Microcontroller Pin Configuration Is Shown

Published Date: 02 Nov 2017

Abstract

This repot is about pic16f84a microcontroller programming that how we write a program and how to burn it. In this report there is little introduction about controller and most of code are described. This report is on subject digital electronics designs. There are different tasks which we have to complete by writing their coding and check the program by burn it into microcontroller.

We use pic16f84a microcontroller for programming in lab session of digital electronics fundamentals and MPLAB IDE v8.33 and HI-TECH compiler software for our lab.

Pic16f84a is 18 pins microcontroller pin configuration is shown. Vss is used to supply 5v and Vdd is used as ground. There are four interrupts External RB0/INT pin TMR0 timer overflow PORTB<7:4> interrupt-on-change Data EEPROM write complete. RB6, RB7, Vss, Vdd and MCLR used to burn the programe.

I/O ports:

RA0 to RA4 pins of porta and RB0 to RB7 pins of portb are used as input output in microcontroller.

In lab1 our first task is to use microcontroller RB0 to RB4 pins as output which are connected to leds and RA0 to RA4 pins as input through programming in MPLAB. When we write full program then compile it to check the errors download it into microcontroller.

First task code:

#include<htc.h> // header file

#define LED1 PORTBbits.RB0 // define portb pins as LED# so no need to write address of complete pin in main program

#define LED2 PORTBbits.RB1

#define LED3 PORTBbits.RB2

#define LED4 PORTBbits.RB3

#define LED5 PORTBbits.RB4

void delay (void); // delay function but no need in this task

void main(void) //main function

{

TRISA=0xFF; //define porta as input

TRISB=0x00; //define portb as output

LED1=0; //all portb initial value is 0

LED2=0;

LED3=0;

LED4=0;

LED5=0;

PORTA=PORTB;

PORTA=0x00; //input is initially zero

delay();

while(1) //loop when true loop will run infinitely

{

if(PORTAbits.RA0==1) //to turn on led1 give PORTA value ‘1’ means turn on switch which is connected to RA0 pin in if statement means when RA0 is when go into if body and do that else do what is in else body

{

LED1=1;

}

else LED1=0;

if(PORTAbits.RA1==1) //to turn on led2

{LED2=1;}

else LED2=0;

if(PORTAbits.RA2==1) //to turn on led3

{LED3=1;}

else LED3=0;

if(PORTAbits.RA3==1) //led4 turn on

{LED4=1;}

else LED4=0;

if(PORTAbits.RA4==1) //led5 turn on

{LED5=1;}

else LED5=0;

}

}

void delay (void) //delay function

{

int n; //define integer

for (n=0;n<50;n++); //for loop which run unless n=50 then go back to program where delay is call

}

Task two:

In task two we have to transfer data from Port B to Port A.

Task two codes:

#include<htc.h>

#define LED1 PORTAbits.RA0 //in this task we define Porta pins as LED# because we want to show output on porta

#define LED2 PORTAbits.RA1

#define LED3 PORTAbits.RA2

#define LED4 PORTAbits.RA3

#define LED5 PORTAbits.RA4

void delay (void);

void main(void)

{

TRISA=0x00; //initialize porta as output

TRISB=0xFF; //initialize portb as input

LED1=0; //all leds initial value is set to 0

LED2=0;

LED3=0;

LED4=0;

LED5=0;

while(1)

{

if(PORTBbits.RB0==1) //portb use as switch write statement in if function

{ LED1=1; //turn on led1 on RA0

}

else LED1=0;

if(PORTBbits.RB1==1)

{

LED2=1;

}

else LED2=0;

if(PORTBbits.RB2==1)

{ LED3=1;

}

else LED3=0;

if(PORTBbits.RB3==1)

{LED4=1;}

else LED4=0;

if(PORTBbits.RB4==1)

{

LED5=1;

}

else LED5=0;}

}

Task three:

In task three we have to turn on light on portb with delay of 1 second for this task we modify previous program and burn it into microcontroller.

