project 3
1.3 ‘Create New Project’ Window 3
1.4 ‘Select Device for Target’ Window 4
1.5 Drop down Menu in Project Window 4
1.6 ‘Add New Item ‘ Dialog Box 5
1.7 Keil IDE with sample program 5
1.8 ‘View’ Drop down menu in Keil IDE 6
1.9 Logic Analyzer Setup 6
1.10 Logic Analyzer Window 7
1.11 Setup Performance Analyzer 7
1.12 Performance Analyzer Window 7
1.13 Register Window 8
1.14 Memory Window showing Code Memory 8
1.15 Memory Window showing Data Memory 8
1.16 Disassembly Window 9
1.17 Serial Window 9
1.18 Program having breakpoints at Line 4,11,13 10
1.19 ‘Flash’ Drop Down Menu in Keil IDE 10
1.20 ‘Options for Target’ Window 10
1.21 HEX file in Objects Folder 11
1.22 Contents of HEX file 11
1.23 LED Window 12
1.24 LED Setup 13
1.25 LED Window showing LEDs 13
2.1 Waveform at P1.5 14
2.2 Timer 1 registers 15
2.4 Counter output 16
2.5 Serial Communication 18

2.6 Windows showing Interrupts and Serial Communication 20
3.2 Timer registers 23
3.3 Counter output 25
3.4 Serial Communication 27
3.5 External ,Timer and Serial Communication Interrupt 29
4.1 RED LED glowing when KEY1 is pressed 31
4.2 GREEN LED glowing when KEY2 is pressed 31
4.3 Two strings printed on LCD 35
4.4 Matrix keypad and 16 x 2 LCD display 38

15EE51 – Microcontrollers Laboratory Page 1
1.INTRODUCTION TO KEIL µVISION IDE
Keil µVision IDE is a window-based software development platform for 8051 and ARM
microcontrollers that combines a robust and modern editor with a project manager and make facility
tool. It integrates all the tools needed to develop embedded applications including a C/C++ compiler,
macro assembler, linker/locator, and a HEX file generator.
µVision GUI
The µVision GUI provides menus for selecting commands and toolbars with command buttons. The
Status Bar, at the bottom of the window, displays information and messages about the current
µVision command. Windows can be relocated and docked to another physical screen. The window
layout is saved for each project automatically and restored the next time the project is used. You can
restore the default layout using the menu Window – Reset View to Defaults.
µVision has two operating modes, the Build Mode for creating applications and the Debug Mode for
analyzing applications, which offers additional Windows and Dialogs.
Debug Windows and Dialogs
µVision provides many debugging windows and dialogs. Some of them are
 Breakpoints- Define stop conditions for program execution.
 Code Coverage- Examine statistics about code execution, including branch testing.
 Command Window- Enter and view executed commands.
 Disassembly Window- Test programs at the level of assembly instructions.
 Logic Analyzer - Investigate value changes of peripherals, registers, and variables on a time
graph.
 Memory Map- Evaluate memory areas and their access rights.
 Memory Window - Analyze and modify memory content.
 Performance Analyzer - Evaluate time and call statistics on module or function level.
 Registers Window- view and modify register content.
 Serial Window is a communication interface between the application and the PC.
 Status Bar - View debugging status information.
 Symbols Window- Find debug symbol information used in program.
 System Viewer Find peripheral register information and change property values at runtime.
 Toolbox Use and define configurable buttons for executing debugging commands
interactively.
Ex. No. 1
07-09-2015

Introduction to Keil µVision IDE
Fig1.1:KeilIDEshowingthevariousWindowsavailable

Working with Keil µVision IDE
Getting started…
1.OpenKeil µVision ,Click Project New µVision Project.
2.Type a name and save the project file
Fig.1.3
Fig.1.2:Creation of new project

3.Select Device for target as AT89S51as shown in Fig. 1.4
Fig.1.4
4.Right click Source Group 1 and select Add new Item to Source Group 1
Fig.1.5

Choose file type as ASM ,name the file and click Add
Fig. 1.6
5.Type the code ,press F7/Bulid icon and Ctrl+F5 / Debug icon
Fig.1. 7
In Debug mode various simulations can be done with variety of tools like Logic Analyzer, Performance
Analyzer,etc.,Register and Memory status can be viewed during execution.
Fig. 1.6
Fig.1. 7
Fig. 1.6
Fig.1. 7

