/*
 * Pajeci_stanice_2012.c
 * Processor: Atmel ATmega16
 * Created: 6.6.2012 23:15:40
 * Author: Luboš Fukan, Czech Republic
 */

#include <avr/io.h>
#include <util/delay.h>
#include <compat/deprecated.h>

#define LCD
#include "lcd_lib.h"
char text[8];

void max6675_select() {
    cbi(PORTB, 4);
    PORTA=0b11111110; //led diode indication instead of debugger :((
}

void max6675_deselect() {
    sbi(PORTB, 4);
    PORTA=0b01111111; //led diode indication instead of debugger :((
}

uint8_t send_spi(uint8_t spi_data)
{
  SPDR = spi_data;
  while (!(SPSR & (1<<SPIF)));
  return SPDR;
}

void max6675_read_temp()
{
    /* Enable SPI, Master, set clock rate fck/16 */
    SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR0);

    short value = 0;
    float temp = 0;

    uint8_t highByte=0;
    uint8_t lowByte=0;

    max6675_select();
    _delay_ms(1000);
    highByte = send_spi(0);
    lowByte = send_spi(0);
    max6675_deselect();

    if (lowByte & (1<<2)) {
        LCDGotoXY(0,0);
        sprintf(text,"TC NOT C");
        LCDstring(text,8);
        LCDGotoXY(0,1);
        sprintf(text,"ONNECTED");
        LCDstring(text,8);
    } else {
        value = (highByte << 5 | lowByte>>3);
        temp = (value*0.25);
        // Multiply the value by 0.25 to get temp in ˚C
        LCDGotoXY(0,0);
        sprintf(text,"TC TEMP:");
        LCDstring(text,8);
        LCDGotoXY(0,1);
        sprintf(text,"%0.8d", temp);
        LCDstring(text,8);
    }

}

int main(void)
{
    DDRA=0b11111111;

    LCDinit();
    LCDclr();

    LCDGotoXY(0,0);
    sprintf(text,"  MAX667");
    LCDstring(text,8);
    LCDGotoXY(0,1);
    sprintf(text,"5 TEST  ");
    LCDstring(text,8);

    while (1)
    {
        max6675_read_temp();
        _delay_ms(500);
    }
}