Task three codes:

#include<htc.h>

#define LED1 PORTBbits.RB0 //define portb pin as LED#

#define LED2 PORTBbits.RB1

#define LED3 PORTBbits.RB2

#define LED4 PORTBbits.RB3

#define LED5 PORTBbits.RB4

void delay (int d);

void main(void)

{

TRISB=0x00; //initialize as output

LED1=0;

LED2=0;

LED3=0;

LED4=0;

LED5=0;

while(1) //while loop run endlessly

{

LED1=1; //turn on led1

delay(66); //delay of 1 second

LED1=0; //turn off led 1

LED2=1; //turn on led2

delay(66); //delay of 1 second

LED2=0; //turn off led2

LED3=1;

delay(66);

LED3=0;

LED4=1;

delay(66);

LED4=0;

LED5=1;

delay(66);

LED5=0;

}

}

int d;

void delay (int d) //delay function int d is integer value which we write in delay fuction

{

int b;

int n;

for (n=0;n<d;n++) //for loop run unless value is less then integer d value

{

for (b=0;b<1000;b++);

}}

Task four:

Write a program on traffic light signal

Sequence is shown in picture

Four task codes:

#include<htc.h>

#define GREEN1 PORTBbits.RB7 //define portb pin 7 as green1

#define AMBER1 PORTBbits.RB6 //define portb pin 6 as amber1

#define RED1 PORTBbits.RB5 //define portb pin 5 as red1

#define GREEN2 PORTBbits.RB4 //define portb pin 4 as green2

#define AMBER2 PORTBbits.RB3 //define portb pin 3 as amber2

#define RED2 PORTBbits.RB2 //define portb pin 2 as red2

void delay (int d); //delay function

void main(void) //main function

{

TRISB=0x00; //initialize trisb as output value written in hexadecimal

GREEN1=0; //initial valuse of all leds are set to 0

AMBER1=0;

RED1=0;

GREEN2=0;

AMBER2=0;

RED2=0;

while(1) //while loop

{

PORTB=0b00110000; //green2 and red1 are on

delay(262); //delay of 4 seconds

PORTB=0b00101000;//red1 amber2 are on

delay(131); //delay of 2 seconds

PORTB=0b00100100;//red1 and red 2 are on

delay(132);

PORTB=0b00110100;//red1,red2 and amber1 are on

delay(132);

PORTB=0b10000100;//red2 and green1 are on

delay(262);

PORTB=0b01000100;//red2 and amber1 are on

delay(132);

PORTB=0b00100100;//red2 and red1 are on

delay(132);

PORTB=0b00101100;//red2,red1 and amber2 are on

delay(132);

}

}

int d;

void delay (int d) //delay function

{

int b;

int n;

for (n=0;n<d;n++)

{

for (b=0;b<1000;b++); //for loop

}}

Task five:

We modify previous program by using switches RA0 and RA1 on the development board so that the lights remain in the r1 g2 state until the RA0 switch is pressed and remains in the g1 r2 state until the RA1 switch is pressed.

Task five codes:

#include<htc.h>

#define GREEN1 PORTBbits.RB7

#define AMBER1 PORTBbits.RB6

#define RED1 PORTBbits.RB5

#define GREEN2 PORTBbits.RB4

#define AMBER2 PORTBbits.RB3

#define RED2 PORTBbits.RB2

#define S1 PORTBbits.RA1 //define

#define S2 PORTBbits.RA0

void delay (int d);

void main(void)

{

TRISB=0b00000000; //portb as output

TRISA=0x03; //initialize porta two pin RA1 and RA0 as input

PORTB=0x00;

GREEN1=0; //initial value is 0

AMBER1=0;

RED1=0;

GREEN2=0;

AMBER2=0;

RED2=0;

while(1)

{

PORTB=0b00110000; //green1 and red2 are on

delay(262); //delay

while(S1==0); //when sensor 1 is zero remain in this state

PORTB=0b00101000;//red1 amber2 are on

delay(131);

PORTB=0b00100100;//red1 and red 2 are on

delay(132);

PORTB=0b00110100;//red1,red2 and amber1 are on

delay(132);

PORTB=0b10000100;//red2 and green1 are on

delay(262);

while(S2==0); //remain in this state until s2 is equal to 1

PORTB=0b01000100;//red2 and amber1 are on

delay(132);

PORTB=0b00100100;//red2 and red1 are on

delay(132);

PORTB=0b00101100;//red2,red1 and amber2 are on

delay(132);

}

}

int d;

void delay (int d)

{

int b;

int n;

for (n=0;n<d;n++)

{

for (b=0;b<1000;b++);

}

}

Lab 2:

In second lab our first task is to run motor clockwise and anticlockwise and stop. We use RA4 and RA3 to determine it’s these states. When the value on these pins are same then motor will be stop and run in clock wise direction when value on RA3 is one and RA4 is zero when these values are reverse then motor will run in anti-clockwise direction.

