Interfacing with led

#include<reg51.h>

void main()
{
      while(1)
         {
            P1=0XFF;
            P1=0X00;
          }
}

 
 
 









Here #include<reg51.h> is the header file for 8051.

P1 state that port selection of 8051 .

0xFF means 0b11111111
0x00 means 0b00000000.

Temperature monitoring system using lm35 in atmega32

#include<avr/io.h>
#include<util/delay.h>
#include<stdio.h>
void cmd()
{
 PORTB=0x04;
 _delay_ms(150);
 PORTB=0x00;
}
void display()
{
 PORTB=0x05;
 _delay_ms(150);
 PORTB=0x01;
}
void lcdstring(unsigned char *p)
{
 while(*p!='\0')
 {
  PORTC=*p;
  display();
  p++;

 }
}
unsigned char arr[]={0x38,0x0e,0x80,0x06};
 unsigned int a;
 unsigned char res[4];
 int i;
 void main()
 {
  DDRA=0x00;
  DDRB=0xff;
  DDRC=0xff;
  for(i=0;i<=3;i++)
  {
 
   PORTC=arr[i];
   cmd();
  }
  lcdstring("Temperature is");
  ADMUX=0xc0;
  ADCSRA=(1<<ADEN)|(1<<0);


  while(1)
  {
 
   ADCSRA|=(1<<ADSC);
   while(!(ADCSRA&(1<<ADIF)));
   a=(ADC)/4;
   sprintf(res,"%d",a);
   PORTC=0xc0;
   cmd();
   lcdstring(res);
   }
 
 
 }

 

interfacing of LCD in 4 bit mode on same port in atmega16/32

#include <avr/io.h>
#include<util/delay.h>
#define rs PA0
#define rw PA1
#define en PA2
void cmd()
{
 PORTA&=(~(1<<rs));
 PORTA&=(~(1<<rw));
 PORTA|=(1<<en);
 _delay_ms(200);
 PORTA&=(~(1<<en));

}
void display()
{
 PORTA|=(1<<rs);
 PORTA&=(~(1<<rw));
 PORTA|=(1<<en);
 _delay_ms(200);

 PORTA&=(~(1<<en));
}
 unsigned char arr1[]={0x02,0x0e,0x01,0x80,0x06};
  unsigned char arr2[]={"welcome in TBA"};
void main()
{

 while(1)
 {

  int i;
  DDRA=0XFF;
  for(i=0;i<=5;i++)
  {
   PORTA=arr1[i]&0xf0;
   cmd();
   PORTA=(arr1[i]<<4)&0xf0;
   cmd();
  }
  for(i=0;i<=14;i++)
  {
   PORTA=arr2[i]&0xf0;
   display();
   PORTA=(arr2[i]<<4)&0xf0;
   display();
 
  }
  }
}

interfacing of LCD using arr

#include<avr/io.h>
#include<util/delay.h>
void cmd()
{

 PORTA=0B00000100;
 _delay_ms(300);
 PORTA=0B00000000;
}
     void display()
{
 PORTA=0B00000101;
 _delay_ms(300);
 PORTA=0B00000001;
}
 unsigned char arr1[]={0x38,0x0e,0x01,0x80,0x06};
  unsigned char arr3[]={"welcome in TBA"};
  
 
  void main ()
  {
   while(1)
   {
    int i;
   DDRA=0xff;
   DDRB=0xff;
   for(i=0;i<=4;i++)
   {
    PORTB= arr1[i];
    cmd();
   }   
    for(i=0;i<=14;i++)
   
   {
    PORTB=arr3[i];
    display();
   
   }
  
  }
  }
  

Interfacing of LCD and introduction.

Introduction of lcd and interfacing

Lcd(liquid crystal display):-

Series for embedded is

 16x1          means 1 row 16 columns

16x2           means 2 row 16 columns

16x4           means 4 row 16 columns

20x1           means 1 row 20 columns

20x2           means 2 row 20 columns

40x1           means 1 row 40 columns

40x2           means 2 row 40 columns

 

·       Lcd is a individually an embedded product. It is preceed 8-bit data at a time.

·       It has 8 select data line by this 8-bit data is transferred at a time.

·       In this 16 pin in which 15 and 16 pin is provide lcd backlight. Pin 1 and 2 provides power to lcd and 3^rd pin vee stands for variable resistance this is used for control the contrast of lcd.

·       Lcd have 2 registers

1.     Command register

2.    Data register

 Both registers are 8-bit.

Pin 4, 5 and 6 are RS, RW and EN

RS- Register select

Send 0 for command

Send 1 for data.

RW- READ WRITE

Send 1 for read

Send 0 for write

EN- ENABLE

send 1 for command

send 1 for data.

after giving delay enable will be zero.

 

LCD has some predefined commands:-

·       0x01 for clear display screen.

·       0x04 for decrement cursor.

·       0x06 for increment cursor.

·       0x80 force cursor to the beginning of first line.

·       0xc0 force cursor to the beginning of second line.

·       0x90 force cursor to the beginning of third line.

·       0xdo force cursor to the beginning of fourth line.

·       0x0e for display on cursor blinking.

·       0x0f for display on cursor not blinking.

