AVR I2C TC74

[Boldak Boldak]

Dobry podvecer,
po celodennim boji s I2C to vzdavam a prosim zdejsi profiky o pomoc.
Mam ATtiny 2313 a k tomu pripojeny teplotni senzor TC74, ktery
komunikuje pomoci I2C. SCL je pripojeno na PB7 a SDA je na PDB5.
Oba vodice jsou pres odpory 10k pripojeny na Vdd.

Otazecka pro zacatek, kdyz prijimam ACK pripadne byte z TC74,
musi byt SDA nastaven jako vstupni myslim tim DDRB &= ~(1<<sda)?
Nebo prikaz (PINB,sda) precte skutecnou hodnotu na pinu..??

Diky za kazde nakopnuti..

Zde posilam kod k nahlednuti.

PS: komentaru si zatim nevsimejte.. :)

#include <stdint.h>
#include <avr/io.h>
#include <avr/iotn2313.h>
#include <avr/interrupt.h>

#define F_CPU 11059200
#define scl PB7
#define led PB6
#define sda PB5

#include <util/delay.h>

void I2CInit(){

  PORTB |= (1<<sda)|(1<<scl); //sda=1, scl=1
  _delay_us(10); //wait 5us
}

void I2CStart(){

  PORTB |= (1<<scl); //scl=1
  _delay_us(10); //wait 5us
  PORTB &= ~(1<<sda); //sda=0
  _delay_us(10); //wait 5us
  PORTB &= ~(1<<scl); //scl=0
  _delay_us(2);
}

void I2CSend(unsigned char Data){
  unsigned char i;

  for(i=0;i<8;i++){
    PORTB &= ~(1<<scl); //scl=0
    _delay_us(10); //wait 5us

    if((Data&0x80)==0){
      PORTB &= ~(1<<sda); //sda = 0;
      _delay_us(2); //wait 2us
    }
    else {
      PORTB |= (1<<sda); //sda = 1;
      _delay_us(2); //wait 2us
    }

    PORTB |= (1<<scl); //scl = 1;
    _delay_us(10); //wait 5us

    Data<<=1; //posune MSB doleva, prvni se vysila MSB
  }

    PORTB &= ~(1<<scl); //scl = 0;
    PORTB |= (1<<sda); //sda = 1;
    _delay_us(2); //wait 1us
}

unsigned char I2CRead(){
  unsigned char i, data=0;

  for(i=0;i<8;i++){
    _delay_us(2);
    PORTB &= ~(1<<scl); //scl = 0
    _delay_us(10);
    PORTB |= (1<<scl); //scl = 1
    _delay_us(10);
    if(PINB,sda){
      data |= 1;
    }
    data<<=1;
  }
        PORTB &= ~(1<<scl); //scl = 0
PORTB |= (1<<sda); //sda = 1
        return (data);
}

void I2CAck(){
  PORTB &= ~(1<<sda); //sda = 0
  _delay_us(10); //ceka 10us
  PORTB |= (1<<scl); //scl = 1
  _delay_us(10); //ceka 10us
  PORTB &= ~(1<<scl); //scl = 0

  _delay_us(2); //ceka 2us
  PORTB |= (1<<sda); //sda = 1
}

void I2CNack(){
  PORTB |= (1<<sda); //sda = 1
  _delay_us(10);
  PORTB |= (1<<scl); //scl = 1
  _delay_us(10);
  PORTB &= ~(1<<scl); //scl = 0
}

/*
void blik (void) {
  unsigned char i;
  for (i=0;i<1;i++) {
    PORTB |= (1<<led);
    _delay_ms(100);
    PORTB &= ~(1<<led);
    _delay_ms(100);
  }
}
*/

/*
void svit (void) {
  PORTB |= (1<<led);
  _delay_ms(500);
}
*/

int main (void)
{
  unsigned char aa;
  int sto, deset, jedna, pom;

  cli(); //zakate preruseni

  DDRB |= (1<<sda)|(1<<scl)|(1<<led); //nastavi sda a scl jako vystup
  PORTB &= ~(1<<led);

  DDRD |= 0xFF; //nastavi led jako vystup
  PORTD |= 0xFF; //led zhasne

  I2CInit(); //init I2C

  I2CStart(); //start

  I2CSend(0x91); //vysle addressu TC74 0b10010001, posledni bit0 signalizuje
READ

  I2CAck(); //ack ???

  aa=I2CRead();

 // I2CNack();

  pom = aa;
  pom /= 100;
  sto = pom; //sto = ulozene stovky

  pom = 136;
  pom -= 100;
  pom /= 10;
  deset = pom; //deset = desitky

  pom = aa;
  pom -= 100;
  pom -= (deset*10);
  jedna = pom; //jedna = jednotky

  //deset = 5;

if (deset == 0) {
  PORTD = 0b10000001; //0
  _delay_ms(50);
  }
  else if (deset == 1) {
    PORTD = 0b1100111; //1
    _delay_ms(50); //ceka 50ms
  }
  else if (deset == 2) {
    PORTD = 0b10010010; //2
    _delay_ms(50); //ceka 50ms
  }
  else if (deset == 3) {
    PORTD = 0b11000010; //3
    _delay_ms(50); //ceka 50ms
  }
  else if (deset == 4) {
    PORTD = 0b11100100; //4
    _delay_ms(50); //ceka 50ms
  }
  else if (deset == 5) {
    PORTD = 0b11001000; //5
    _delay_ms(50); //ceka 50ms
  }
  else if (deset == 6) {
    PORTD = 0b10001000; //6
    _delay_ms(50); //ceka 50ms
  }
  else if (deset == 7) {
    PORTD = 0b11100011; //7
    _delay_ms(50); //ceka 50ms
  }
  else if (deset == 8) {
    PORTD = 0b10000000; //8
    _delay_ms(50); //ceka 50ms
  }
  else {
    PORTD = 0b11000000; //9
    _delay_ms(50); //ceka 50ms
  }

return(0);
}
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