We use IR sensor to count its rotations. It is connected to RA1 pin of microcontroller. The microcontroller can monitor the rotation of the motor by detecting the rising or falling edges on this input pin. The steps which we follow in this exercise are Start motor

Detect three falling edges on pin RA1

Stop motor

Wait for about half a second

Start motor in reverse direction

Detect three falling edges on pin RA1

Stop motor

Wait for about half a second

Task 1 code:

#include <htc.h>

#define RA3 PORTAbits.RA3

#define RA4 PORTAbits.RA4

void delay(void); //delay function

void edge(void); //edge function to count rising or falling edge

void main( void)

{

// initialise Port A and Port B

TRISA = 0b00011; ; /* set tris B register */

TRISB = 0x00; ; /* tris B all o/p */

PORTA = 0b00000 ; /* set Port A register to 0 */

INTCON=0X00; //initial value of intcon register is set to zero

int b;

for(b=0;b<10;b++) //for loop which will run 10 times

{

PORTB=b+1; //increment in port b value till to run 10 times for loop

RA3=0 ; //run anticlock wise

RA4=1;

edge();

RA3=0; //stop

RA4=0;

delay(); //delay about second

RA3=1; //run clockwise direction

RA4=0;

edge();

RA3=0; //stop

RA4=0;

delay();

}

while(1); //after running for loop 10 time it will stuck here

} // end of main

void edge(void) //edge function which will count three edges

{

int a;

for(a=0;a<3;a++)

{

while(PORTAbits.RA1==1);

while(PORTAbits.RA1==0);

}}

void delay(void) //delay function using inner interrupt of microcontroller to generate delay of one second

{

TMR0=0x0c; //timer0 initial value

OPTION_REG=0x87; //set option register value and use prescalar

while(INTCONbits.T0IF==0); //program will remain in this while loop until flag is set high

INTCONbits.T0IF=0; //set flag to zero

}

Task two of lab2:

#include <htc.h>

#define RA3 PORTAbits.RA3 //define porta pins

#define RA4 PORTAbits.RA4

#define RB0 PORTBbits.RB0 //define port b pins

#define RB1PORTBbits.RB1

#define RB2 PORTBbits.RB2

#define RB3 PORTBbits.RB3

#define RB4 PORTBbits.RB4

#define RB5 PORTBbits.RB5

#define RB6 PORTBbits.RB6

#define RB7 PORTBbits.RB7

int a;

a=0;

void edge(void); //edge function

void main( void) //delay function

{

TRISA = 0b00011; //initialize port a two pins as input and other as output

TRISB = 0x00; //initialize portb as output

TMR0=0; //set timer0 value to zero

INTCONbits.T0IE=1; //enable intocon register timer0 overflow interrupt

INTCONbits.GIE=1; //enable global interrupt

OPTION_REG=0b11001000; //set RBPU Interrupt Edge Select bit to rising edge and not use prescalar

PORTB=0; //set initial value of portb to zero

while(1) //loop will run endlessly

{

RA3=0 ; //run fan in one direction

RA4=1;

edge(); //edge function which will run to three edges

TMR0=254; //interrupt of timer 0 overflow

RA3=0; //stop motor

RA4=0;

RA3=1; run motor in other direction

RA4=0;

edge(); //edge function

TMR0=254;

RA3=0;

RA4=0;

while(1);

}} // end of main

void edge(void) //edge function

{int a;

for(a=0;a<3;a++)

{

while(PORTAbits.RA1==1);

while(PORTAbits.RA1==0);

}

}

void interrupt ISR() //interrupt function which is use to turn on off leds in sequence

{

INTCONbits.GIE=0; //set global interrupt to zero

while(a<7) //this loop will run 7 times

{

if( INTCONbits.T0IF == 1&&a==0) //if statement when timer0 flag is high and int a is zero then go into if body

