em lab m.tech

7/27/2019 em lab m.tech

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INDEX

I Cycle

1. SERIAL COMMUNICATION............................................................2

1(a) SERIAL COMMUNICATION (continuous display of one character)...........2

1(b) SERIAL COMMUNICATION (display of one name)...................................4

1(c) SERIAL COMMUNICATION (without using arrays display your name).. ...6

2(b) Real Time Timer.....................................................................................8

3. LOOK UP TABLE........................................................................11

4. LCD INTERFACE TO 8051...........................................................15

5. ADC& DAC INTERFACE TO 8051.................................................18

5a) ADC.......................................................................................................18

AIM: To write an 8051 embedded c code for ADC & DAC Interface to 805118

5b) DAC....................................................................................................... 20

6. KEYBOARD...............................................................................23

6a) Keyboard interface to 8051..................................................................23

6b) Interfacing to keyboard using switch case............................................26

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1. SERIAL COMMUNICATION

1(a) SERIAL COMMUNICATION (continuous display of one character)

AIM: To write an 8051embedded c code for the continuous display of oneCharacter

HARDWARE TOOLS

PCMicro Controller Evaluation Board

Power Supply

SOFTWARE TOOLS:

IDE- Keil vision

Programming tool: ATMEL FLIP

THEORY:

Serial communication is the process of sending data one bit at a time, sequentially, over a

communication channel or computer bus. This is in contrast to Parallel communication,where several bits are sent as a whole, on a link with several parallel channels. Serial

communication is used for all long-haul Communication and most computer networks,

where the cost of cable and Synchronization difficulties make parallel communication

impractical. Serial Computer buses are becoming more common even at shorterdistances, as Improved signal integrity and transmission speeds in newer serial

technologies have begun to outweigh the parallel bus's advantage of simplicity (no need

for serializer and deserializer, or SerDes) and to outstrip its disadvantages (clock skew,

Interconnect density). The migration from PCI to PCI Express is an example.

PROCEDURE:

1) Write the code using Keil vision IDE

2) Complete the code

3) Connect the power supply to the evaluation board and switch on the power supply4) Connect the standard RS232 cross cable between the computers serial port and the

board

5) Using the programming tool Atmel flip port the program code on to the

Microcontroller evaluation board6) Result obtained is viewed in corresponding ports

SOURCE CODE:

#include

void main ()

{TMOD=0x20;

SCON=0x50;

TH1=0xFD;

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TR1=1;

while (1)

{SBUF='A';

while (TI==0);

TI=0;}

}

RESULT: Hence the 8051 embedded c code for the continuous display of oneCharacter is verified

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1(b) SERIAL COMMUNICATION (display of one name)

AIM: To write an 8051 embedded c code for the display of one character

HARDWARE TOOLS

PC

Micro Controller Evaluation BoardPower Supply

SOFTWARE TOOLS:

IDE- Keil vision


THEORY:

Serial communication is the process of sending data one bit at a time, sequentially, over acommunication channel or computer bus. This is in contrast to Parallel communication,

where several bits are sent as a whole, on a link with several parallel channels. Serialcommunication is used for all long-haul Communication and most computer networks,

where the cost of cable and Synchronization difficulties make parallel communication

impractical. Serial Computer buses are becoming more common even at shorterdistances, as Improved signal integrity and transmission speeds in newer serial

technologies have begun to outweigh the parallel bus's advantage of simplicity (no need

for serializer and deserializer, or SerDes) and to outstrip its disadvantages (clock skew,Interconnect density). The migration from PCI to PCI Express is an example.

PROCEDURE:1) Write the code using Keil vision IDE2) Complete the code

3) Connect the power supply to the evaluation board and switch on the power supply

4) Connect the standard RS232 cross cable between the computers serial port and theboard



SOURCE CODE:#include

#include

void serail_init (void);void serial_init (void)

{

SCON=0x20;TMOD=0x20;

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TH1=0xFD;

TR1=1;

TI=1;}

void main (void)

{

serial_init ();

while (1){printf ("Hello! World\n");

}

}

RESULT: Hence the 8051 embedded c code for the display of one nameis verified

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1(c) SERIAL COMMUNICATION (without using arrays

display your name)

AIM: To write an8051 embedded c code for the without using arrays display your name

HARDWARE TOOLS

PC

Micro Controller Evaluation Board

Power Supply

SOFTWARE TOOLS:

IDE- Keil vision


THEORY:

Serial communication is the process of sending data one bit at a time, sequentially, over acommunication channel or computer bus. This is in contrast to Parallel communication,

where several bits are sent as a whole, on a link with several parallel channels. Serial

communication is used for all long-haul Communication and most computer networks,where the cost of cable and Synchronization difficulties make parallel communication

impractical. Serial Computer buses are becoming more common even at shorter

distances, as Improved signal integrity and transmission speeds in newer serial

technologies have begun to outweigh the parallel bus's advantage of simplicity (no needfor serializer and deserializer, or SerDes) and to outstrip its disadvantages (clock skew,

Interconnect density). The migration from PCI to PCI Express is an example.

