ATtiny13 UART Komunikasi Serial Arduino

Setelah rangkaian selesai, silahkan buka serial monitor pada arduino, lalu lakukan pengujian kode program.

#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

volatile uint8_t uart;
uint8_t temp;
volatile uint8_t count;
volatile uint8_t start;
volatile uint8_t c;
volatile uint8_t uart_data;
volatile uint8_t Rece_bit;
volatile uint8_t rec;
volatile uint8_t usart_r;
volatile uint8_t baudSpeed;

ISR(INT0_vect) {
  rec = 1;// Interrupt is purely to determine the start bit when receiving,
  // rarely used, you can hang something else here
}

ISR(TIM0_COMPA_vect) {
  TIMSK0 = 0x00;
  TCCR0B = 0x00; // Single Timer, used to form a clear gap
  OCR0A = 0;     // between bits, both when receiving and when transmitting
  c = 1;
  TCNT0 = 0;
  TIMSK0 = 0x04;
  TCCR0B = 0x02;
  // The value "reset on match" is loaded each time from the variable
  OCR0A = baudSpeed;    // You can quickly change the UART speeds
  Rece_bit = 1;
}

int send (uint8_t data)<
/span> {
  if (count >= 8) {
    PORTB |= (1 << 4); start = 0; temp = 0; c = 0; count = 0;
    TIMSK0 = 0; TCCR0B = 0; OCR0A = 0; goto nah;
  }

  if (c == 1) {
    if (start == 0) {
      temp = 0x80; start = 1;
      count--; goto razvet;
    }
    temp = data;
    temp = temp >> count;
    temp = temp << 7;
razvet:
    switch (temp) {
      case 0x80 : PORTB &= ~(1 << 4);  break;
      case 0x00 : PORTB |= (1 << 4);   break;
    }
    count++; c = 0;
  }
nah:;
}

void mySerial_print(char *text) {
  while (*text) {
    UART_trans(*text++);
  }
}

void mySerial_println(char *text) {
  while (*text) {
    UART_trans(*text++);
  }
  UART_trans('n');
}

void itoa(uint16_t n, char s[]) {
  uint8_t i = 0;
  do {
    s[i++] = n % 10 + '0';
  }
  while ((n /= 10) > 
0);
  s[i] = '';
  // Reversing
  uint8_t j;
  char c;
  for (i = 0, j = strlen(s) - 1; i < j; i++, j--) {
    c = s[i];
    s[i] = s[j];
    s[j] = c;
  }
}

void send_num(char *text, uint16_t n) {
  char s[6];
  itoa((uint16_t)n, s);
  mySerial_print(text);
  mySerial_print(s);
}

int UART_trans(uint8_t data) {
  uint8_t f;
  data = ~data;
  baudSpeed = 123;
  TIMSK0 = 0x04;
  TCCR0B = 0x02;
  for (f = 0; f < 10; f++) {
    while (c == 0);
    send(data);
  }
  start = 0; temp = 0; c = 0; count = 0;
  TIMSK0 = 0; TCCR0B = 0; OCR0A = 0;
  baudSpeed = 0;
}

int UART_receiv(void) {
  uint8_t a;
  usart_r = 0;

  MCUCR = 0x02; // INT0 Interrupt
  GIMSK = 0x40; // INT0 Interrupt

  while (rec == 0); // Wait until the start bit happens
  MCUCR = 0; // INT0 Interrupt
  GIMSK = 0; // INT0 Interrupt
  baudSpeed = 123;
  TIMSK0 = 0x04;
  TCCR0B = 0x02;
  rec = 0;
  TCNT0 = 0xDC;
  for (a = 0; a < 9; a++) {
    while (Rece_bit == 0);

    if (bit_is_set(PINB, 1)) {
      usart_r |= (1 << 7);
    } else {
      usart_r &= ~(1 << 7);
    }
    usart_r = usart_r >> 1;
    Rece_bit = 0;
  }
}

int main(void)
{
  DDRB &= ~(1 << 1); // set to RX (INPUT)
  DDRB |= (1 << 4);  // set to TX (OUTPUT)

  asm("sei");
  while (1)
  {
    UART_receiv(); // Receive a byte first
    _delay_ms(10);  // Pause for clarity
    UART_trans(usart_r);  // Send back to serial
    //mySerial_println("123");
  }
}