{

RB0=!RB0; //toggle led on RB0

}

if( INTCONbits.T0IF == 1&&a==1) //second if to toggle other led

{

RB0=!RB0;

RB1=!RB1;}

if( INTCONbits.T0IF == 1&&a==2)

{

RB1=!RB1;

RB2=!RB2;

}

if( INTCONbits.T0IF == 1&&a==3)

{

RB2=!RB2;

RB3=!RB3;}

if( INTCONbits.T0IF == 1&&a==4)

{

RB3=!RB3;

RB4=!RB4;

}

if( INTCONbits.T0IF == 1&&a==5)

{

RB4=!RB4

RB5=!RB5;

}

if( INTCONbits.T0IF == 1&&a==6)

{

RB5=!RB5;

RB6=!RB6;

}

if( INTCONbits.T0IF == 1&&a==7)

{

RB6=!RB6;

RB7=!RB7;

}

break;

}

if(a==7) //when loop complete 7 cycle then go to if body and set portb to zero

{

PORTB=0;

}

INTCONbits.T0IF = 0; // reset INT0 interrupt flag

INTCONbits.GIE=1; //enable global interruput

}

Task three of lab2 multiple interrupts:

In this lab we use multiple interrupts to use blinking of led’s in one direction then to reverse direction

#include <htc.h>

#define RA3 PORTAbits.RA3 //define porta pins

#define RA4 PORTAbits.RA4

#define RB0 PORTBbits.RB0 //define portb pins

#define RB1PORTBbits.RB1

#define RB2 PORTBbits.RB2

#define RB3 PORTBbits.RB3

#define RB4 PORTBbits.RB4

#define RB5 PORTBbits.RB5

#define RB6 PORTBbits.RB6

#define RB7 PORTBbits.RB7

void delay(void); //delay function

int dir=0; //int direction

void edge(void); //edge funciton

void main( void)

{

TRISA = 0b00011; //initialize porta pins

TRISB = 0b00000001; //initialize portb pins as output except RB0 which is used as external interrupt

PORTA = 0b00000 ; /* set Port A register to 0 */

TMR0=0; //initial value of timer0 is set to 0

INTCON=0b11111000; //set intcon register enable these interrupt Global Interrupt Enable bit EE Write Complete Interrupt Enable bit TMR0 Overflow Interrupt Enable bit RB0/INT External Interrupt Enable bit and RB Port Change Interrupt Enable bit

OPTION_REG=0b11001000;

PORTB=0; //set portb to zero

while(1) //loop will run endlessly

{

RA3=0 ; //MOVE FORWARD

RA4=1;

edge(); //THREE RISING EDGE

TMR0=254;

RA3=0; //STOP

RA4=0;

RA3=1; //BACKWARD

RA4=0;

edge();

TMR0=254; //timer0 interrupt

RA3=0; //stop

RA4=0;

while(1);

}} // end of main

void edge(void) //edge function

{

int a;

for(a=0;a<3;a++)

{

while(PORTAbits.RA1==1);

while(PORTAbits.RA1==0);

}}

void delay (void) //delay function

{

int n;

for (n=0;n< 5;n++);

}

void interrupt ISR() //interrupt

{

INTCONbits.GIE=0; //disable all other interruputs

if(dir==0) //if statement when int dir is 0 then turn on leds on one direction

{

RB1=1; //turn on led connected to RB1

delay(); //delay function

RB1=0;

RB2=1; //turn on other led

delay();

RB2=0;

RB3=1;

delay();

RB3=0;

RB4=1;

delay();

RB4=0;

RB5=1;

delay();

RB5=0;

RB6=1;

delay();

RB6=0;

RB7=1;

delay();

}

else //it is used to turn on led’s in reverse direction

{

RB7=1;

delay();

RB7=0;

RB6=1;

delay();

RB6=0;

RB5=1;

delay();

RB5=0;

RB4=1;

delay();

RB4=0;

RB3=1;

delay();

RB3=0;

RB2=1;

delay();

RB2=0;

RB1=1;

delay();

}

dir=!dir; //reverse the direction of leds

INTCON=0b11111000;}