PROCEDURE:


2) Complete the code3) Connect the power supply to the evaluation board and switch on the power supply

4) Connect the standard RS232 cross cable between the computers serial port and the

board

5) Using the programming tool Atmel flip port the program code on to theMicrocontroller evaluation board

6) Result obtained is viewed in corresponding ports

SOURCE CODE:

#includevoid SerTx (unsigned char);

void main (void)

{TMOD=0X20;

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TH1=0XFD;

SCON=0X50;

TR1=1;while (1)

{

SerTx ('C');SerTx ('M');

SerTx ('R');

SerTx ('E');SerTx ('C');

}

}

void SerTx (unsigned char x){

SBUF=x;

while (TI==0);

TI=0;}

RESULT: Hence the 8051 embedded c code for the without using arrays display yourname is verified

2.TIMERS

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2. TIMER

2(b) Real Time Timer

AIM: To study and verify Real time timer

HARDWARE TOOLS

PC Micro Controller Evaluation Board

Power Supply

SOFTWARE TOOLS:

IDE- Keil vision


THEORY:Timer is a clock that controls the sequence of an event while counting in fixed intervals

of time. A Timer is used for producing precise time delay. Secondly, it can be used torepeat or initiate an action after/at a known period of time. This feature is very commonly

used in several applications. An example could be setting up an alarm which triggers at a

point of time or after a period of time.

Most of the microcontrollers have inbuilt Timers. Timers in a controller not only generate

time delays but they can also be used as counters. They are used to count an action orevent. The value of counter increases by one, every time its corresponding action or event

occurs. Timers in a controller are inbuilt chips that are controlled by special function

registers (SFRs) assigned for Timer operations. These SFRs are used to configure Timersin different modes of operations.While working with microcontrollers, it is more than often required to generate time

delays. There are two possible ways of generating time delays. First is by using the code,

like using for or while loops in a C program. However, the delays provided by thesoftware are not very precise. The other method is to use Timers. Timers provide timedelays that are very precise and accurate.

Microcontroller has two Timers designated as Timer0 and Timer1. Each of these timers isassigned a 16-bit register. The value of a Timer register increases by one every time a

timer counts. Timer takes a time period of one machine cycle to count one. This means

that the maximum number of times a timer can count without repeating is 216, i.e.,

65536. So the maximum allowed counts in value of Timer registers can be from 0000H toFFFFH. Since 8051 is an 8 bit controller, the registers of 8051 Timers are accessed as

two different registers; one for lower byte and other for higher byte. For example, register

of Timer0 is accessed as TL0 for lower byte and TH0 for higher byte. Similarly TL1 and

TH1 are registers assigned to Timer 1.

While using 8051 Timers certain factors need to be considered, like whether the Timer is

to be used for time keeping or for counting; whether the source for time generation is

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http://www.engineersgarage.com/microcontrollerhttp://www.engineersgarage.com/microcontroller


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external clock or the controller itself; how many bits of Timer register are to be used or

left unused.

The registers of Timers are loaded with some initial value. The value of a Timer registerincreases by one after every machine cycle. One machine cycle duration is the 1/12th of

the frequency of the crystal attached to the controller.

A register called TMOD is used for configuring the Timers for the desired operation.

TMOD is an 8-bit register with following bit configuration:

The lower four bits (TMOD.0 TMOD.3) are used to configure Timer 0 while the higherfour bits (TMOD.4 TMOD.7) are for Timer 1. When GATE is high, the corresponding

Timer is enabled only when there is an interrupt at corresponding INTx pin of AT89C51

controller and Timer control bit is high. Otherwise only setting Timer control bit is

sufficient to start the Timer.

