Subversion Repositories group.electronics

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

#include "config.h"
#include "uart.h"

#ifndef NULL
#define NULL    ((void *)0)
#endif


/* ------------------------------------------------------------------------- */

#define UART_BAUD_RATE  9600

volatile uint8_t tmr0_ovf = 0;
volatile uint32_t systime = 0;

volatile uint16_t sendtime = 1000;


int main(void) {


  /*
  DDR : 1 = Output, 0 = Input
  PORT: 1 = Pullup for Input, otherwise set output
  PIN : Read input pin
  */

  /*
        PB0     - 
        PB1     - 
        PB2     - 
        PB3     - 
        PB4     - 
        PB5     - 
        PB6     - 
        PB7     - 
  */
  DDRB          = 0B11111111;
  PORTB         = 0B00000000;

  /*
        PC0     - 
        PC1     - 
        PC2     - 
        PC3     - 
        PC4     - 
        PC5     - 
  */
  DDRC          = 0B11111111;
  PORTC         = 0B00000000;

  /*
        PD0     - 
        PD1     - 
        PD2     - 
        PD3     - 
        PD4     - 
        PD5     - Input PcInt           - * I/O Interrupt PCINT21
        PD6     - Output                - * Status LED
        PD7     - Input, Pullup         - * Button
  */
  DDRD          = 0B01011111;
  PORTD         = 0B10000000;

    TIMSK0 = (1<<TOIE0);                    // Enable timer overflow
    TCNT0 = 0x00;                           // Set Timer0 initial value to 0
    TCCR0B = (1<< CS00) ;                   // /1 prescaler

    
    
  
  uart_init( UART_BAUD_SELECT(UART_BAUD_RATE,F_CPU) );

  
    wdt_enable(WDTO_1S);                // Watchdog for 1 sec
    sei();                              // Enable interrupts

    sbi(PIND, PD6);
    _delay_ms(500);
    cbi(PIND, PD6);
    
  char buffer[7];

    for(;;){
        wdt_reset();
        
        if (rbi(PIND, PD7))
           cbi(PORTD, PD6);
        else
           sbi(PORTD, PD6);
        

        
        if (!sendtime) {
          ltoa(systime, buffer, 10);
          uart_puts(buffer);
          uart_puts("\r\n");
          sendtime=1000;
          xbi(PORTD, PD6);
        }
        _delay_ms(1);
        
    }

    return 0;
}


ISR(TIMER0_OVF_vect) {
        tmr0_ovf++;

        // Clk/1 TCCR0B = (1<< CS00);
        //20.0Mhz, 1ms = 78ovf
        //16.5Mhz, 1ms = 64ovf
        //16.0Mhz, 1ms = 62ovf
        //12.0Mhz, 1ms = 46ovf

        if (tmr0_ovf>=64) {
                systime++;
                tmr0_ovf = 0;
                if (sendtime)
                  sendtime--;
        }
}