·       0x02 for select 4 bit mode.

·       0x28 selects 5x7 matrix for 4 bit mode.

·       0x38 selects 5x7 matrix for 8 bit mode.

·       0x18 fir moving entire display left.

·       0x1c for moving entire display right.

 

We are using commonly these bold commands.

 

program to display A on LCD screen.

 

#include<avr/io.h>
#include<util/delay.h>
void cmd()
{
 PORTA=0B00000100;
 _delay_ms(300);
 PORTA=0b00000000;

}
void display()
{
 PORTA=0b00000101;
 _delay_ms(300);
 PORTA=0b00000001;

}
void main()
{
 DDRA=0xff;
 DDRB=0xff;
 PORTB=0X38;
 cmd();
 PORTB=0X0e;
 cmd();
 PORTB=0X01;
 cmd();
 PORTB=0X80;
 cmd();
 PORTB=0X06;
 cmd();
 PORTB='A';
 display();
}

 

interfacing of motor in atmega16/32

#include<avr/io.h>

#include<util/delay.h>
  void main()
{
DDRA=0XFF;

while(1)

{

PORTA=0x0a;
}
}

 

There are two types of motor generally used in embedded system:-

1.       DC motor

2.       Stepper motor

 

Commands for two DC motor:-

Forward = 10 10 = 0x0a

Backward = 01 01 = 0x05

Right move = 10 00 = 0x08

Left move = 00 10 = 0x02

Stop = 00 00 = 0x00

 

Using these commands operate two DC motors.

In proteus or hardware I need a motor driver to operate it that’s called L293D  in which 4 inputs and 4 outputs pins , 2 VCC pin , 4 pin for GND, 2 enable pin.  This is total 16 pin IC.

interfacing of switch with 7segment in atmega16/32

#include<avr/io.h>

#include<util/delay.h>
  int arr[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};

void main()

{
int i;

while(1)

{

DDRA=0XFF;

DDRC=0X00;

if(PINC&0X01)

{

for(i=0;i<=9;i++)

{

PORTA=arr[i];

_delay_ms(1000);

}

}

else

{

PORTA=0X00;

}

}
}

  

In this we are using int arr[]={…………….}; means hex form of 0-9 on segment .

format:-

0= 0x3F

1= 0X06

2 = 0X5B

3= 0X4F

4= 0X66

5= 0X6D

6= 0X7D

7= 0X07

8= 0X7F

9=0X6F

And for loop is using for complete the loop 0-9.

PINC&0X01 means PC0 is active high and by this way we can make high any pin as a switch.

And according to this program we can write more for programs  Like as using 2 segments and two switch. Like as 1 segment using two switch. Using more loops  etc.

 
 


 

interfacing of switch in atmega16/32

#include <avr/io.h>

void main()

{

while(1)

{

DDRA=0XFF;

DDRC=0X00;

{

if(PINC&0X01)

{

PORTA=0b00000001;

}

else

{

PORTA=0X00;

}
}
}
}

In this we are using PORTC=0x00 means as input port and PORTA as output port.

Using if condition for switch if (PINC&0X01) means PC0 is press than this pin is high as input.

In proteus search button for switch and earth is connected for doing earth after pressing otherwise pin is high for all time. We also use here pull-down register that’s 10k ohm in hardware also.

And led is connected on PA0 so PORTA=0b00000001 .
        

0-99 display on 7segment in atmega16/32

#include <avr/io.h>
#include<util/delay.h>
int arr[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
 void main()
{

 int i,j;
 DDRA=0xFF;
 DDRB=0xFF;
 while(1)
 {
  for(i=0;i<=1;i++)
  {
   PORTA=arr[i];

for(j=0;j<=9;j++)
  {
   PORTB=arr[j];
   _delay_ms(1000);

  }
  }
 }
 }

In this program when we are taking i loop 0-9 and j loop 0-9 then display 0-99 on segment and for loop is working.     

 

 

0-19 display on 7segment in atmega16/32

#include <avr/io.h>
#include<util/delay.h>
int arr[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};
 void main()
{

 int i,j;
 DDRA=0xFF;
 DDRB=0xFF;
 while(1)
 {
  for(i=0;i<=1;i++)
  {
   PORTA=arr[i];

for(j=0;j<=9;j++)
  {
   PORTB=arr[j];
   _delay_ms(1000);

  }
  }
 }
 }

In this program when we are taking i loop 0-1 and j loop 0-9 then display 0-19 on segment and for loop is working.     

 

 

interfacing of 7segment basic

#include <avr/io.h>
 void main()
{
  while (1)
{
    DDRA=0XFF;
{
    PORTA=0X3F;
}
}
}

 

there are two types of 7 segment :

1. Common anode

2. Common cathode

IN 7 segments we are using 7-segment common cathode and colour are own choice.

In this there are some pins:

A, B, C, D, E, F, G and last is dp.

This segment is display 0-9 no. of digits.

In hex form that can be written as:

0= 0x3F

1= 0X06

2 = 0X5B

3= 0X4F

4= 0X66

5= 0X6D

6= 0X7D

7= 0X07

8= 0X7F

9=0X6F

use this hex form and display any no.