audio player using PIC18F4550 برمجة على الموسيقى

المكونات

• PIC18F4550 microcontroller
• SD card
• ASM1117 3.3 voltage regulator
• Audio amplifier (ex: PC speaker, LM386 ......)
• Speaker
• 8 MHz crystal oscillator
• 2 x 22pF ceramic capacitors
• 3 x 3.3K ohm resistor
• 3 x 2.2K ohm resistor
• 10K ohm resistor
• 1K ohm resistor
• 2 x 10uF polarized capacitor
• 100nF ceramic capacitor
• 5V Power source
• Breadboard
• Jumper wires

كود المستعمل 

// SD Card module connections
#define   SDCARD_SPI_HW
#define   SDCARD_PIN_SELECT  PIN_D2
// End SD card module connections

#include <18F4550.h>
#fuses NOMCLR HSPLL PLL2 CPUDIV1
#use delay(clock = 48MHz)
#use fast_io(D)
#include <FAT_Lib.c>

const int8 *wav = "audio.wav";
int1 ok = 0;
int8 i, j, data[32], channel_count;

void play(){
  file_pointer += 44;                        // Skip wave file header (44 bytes)
  sdcard_read_byte(address_pointer + 22, &channel_count);       // Read number of channels
  while(fat_read_data(32, data) == 0){
    for(i = 0; i < 32; i++){
      set_timer1(0);
      j = data[i];
      set_pwm1_duty((int16)j);                   // Update PWM1 duty cycle
      if(channel_count == 2){                    // If 2-channel wave file (stereo)
        i++;                                     // increment i
        j = data[i];
        set_pwm2_duty((int16)j);                 // Update PWM2 duty cycle
      }
      while(get_timer1() < 650);                 // Wait some time (about 62.5us) to update the duty cycles
    }
  }
}
void main(){
  delay_ms(2000);
  setup_ccp1(CCP_PWM);                           // Configure CCP1 as a PWM
  setup_ccp2(CCP_PWM);                           // Configure CCP2 as a PWM
  set_pwm1_duty(0);                              // set PWM1 duty cycle to 0
  set_pwm2_duty(0);                              // set PWM2 duty cycle to 0
  setup_timer_2(T2_DIV_BY_1, 63, 1);             // Set PWM frequency to maximum with 8-bit resolution
  setup_timer_1( T1_INTERNAL | T1_DIV_BY_1 );
  ok |= sdcard_init();                           // Initialize the SD card module
  ok |= fat_init();                              // Initialize FAT library
  ok |= fat_open_file(wav);                      // Open the wave file
  if(ok == 0){
    play();
  }
  set_pwm1_duty(0);                              // set PWM1 duty cycle to 0
  set_pwm2_duty(0);                              // set PWM2 duty cycle to 0
}   // End