Logic Analyzer
 To perform Logic Analysis,Click View  Analysis WindowLogic Analyzer as shown in Fig 1.8
Fig. 1.8
The Logic Analyzer Window opens up.Click Setup and configure as shown below to observe waveform at P1.0
Fig. 9: Logic Analyzer Setup

Output waveform will be displayed as
Fig. 1.10: Logic Analyzer
Performance Analyzer
 To perform analysis of various parts of the program,Click View  Analysis Window Performance
Analyzer
 Click Setup and configure as follows
Fig. 1.11: Setup Performance Analyzer
 Output of performance is shown. Average execution time of a function and various other parameters
are shown to pave way for optimization
Fig. 1.12: Performance Analyzer
Analyzer
Analyzer

Register Window
Memory Window
 To access Memory Window,Click View  Memory Window  Memory 1
 We can view both code memory as well as data memory.
 Code memory contains the opcodes.Data memory contains the contents of RAM.
 To access code memory or data memory,use C: or D: followed by address.
Eg: C:0x00 D:0x00
Fig. 1.14 : Memory Window showing Code Memory
 To access Register Window ,Click View 
Register Window .
 Register window displays the contents of
Accumulator A ,register B,registers from R0
to R7,Program Status Word(PSW),Data
Pointer(DPTR),Stack Pointer(SP),Program
counter(PC),etc.,This makes program
debugging easier
Fig. 1.13 : Register Window
Fig. 1.15 : Memory Window showing Data Memory
Register Window
Memory Window
Eg: C:0x00 D:0x00
Register Window .
debugging easier
Register Window
Memory Window
Eg: C:0x00 D:0x00
Register Window .
debugging easier

Disassembly Window
 Click View  Disassembly Window.
 Disassembly Window shows the opcodes for each instruction.
Fig. 1.16: Disassembly Window
Serial Window
 Click View  Serial Windows  UART #1
 This is useful for simulating Serial communication before downloading it to microcontroller.
Fig. 1.17 : Serial Window
Breakpoints
 Program can be made to stop at a particular instruction so as to know the status of memory and
registers at that point.
 To insert a breakpoint place on a particular line or instruction and press F9.Pressing F9 again will
remove the breakpoint.
 Multiple breakpoints can be inserted and program will stop at breakpoints when run.
Disassembly Window
Serial Window
Breakpoints
Disassembly Window
Serial Window
Breakpoints

Fig. 1.18 Program having breakpoints at Line 4,11 and 13
Generating HEX file
To download the compiled program into the 8051 ,HEX file needs to be generated.To generate HEX
file ,click Flash  Configure Flash Tools
Fig. 1.19
A dialog box opens up.Click the Output tab and check in Create HEX fileoption.ClickOK.
Fig.1.20

Press F7/Bulid icon . Generated HEX file can be found in the Objects folder
Fig. 1.21 : HEX file in Objects folder
Fig.1. 22:Contents of the HEX file
Writing a sample program for blinking 8 LEDs connected to PORT 1 of 8051 periodically in Keil µVision IDE….
Additional software required: DLL files for LED simulation ( LED_CONTROL.DLL and LED_DATABASE.CDB )
ALGORITHM:
1. Start
2. Load 0xFF to Port 1.
3. Call Delay routine.
4. Load 0x00 to Port 0.
6. Goto Start
ALGORITHM:
1. Start
6. Goto Start
ALGORITHM:
1. Start
6. Goto Start

PROGRAM:
ORG 0x0000
START:MOV P1,#0xFF
ACALL DELAY
MOV P1,#0x00
ACALL DELAY
AJMP START
DELAY:MOV R0,#0xFF
L2:MOV R1,#0xFF
L1:DJNZ R1,L1
DJNZ R0,L2
RET
SIMULATION:
 Create a new project , add a new assembly file, type the above code and save it.
 To simulate the blink LED program, we have to download DLL for LED control from Keil website.
 Copy the LED_CONTROL.DLL and LED_DATABASE.CDB file to KeilC51BIN directory.
 Add this line to [C51] section of Tools.ini in Keil directory.
AGSI2=LED_CONTROL.DLL ("LED simulation")
 Restart Keil µVision IDE.
 With the project open, press Ctrl+F5 to Enter debug mode.
 Click Peripherals  LED. The LED Window opens up.
 Right Click and select add LED.New LED window opens up as shown in Fig. 1.23
Fig. 1.23

 Setup the pins for LED as shown in Fig 1.24
Fig. 1.24
 Similarly do the same for P1.1 ,P1.2,….P1.7
Fig. 1.25
 Press F5 to run the program.
RESULT:
Thus the development, debugging features of Keil µVision IDE were studied and a sample program for blinking
LED was executed.
Fig. 1.24
Fig. 1.25
RESULT:
LED was executed.
Fig. 1.24
Fig. 1.25
RESULT:
LED was executed.

ASSEMBLY LANGUAGE PROGRAMMING IN 8051
A.Timers /Counters
AIM:
i. To operate the timer0 in mode 0 and generate square wave of 66 % duty cycle.
ii. To operate the timer1 in mode 2 and generate a delay of 100 µs.
iii. Count clock pulses on P3.4 (T0 pin) and put it on Port 2
PROGRAM:
i. For generating square wave of 66 % duty cyle using timer 0 in mode 0
L1:
SETB P1.5
ACALL DELAY1
CLR P1.5
ACALL DELAY2
SJMP L1
DELAY1:
MOV TH0,#0x00 ;8 bit TH0 value
MOV TL0,#0x00 ;5 bit TL0 value
SETB TR0 ;Start timer
L2: JNB TF0,L2 ;Poll TF0 flag
CLR TR0
CLR TF0
RET
DELAY2:
MOV TH0,#0x80 ;8 bit TH0 value
MOV TL0,#0x00 ;5 bit TL0 value
SETB TR0 ;Start timer
L3: JNB TF0,L3 ;Poll TF0 flag
CLR TR0
CLR TF0
RET
OUTPUT:
Figure 2.1 Waveform at P1.5
Ex No.2
10-10-2015

15EE51 –Microcontrollers Laboratory Page 15
PROGRAM:
MOV TMOD,#0x20 ;Timer 1 in 8 bit autoreload mode (mode 2)
MOV TH1,#-92 ;100 µs /1.085 µs = 92 , 11.0592MHz ==> 1.085 µs
LOOP:SETB P1.2
ACALL DELAY
CLR P1.2
ACALL DELAY
SJMP LOOP
DELAY:SETB TR1 ;Start timer 1
L1:JNB TF1,L1 ; Poll TF1 flag
CLR TF1
CLR TR1
RET
OUTPUT:
Figure 2.2 Timer 1 registers

PROGRAM:
MOV TMOD,#0x50 ; Counter 1 ,8 bit mode
MOV TH1,#0x00 ; Autoreload value
SETB P3.5
AGAIN:SETB TR1
BACK:MOV A,TL1
MOV P2,A
JNB TF1,BACK
CLR TR1
CLR TF1
SJMP AGAIN
OUTPUT:
Figure 2.4

B.Serial Communication
AIM:
To turn on and turn off LEDs connected at PORT 1 by using serial communication. If ‘y’ is sent LEDs are turned on
and if ‘n’ is sent LEDs are turned off.Acknowledgment messages are also end.
PROGRAM:
ORG 0x00
MOV TMOD,#0x20 ; Timer 1, 8 bit autoreload
MOV SCON,#0x50 ; 8 bit,1 stop bit,Receive enabled
MOV TH1,#-3 ; 9600 baud rate for 11.0592 MHz
SETB TR1
WAIT:JNB RI,WAIT ;Poll RI flag bit
MOV R0,SBUF
CLR RI
CJNE R0,#'y',C1 ;If ‘y’ turn on LED
MOV P1,#0x00
SJMP DISPLAY_ON
C1:CJNE R0,#'n',C2 ;If ‘n’ turn off LED
MOV P1,#0xFF
SJMP DISPLAY_OFF
C2:SJMP WAIT
STRING1:DB "LEDs ON",10,0
STRING2:DB "LEDs OFF",10,0
DISPLAY_ON:MOV DPTR,#STRING1
SJMP SEND
DISPLAY_OFF:MOV DPTR,#STRING2
SJMP SEND
SEND:CLR A
MOVC A,@A+DPTR
JZ WAIT
MOV SBUF,A ;Place character to be transmitted in SBUF
WT:JNB TI,WT ;Poll TI flag bit
CLR TI
INC DPTR
SJMP SEND

OUTPUT:
Figure 2.5 (a) Serial Communication
Figure 2.5 (b) Serial Communication

C.Interrupts
AIM:
To write a program for demonstrating external interrupt (edge triggered at P3.2) , timer overflow interrupt(Timer 0)
and serial communication interrupt.
PROGRAM:
ORG 0x0000 ;RESET INTERRUPT
LJMP MAIN
ORG 0x0003 ;EXTERNAL INTERRUPT 0
CPL P1.0
RETI
ORG 0x000B ;TIMER 0 OVERFLOW INTERRUPT
CPL P1.1
RETI
ORG 0x0023 ;SERIAL COMMUNICATION INTERRUPT
LJMP SERIAL_ISR
ORG 0x0030
MAIN:
MOV SCON,#0x50
MOV IE,#0x93 ;ENABLE EXT ,TIMER 0 , SERIAL INTERRUPT
MOV TMOD,#0x22
MOV TH0,#0x00
MOV TH1,#-3
SETB TR0
SETB TR1
SETB IT0 ;EDGE TRIGERRED EXT. INTERRUPT
HERE:SJMP HERE
SERIAL_ISR:
CLR RI
MOV R0,SBUF
CJNE R0,#'y',C1
MOV P2,#0x00
C1:CJNE R0,#'n',C2
MOV P2,#0xFF
C2:RETI

External interrupt toggles the LED connected with P1.0 , timer overflow interrupt will generate square wave P1.1
and serial interrupt for turning ON and OFF LEDs at Port 2
OUTPUT:
Figure 2.6(a) Windows showing Interrupts,Serial Communication
Figure 2.6(b) Windows showing Interrupts,Serial Communication

RESULT:
Thus programs for Timers/Counters, Serial Communication and Interrupts were written in assembly and
simulated using Keil µVision IDE.

A. Timers /Counters
AIM:
i. To operate the timer0 in mode 0 and generate square wave of 66 % duty cycle.
PROGRAM:
i. For generating square wave of 66 % duty cycle using timer 0 in mode 0
C CODE:
#include<reg51.h>
void delay1();
void delay2();
void main()
{
while(1)
{
P1|=(1<<5); //Set bit P1.5
delay1();
P1&=~(1<<5); //Clear bit P1.5
delay2();
}
}
void delay1()
{
TH0=0x00;
TL0=0x00;
TR0=1; //Start Timer 0
while(!TF0); //Poll TF0 flag
TR0=0;
TF0=0;
}
void delay2()
{
TH0=0x80;
TL0=0x00;
TR0=1; //Start Timer 0
TR0=0;
TF0=0;
}
C LANGUAGE PROGRAMMING IN 8051Ex No.3
12-11-2015

C PROGRAMMING IN 8051
OUTPUT:
C CODE:
#include<reg51.h>
void delay();
void main()
{
TH1=-92; // 100 µs/1.085 µs = 92 for 11.592 MHz
TMOD=0x20;
while(1)
{
P1|=(1<<2); //Set bit P1.2
delay();
P1&=~(1<<2); //Clear bit P1.3
delay();
}
}
void delay()
{
TR1=1;
TF1=0;
TR1=0;
}

OUTPUT:
Figure 3.2 (a) Timer registers
Figure 3.2 (b) Timer registers
C CODE:
#include<reg51.h>
void main()
{
TMOD=0x50; //Counter 1 ,Mode 1
TH1=0x00;
T0=1;
while(1)
{
TR1=1;
while(!TF1)
P2=TL1;
TR1=0;
TF1=0;
}
}

OUTPUT:
Figure 3.3 Counter output

B. Serial Communication
AIM:
To turn on and turn off LEDs connected at PORT 1 by using serial communication. If ‘y’ is sent LEDs are turned on
and if ‘n’ is sent LEDs are turned off.Acknowledgment messages ”LEDs ON” and “LEDs OFF” are also sent.
C CODE:
#include<reg51.h>
void Serial_Init();
void Serial_Str_Transmit(char *);
char Serial_Char_Receive();
void main()
{
char ch;
Serial_Init();
while(1)
{
ch=Serial_Char_Receive();
switch(ch)
{
case 'y':
P1=0x00;
Serial_Str_Transmit("LEDs ONn");
break;
case 'n':
P1=0xFF;
Serial_Str_Transmit("LEDs OFFn");
break;
}
}
}
void Serial_Init()
{
TMOD=0x20;
SCON=0x50;
TH1=-3; // 9600 baud rate for 11.0592 MHz
TR1=1;
}
char Serial_Char_Receive()
{
while(!RI); //Poll RI flag
RI=0; //Clear RI flag
return(SBUF);
}

void Serial_Str_Transmit(char *p)
{
while(*p!='0')
{
SBUF=*p;
while(!TI); //Poll TI flag
TI=0;
p++;
}
}
OUTPUT:
Figure 3.4 Serial Communication