PROCEDURE:




board5) Using the programming tool Atmel flip port the program code on to the

microcontroller evaluation board


SOURCE CODE:

Timer interrupts

#include

#includesbit pin=P1^5;

void timer1_int ();

void main (){

AUXR=0x10;

EA=1;timer1_int ();

While (1);

}

Void timer1_int (){

TMOD=0x10;

TH1=0x4B;TL1=0xFE;

TR1=1;

ET1=1;}

timer1_isr () interrupt 3

{

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pin=~pin;

TF1=0;

TH1=0x4B;TL1=0xFE;

}

Timer 0 Interrupt

#include#include

sbit pin=P1^5;

void timer0_int ();

void main (){

timer0_int ();

EA=1;

while (1);}

void timer0_int (){

TMOD=0x02;

TH0=0x4B;

TL0=0xFE;TR0=1;

ET0=1;

}timer0_isr () interrupt 1

{

pin=~pin;TF0=0;

TH0=0x4B;

TL0=0Xff;}

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3. LOOK UP TABLE

AIM: To write an 8051 embedded c code for the look up table

HARDWARE TOOLS


Power Supply

SOFTWARE TOOLS:

IDE- Keil vision Programming tool: ATMEL FLIP

THEORY:

A lookup table is a data structure, usually an array or associative array, often used toreplace a runtime computation with a simpler array indexing operation. The savings in

terms of processing time can be significant, since retrieving a value from memory is oftenfaster than undergoing an 'expensive' computation or input/output operation. The tables

may be pre calculated and stored in static program storage or calculated (or "perfected")

as part of a programs initialization phase (memorization). Lookup tables are also usedextensively to validate input values by matching against a list of valid (or invalid) items

in an array and, in some programming languages, may include pointer functions (or

Offsets to labels) to process the matching input

PROCEDURE:

1) Write the code using Keil vision IDE2) Complete the code3) Connect the power supply to the evaluation board and switch on the power supply



microcontroller evaluation board

6) Result obtained is viewed in corresponding ports.

SOURCE CODE:

#include

#include#include

void start (void);

unsigned char ReadNVROM (void);void Stop (void);

#define ACK 1

#define NO_ACK 0#define SLAVE 0xa0

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#define WRITE 0x00

#define READ 0x01

void DelayUs (int us);unsigned char i;

void DelayMs (unsigned int count);

sbit SDA=P1^0;sbit SCL=P1^1;

write NVROM (NVROM_ARR);

void InitSerial (void);unsigned char NVROM_ARR, temp1, temp2;

void main ()

{

char AUXR;AUXR=0x10;

NVROM_ARR=0x00;

while (1)

{Write NVROM (NVROM_ARR);

NVROM_ARR+=1;DelayMs (5);

temp1=ReadNVROM ();

temp2=temp1;

temp2 &=0xf0;temp2>>=4;if(temp2


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DelayUs (1);

SDA=0;

DelayUs (1);SCL=0;

DelayUs (1);

}void Stop (void)

{

SDA=0;DelayUs (1);

SCL=1;

DelayUs (1);

SDA=1;}

void WriteI2C (unsigned char Data)

{

for (i=0; i


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return Data;

}

unsigned char ReadNVROM (void){

unsigned char buff;

void Start ();WriteI2C (0xa0);

WriteI2C (0x00);

Start ();WriteI2C (0xa1);

buff=ReadI2C (ACK);

Stop();

return (buff);}

void WriteNVROM (unsigned char buff)

{

Start();WriteI2C (0xa0);

WriteI2C (0x00);WriteI2C (buff);

Stop ();

}

void InitSerial(void){

SCON=0x52;

TMOD=0x20;TH1=0xFD;

TR1=1;

}void DelayMs (unsigned int count)

{

unsigned int i;while (count)

{

i=115;

while (i>0)i--;count --;

}

}void DelayUs (int us)

{

int i;for (i=0; i


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4. LCD INTERFACE TO 8051

AIM: To write an 8051 embedded c code for LCD display

HARDWARE TOOLS:


Power Supply

SOFTWARE TOOLS:

IDE- Keil vision


THEORY:A liquid crystal display (LCD) is a flat panel display, electronic visual display, video

display that uses the light modulating properties of liquid crystals (LCs). LCs do not emitlight directly. They are used in a wide range of applications, including computer

monitors, television, instrument panels, aircraft cockpit displays, signage, etc. They are

common in consumer devices such as video players, gaming devices, clocks, watches,calculators, and telephones. LCDs have displaced cathode ray tube (CRT) displays in

most applications. They are usually more compact, lightweight, portable, less expensive,

more reliable, and easier on the eyes. They are available in a wider range of screen sizes

than CRT and plasma displays, and since they do not use phosphors, they cannot sufferimage burning.

