AES: Activity 2. Create a moving dot: Activity 2

The purpose of this activity is to interrupt the main program. In the main program 8 LEDs flash. When an interrupt occurs from INT2, the LEDs create a moving dot.

(35 minutes)

Step 1. The circuit is drawn in the Proteus Design Suite.

Step 2. The program in C language is written.

Write in CCS C Compiler the program in C language

#include <main.h> // the file main.h with the

// initial settings is included

// This file must be placed in the same

// folder with the project

// Also the 18F4550.h file must exist

// in the same folder with the project

#byte PORTD =0xF83 // We attribute to the memory position 0xF83

// the name PORTD

// This means that we define a 8 bit

// variable whose value will be stored

// to the memory position F83h

// The memory position F83h is the PORTD

// data register

void init(void);

void ext_int2(void);

void main(){

init(); //initialization routine

while(TRUE){ //flash 8 LEDs

PORTD=0b11111111;

delay_ms(100);

PORTD=0b00000000;

delay_ms(100);

}

//initialization routine

void init(){

set_tris_d(0x00); //PORTD is defined as output

PORTD = 0b00000000; //The PORTD data register is given the value 0

ext_int_edge(2, H_TO_L); //Activation of the interrupt from RB2

//during the transition from 1 to 0 (falling edge)

enable_interrupts(GLOBAL); //Enable global interrupts

enable_interrupts(INT_EXT2); //Enable external interrupt by RB2

}

//external interrupt by RB2

#INT_EXT2

void ext_int2() { //moving dot

PORTD=0b00000000; delay_ms(200);

PORTD=0b10000000; delay_ms(200);

PORTD=0b01000000; delay_ms(200);

PORTD=0b00100000; delay_ms(200);

PORTD=0b00010000; delay_ms(200);

PORTD=0b00001000; delay_ms(200);

PORTD=0b00000100; delay_ms(200);

PORTD=0b00000010; delay_ms(200);

PORTD=0b00000001; delay_ms(200);