C. Interrupts
AIM:
To write a program for demonstrating external interrupt (edge triggered at P3.2) , timer overflow interrupt(Timer 0)
and serial communication interrupt.
C CODE:
#include<reg51.h>
void Serial_Init();
void Interrupt_Init();
void Timer0_Init();
void main()
{
Serial_Init();
Interrupt_Init();
Timer0_Init();
while(1); // Wait forever
}
void Serial_Init()
{
TMOD=0x20;
SCON=0x50;
TH1=-3;
TR1=1;
}
void Interrupt_Init()
{
IE=0x93;
IT0=1;
}
void Timer0_Init()
{
TMOD|=0x02;
TR0=1;
}
void ext_int0(void) interrupt 0 //Ext.Interrupt 0
{
P1^=(1<<0);
}
void timer_int0(void) interrupt 1 //Timer interrupt 0
{
P1^=(1<<1);
}

void serial_int(void) interrupt 4 //Serial Interrupt
{
RI=0;
if(SBUF=='y')
P2=0x00;
if(SBUF=='n')
P2=0xFF;
}
External interrupt toggles the LED connected with P1.0 , timer overflow interrupt will generate square wave P1.1
and serial interrupt for turning ON and OFF LEDs at Port 2
OUTPUT:
Figure 3.5 External ,Timer and Serial Communication interrupt
RESULT:
Thus assembly and C programs for Timers/Counters, Serial Communication and Interrupts in 8051
microcontroller were written and simulated using Keil µVision IDE.

AIM:
i. To turn on only RED LED (P1.4) when key 1(P2.0) is pressed and turn only GREEN LED(P1.5)
when key 2(P2.1) is pressed
ii. To produce a single beep sound when key 1 is pressed and a double beep sound when key 2 is
pressed.
iii. To interface HD44780 compatible 16 × 2 LCD display in 8 bit mode.
iv. To interface a 4 × 4 Matrix keypad.
PROGRAM:
i. To write a program to turn on only RED LED (P1.4) when key 1(P2.0) is pressed and turn only
GREEN LED(P1.5) when key 2(P2.1) is pressed.
#include<reg51.h>
sbit RED =P1^4;
sbit GREEN =P1^5;
sbit KEY1=P2^0;
sbit KEY2=P2^1;
void main()
{
while(1)
{
if(!KEY1)
{
RED=0;
GREEN=1;
}
if(!KEY2)
{
RED=1;
GREEN=0;
}
}
4. INTERFACING HARDWARE WITH 8051
Ex No : 4
16-11-15

INTERFACING HARDWARE WITH 8051
OUTPUT:
ii. To produce a beep sound when key 1 is pressed and a beep sound twice when key 2 is
pressed.
#include <reg51.h>
void beep();
void delay_ms(int d);
sbit BUZZER = P3^4;
void main()
{
while(1)
{
if(!KEY1)
{
beep();
}
if(!KEY2)
{
beep();
delay_ms(200);
beep();
}
}
Fig 4.1 RED LED glowing when Key1 is pressed Fig 4.2 GREEN LED glowing when Key2 is pressed

void beep()
{
unsigned char i = 25;
while (i--)
{
BUZZER = !BUZZER;
delay(5);
}
}
void delay_ms(int d)
{
int i;
TCON=0x01;
for(i=0;i<d;i++)
{
TH0=0x01;
TL0=0x40;
TR0=1;
while(!TF0);
TR0=0;
}
}
iii. To interface HD44780 compatible 16 × 2 LCD display in 8 bit mode.
#include<reg51.h>
sbit RS =P2^4;
sbit RW=P2^5;
sbit EN=P2^6;
#define CLEAR 0x01
void LCD_Init();
void LCD_SetCursor(char,char);
void LCD_Cmd(char);
void LCD_Data(char);
void LCD_PrintChar(char);
void LCD_PrintStr(char*);
void delay_ms(int);

