Unipolar Stepper Motor Control From IR Remote Control Using PIC18F4550

Remote controlled stepper motor using PIC18F4550

 

This project shows how to control a 5V unipolar stepper motor from IR remote control uses NEC protocol with PIC18F4550 microcontroller. This controller controls the stepper motor speed and direction of rotation.
If you want to see how to drive the unipolar stepper motor using PIC18F4550 microcontroller read the following topic:
Interfacing unipolar stepper motor with PIC18F4550 microcontroller
And if you want to see how to decode IR remote control with NEC protocol see the following topic:
Extended NEC IR remote control decoder with PIC18F4550 microcontroller
To drive the unipolar stepper motor we need ULN2003 (ULN2004) Darlington transistor array or L293D motor driver as described in the previous topic.
The IR remote control used in this project is shown below:

Project circuit schematic is shown below.

 

PIC18F4550 microcontroller internal oscillator is used.
Remote controlled unipolar stepper motor using PIC18F4550 CCS C code:
External interrupt is used to read IR remote control signals.

// Remote controlled stepper motor using PIC18F4550 CCS C code
// http://ccspicc.blogspot.com/
// electronnote@gmail.com

#include <18F4550.h>
#fuses NOMCLR INTRC_IO
#use delay(clock = 8000000)
#use fast_io(B)
#use fast_io(D)

short Direction;
unsigned int8 step_number = 0, speed_delay = 2;
unsigned int32 remote_code;
#INT_TIMER1                                  // Timer1 interrupt ISR
void timer1_isr(void){
  remote_code = 0;
  clear_interrupt(INT_TIMER1);
  disable_interrupts(INT_TIMER1);
}
#INT_EXT                                     // External interrupt ISR
void ext_isr(void){
  unsigned int8 count = 0, i;
  unsigned int32 ir_code;
  // Check 9ms pulse (remote control sends logic high)
  while((input(PIN_B0) == 0) && (count < 200)){
    count++;
    delay_us(50);}
  if( (count > 199) || (count < 160))        // NEC protocol?
    return;                          
  count = 0;
  // Check 4.5ms space or repeated code
  while((input(PIN_B0)) && (count < 100)){
    count++;
    delay_us(50);}
  if( (count > 99) || (count < 30))          // NEC protocol?
    return;
  // Check repeated code
  if(count < 60){
    count = 0;
    while((input(PIN_B0) == 0) && (count < 14)){
      count++;
      delay_us(50);}
    if( (count > 13) || (count < 8))         // NEC protocol?
      return;
    if((remote_code == 0x40BF50AF) || (remote_code == 0x40BF906F))
    set_timer1(0);
  }
  // Read message (32 bits)
  for(i = 0; i < 32; i++){
    count = 0;
    while((input(PIN_B0) == 0) && (count < 14)){
      count++;
      delay_us(50);}
    if( (count > 13) || (count < 8))         // NEC protocol?
      return;                          
    count = 0;
    while((input(PIN_B0)) && (count < 40)){
      count++;
      delay_us(50);}
    if( (count > 39) || (count < 8))         // NEC protocol?
      return;                           
    if( count > 20)                          // If space width > 1ms
      bit_set(ir_code, (31 - i));            // Write 1 to bit (31 - i)
    else                                     // If space width < 1ms
      bit_clear(ir_code, (31 - i));          // Write 0 to bit (31 - i)
  }
  if((ir_code == 0x40BF50AF) || (ir_code == 0x40BF906F)){
    set_timer1(0);
    clear_interrupt(INT_TIMER1);
    enable_interrupts(INT_TIMER1);}
  if(ir_code == 0x40BFA05F){
    speed_delay++;
    if(speed_delay > 20) speed_delay = 20;
    return;}
  if(ir_code == 0x40BF609F){
    speed_delay--;
    if(speed_delay < 2) speed_delay = 2;
    return;}
  remote_code = ir_code; 
}
void stepper(int8 step){
  if(Direction == 0){
    switch(step){
      case 0:
        output_d(0b00000011);
        break;
      case 1:
        output_d(0b00000110);
        break;
      case 2:
        output_d(0b00001100);
        break;
      case 3:
        output_d(0b00001001);
        break;
    }
  }
  if(Direction == 1){
    switch(step){
      case 0:
        output_d(0b00001001);
        break;
      case 1:
        output_d(0b00001100);
        break;
      case 2:
        output_d(0b00000110);
        break;
      case 3:
        output_d(0b00000011);
        break;
    }
  }
}
void main(){
  setup_oscillator(OSC_8MHZ);                 // Set internal oscillator to 8MHz
  setup_adc_ports(NO_ANALOGS);                // Configure AN pins as digital
  set_tris_b(1);                           // Configure RB0 as digital input pin
  port_b_pullups(TRUE);                       // Enable PORTB internal pull-ups
  output_d(0);                                // PORTD initial state
  set_tris_d(0);                              // Configure PORTD pins as outputs
  setup_timer_1(T1_INTERNAL | T1_DIV_BY_4);   // Timer1 configuration
  enable_interrupts(GLOBAL);                  // Enable global interrupts
  enable_interrupts(INT_EXT_H2L);                 // Enable external interrupt
  while(TRUE){
    output_d(0);
    while(remote_code == 0x40BF40BF){
      Direction = 0;
      stepper(step_number);
      step_number++;
      if(step_number > 3) 
        step_number = 0;
      delay_ms(speed_delay);
    }
    while(remote_code == 0x40BF807F){
      Direction = 1;
      stepper(step_number);
      step_number++;
      if(step_number > 3) 
        step_number = 0;
      delay_ms(speed_delay);
    }
    while(remote_code == 0x40BF50AF){
      Direction = 0;
      stepper(step_number);
      step_number++;
      if(step_number > 3) 
        step_number = 0;
      delay_ms(speed_delay);
    }
    while(remote_code == 0x40BF906F){
      Direction = 1;
      stepper(step_number);
      step_number++;
      if(step_number > 3) 
        step_number = 0;
      delay_ms(speed_delay);
    }
  }
}

Remote controlled unipolar stepper motor using PIC18F4550 video: