Colony » Colony Scout » Colony Scout OS

#include <stdint.h>

#include <avr/io.h>

#include <avr/interrupt.h>

#include <util/delay.h>

#include "twi.h"

#include "bomi2c.h"

#define QUEUE_SIZE 64

uint16_t queue[QUEUE_SIZE];

int queue_idx;

char last_bit;

char count;

uint16_t data;

#define READ_BIT(pin, bit) (((pin) >> bit) & 1)

#define SET_BIT(pin, bit) ((pin) |= (1 << (bit)))

#define RESET_BIT(pin, bit) ((pin) &= ~(1 << (bit)))

static void send_bit(char bit);

static void slave_tx(void) {

  twi_transmit((uint8_t*)queue, queue_idx * sizeof(queue[0]));

  queue_idx = 0;

}

static void slave_rx(uint8_t *buf, int len) {

  if (len > 0) {

    switch (buf[0]) {

      case BOM_I2C_SEND:

        // TODO

        break;

    }

  }

}

static void bom_start(void) {

  data = 0;

  count = 0;

  last_bit = 1;

  // TODO disable interrupt

  // TODO start timer

}

static void bom_stop(void) {

  // TODO stop timer

  // TODO restart INT0

}

static void bom_init(void) {

  // setup INT0

  //EICRA |= _BV(ISC01) | _BV(ISC00);

  //EIMSK |= _BV(INT0);

  // setup timer 0

  //TCCR0B |= _BV(CS01);

  // setup output pin

  SET_BIT(DDRD, 5);

  //sei();

  bom_start();

}

ISR(TIMER0_COMPA_vect) {

  char this_bit = READ_BIT(PIND, PD2);

  if (this_bit == 0) {

    if (last_bit == 0) {

      bom_stop();

    }

  } else {

    data = data << 1 | (~last_bit & 1);

    count++;

  }

  last_bit = this_bit;

  if (count == 15) {

    if (queue_idx < QUEUE_SIZE) {

      queue[queue_idx] = data;

      queue_idx++;

    }

    bom_stop();

  }

}

static void send_data(uint16_t data) {

  for (int i = 14; i >= 0; i--) {

    send_bit((data >> i) & 1);

  }

  send_bit(0);

}

static void send_bit(char bit) {

  SET_BIT(PORTD, PD5);

  _delay_us(320);

  RESET_BIT(PORTD, PD5);

  if (bit) {

    _delay_us(1680);

  } else {

    _delay_us(680);

  }

}

int main() {

  bom_init();

  for (;;) {

    send_data(45243);

    _delay_ms(100);

  }

}

ISR(INT0_vect) {

  bom_start();

}