void main()
{
RW=0;
LCD_Init();
LCD_PrintStr("Jabez Winston");
delay_ms(1000);
LCD_SetCursor(1,0);
LCD_PrintChar("Jagdeesh");
while(1);
}
void LCD_Init()
{
delay_ms(100);
LCD_Cmd(0x38);
delay_ms(10);
LCD_Cmd(0x0C);
LCD_Cmd(0x06);
LCD_Cmd(CLEAR);
}
void LCD_SetCursor(char r,char c)
{
switch(r)
{
case 0: LCD_Cmd(0x80+c);
break;
case 1: LCD_Cmd(0xC0+c);
break;
}
}
void LCD_Cmd(char cmd)
{
EN=0;
RS=0;
P1=cmd;
EN=1;
delay_ms(10);
EN=0;
}

void LCD_Data(char ch)
{
EN=0;
RS=1;
P1=ch;
EN=1;
delay_ms(10);
EN=0;
}
void LCD_PrintChar(char ch)
{
LCD_Cmd(ch);
}
void LCD_PrintStr(char *s)
{
while(*s)
LCD_PrintChar(*s++);
}
void delay_ms(int d)
{
int i;
TCON=0x01;
for(i=0;i<d;i++)
{
TH0=0x01;
TL0=0x40;
TR0=1;
while(!TF0);
TR0=0;
}
}

OUTPUT:
Figure 4.3 Two strings printed on LCD
iv. To interface a 4 × 4 Matrix keypad.
#include<reg51.h>
unsigned char get_key();
void lcd_init();
void lcd_printc(char);
void lcd_prints(char);
void lcd_clear();
void lcd_write_cmd(unsigned char );
void lcd_write_data(unsigned char );
void delay(int);
sbit LCD_RS = P2^4;
sbit LCD_WR = P2^5;
sbit LCD_EN = P2^6;
int x;
char a[4][4]={"123E",
"456U",
"789D",
"*0#e"};

void main()
{
lcd_init();
while(1)
{
while(get_key()==-1);
x=get_key();
lcd_printc(x);
delay(100);
}
}
unsigned char get_key()
{
unsigned char i,j,k;
for(i=0;i<4;i++)
{
P1=~(1<<i);
delay(20);
for(j=4;j<=7;j++)
{
if(!((P1)&(1<<j)))
{
k = a[i][j-4];
return k;
}
}
}
return -1;
}
void lcd_init()
{
delay(15); // LCD Power on delay
lcd_write_cmd(0x38); // 8BIT, 2 LINE , 5x8 DOT Format font
delay(5); // Small delay
lcd_write_cmd(0x38);
lcd_write_cmd(0x0c);
lcd_write_cmd(0x0E);
lcd_clear();

}
void lcd_printc(char a_char)
{
lcd_write_data(a_char);
}
void lcd_prints(char *string)
{
while (*string)
lcd_printc(*string++);
}
void lcd_clear()
{
}
void lcd_write_cmd(unsigned char cmd)
{
delay(10);
LCD_WR = 0;
LCD_EN = 0;
LCD_RS = 0; // Reset LCD_RS for Command
P0 = cmd;
LCD_EN = 1; // Pulse LCD_EN
LCD_EN = 0;
LCD_WR = 1;
}
void lcd_write_data(unsigned char val)
{
delay(10);
LCD_WR = 0;
LCD_EN = 0;
LCD_RS = 1; // SET LCD_RS for DATA
P0 = val;
LCD_EN = 1; // Pulse LCD_EN
LCD_EN = 0;
LCD_WR = 1;
}

void delay(unsigned int dval)
{
TMOD &= 0xF0;
TMOD |= 0x01;
while (dval) {
TR0 = 0;
TF0 = 0;
TH0 = 0xFA;
TL0 = 0x00;
TR0 = 1;
while (TF0 == 0);
dval--;
}
TR0 = 0;
}
Fig 4.4 Matrix keypad and 16 x 2 LCD display
RESULT:
Thus LED,buzzer,matrix keypad and LCD were interfaced with 8051 starter kit.

15EE51 - Microcontrollers Laboratory

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