LCDs are more energy efficient and offer safer disposal than CRTs. Its low electricalpower consumption enables it to be used in battery-powered electronic equipment. It is anelectronically modulated optical device made up of any number of segments filled with

liquid crystals and arrayed in front of a light source (backlight) or reflector to produce

images in color or monochrome. The most flexible ones use an array of small pixels.

PROCEDURE:


2) Complete the code3) Connect the power supply to the evaluation board and switch on the power

supply

4) Connect the standard RS232 cross cable between the computers serial portand the board



SOURCE CODE:

#include

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#include

sbit rs = P2^7;

sbit en = P2^5;sbit rw = P2^6;

sbit b = P0^7;

void writecmd (unsigned char a);void writedat (unsigned char b);

void busy ();

void writestr (unsigned char *s);void writecmd (unsigned char a)

{

busy ();

rs = 0;rw = 0;

P0 = a;

en = 1;

en = 0;}

void writedat (unsigned char b){

busy ();

rs = 1;

rw = 0;P0 = b;

en = 1;

en = 0;}

void busy ()

{en = 0;

P0 = 0xFF;

rs = 0;rw = 1;

while (b==1)

{

en=0;en=1;

}

en=0;}

void writestr (unsigned char *s)

{unsigned char l, i;

l = strlen(s);

for (i=1; i


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Writedat (*s);

s++;

}}

main ()

{P0=0x00;

P2=0x00;

writecmd (0x3C);writecmd (0x0E);

writecmd (0x01);

writestr ("Wel-Come to LCD");

writecmd (0xC4);writestr ("Program");

while (1);

}

RESULT: Hence the embedded c code for LCD display is verified

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5. ADC& DAC INTERFACE TO 8051

5a) ADC

AIM: To write an 8051 embedded c code for ADC & DAC Interface to 8051

HARDWARE TOOLS


Power Supply

SOFTWARE TOOLS:

IDE- Keil vision


THEORY:An analog-to-digital converter (abbreviated ADC, A/D or A to D) is a device that

converts a continuous quantity to a discrete time digital representation. An ADC may alsoprovide an isolated measurement. Typically, an ADC is an electronic device that converts

an input analog voltage or current to a digital number proportional to the magnitude of

the voltage or current. However, some non-electronic or only partially electronic devices,such as rotary encoders, can also be considered ADCs. The digital output may use

different coding schemes.

Typically the digital output will be a two's complement binary number that is

proportional to the input, but there are other possibilities. An encoder, for example, mightoutput a Gray code.

PROCEDURE:1) Write the code using Keil vision IDE2) Complete the code


4) Connect the standard RS232 cross cable between the computers serial port and theboard


microcontroller evaluation board6) Result obtained is viewed in corresponding ports

SOURCE CODE:

#include

#include sbit wr = P3^0;

sbit rd = P3^1;

sbit d1 = P2^7;sbit d2 = P2^6 ;

unsigned char data d;

unsigned int a=0, b=0, c=0;void int1 (void) interrupt 1

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{

EA=0;

rd = 0;d=P1;

rd=1;

a = (d & 0x0F);b = d >> 4;

EA=1;

}void tmr1 (void) interrupt 3

{

c++;

TH1=0xEC;TL1=0x77;

TF1=0;

If ((c%2)==0)

{d1=1;

d2=0;P0=b;

} else

{

d1=0;d2=1;

P0=a;

}}

main ()

{P0=0x00;

P1=0xFF;

TMOD=0x90;TH1=0xEC;

TL1=0x77;

TR1=1;

d1=0;d2=1;

P0=a;

IE=0x89;wr = 0;

wr = 1;

while (1);}

RESULT: Hence the embedded c code for ADC is verified

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5b) DAC

AIM: To write an 8051 embedded c code for DAC

HARDWARE TOOLSPC


Power Supply

SOFTWARE TOOLS:

IDE- Keil visionProgramming tool: ATMEL FLIP

THEORY:

A DAC converts an abstract finite-precision number (usually a fixed-point binary

number) into a physical quantity (e.g., a voltage or a pressure). In particular, DACs areoften used to convert finite-precision time series data to a continually varying physical

signal. A typical DAC converts the abstract numbers into a concrete sequence ofimpulses that are then processed by a reconstruction filter using some form of

interpolation to fill in data between the impulses. Other DAC methods (e.g., methods

based on Delta-sigma modulation) produce a pulse-density modulated signal that canthen be filtered in a similar way to produce a smoothly varying signal. As per the

NyquistShannon sampling theorem, a DAC can reconstruct the original signal from the

sampled data provided that its bandwidth meets certain requirements (e.g., a basebandsignal with bandwidth less than the Nyquist frequency). Digital sampling introduces

quantization error that manifests as low-level noise added to the reconstructed signal.

PROCEDURE:




board

5) Using the programming tool Atmel flip port the program code on to theMicrocontroller evaluation board



void delay1 ();

void delay2 ();void sqrarwave ();

void triwave ();

void stairwave ();void delay1 ()

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{

int a, b;

for (a=0; a


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Delay2 ();

}

}void main ()

{

P2=0x00;P3=0xFF;

while (P3=0xFF);

switch (P3){

case 0xFE:

delay1 ();

P3=0xFF;squarwave ();

break;

case 0xFD:

delay1 ();P3=0xFF;

triwave ();break;

case 0xFB:

delay1 ();

P3=0xFF;stairwave ();

break;

}}

RESULT: Hence the embedded c code for the DAC is verified.

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6. KEYBOARD

6a) Keyboard interface to 8051

AIM: To write an 8051 embedded c code for the keyboard

HARDWARE TOOLS


Power Supply

SOFTWARE TOOLS:

IDE- Keil vision


THEORY:

In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of

buttons or keys, to act as mechanical levers or electronic switches.Following the decline of punch cards and paper tape, interaction via tele printer style

keyboards became the main input device for computers, despite the development of

alternative input devices, such as the mouse, touch screen, pen devices, character

recognition and voice recognition, the keyboard remains the most commonly used andmost versatile device used for direct (human) input into computers.

A keyboard typically has characters engraved or printed on the keys and each press of a

key typically corresponds to a single written symbol. However, to produce some symbols

requires pressing and holding several keys simultaneously or in sequence. While mostkeyboard keys produce letters, numbers or signs (characters), other keys or simultaneous

key presses can produce actions or computer commands.

PROCEDURE:

1) Write the code using Keil vision IDE2) Complete the code




microcontroller evaluation board6) Result obtained is viewed in corresponding ports

SOURCE CODE:

#include #define KEYPAD P1

#define display P3

void delay (int k)

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{

int i;

TR0=0;for(i=0; i


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colloc=KEYPAD & 0xF0;

if (colloc !=0xF0)

{rowloc=1;

goto next;

}KEYPAD=0xFB;


if (colloc !=0xF0){

rowloc=2;

goto next;

}KEYPAD=0xF7;


rowloc=3;

goto next;next:

if (colloc==0xE0)display= (keypad [rowloc][0]);

else if (colloc==0xD0)

display= (keypad[rowloc][1]);

else if (colloc==0xB0)display = (keypad [rowloc][2]);

}

}void DelayMs (unsigned int count)

{

unsigned int i;while count) {

i = 115;

while (i>0) i--;count--;

}

}

RESULT: Hence the embedded c code for the keyboard is verified.

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6b) Interfacing to keyboard using switch case

AIM: To write an 8051 embedded c code for keyboard using Switch Case

HARDWARE TOOLS

PC


SOFTWARE TOOLS:

IDE- Keil visionProgramming tool: ATMEL FLIP

THEORY:

In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of

buttons or keys, to act as mechanical levers or electronic switches. Following the declineof punch cards and paper tape, interaction via teleprinterstyle keyboards became the main

input device for computers.Despite the development of alternative input devices, such as the mouse, touch screen,

pen devices, character recognition and voice recognition, the keyboard remains the most

commonly used and most versatile device used for direct (human) input into computers.A keyboard typically has characters engraved or printed on the keys and each press of a

key typically corresponds to a single written symbol. However, to produce some symbols

requires pressing and holding several keys simultaneously or in sequence. While mostkeyboard keys produce letters, numbers or signs (characters), other keys or simultaneous

key presses can produce actions or computer commands.

PROCEDURE:




board

5) Using the programming tool Atmel flip port the program code on to themicrocontroller evaluation board



#include

char code column [] = {0xbf, 0xdf,0xef};void keypad (void) interrupt 2

{

char x, key;unsigned int k;

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EX1 = 0;

P1=0xff;

for (x=0; x

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