I2C, Programm "crashed" beim Sende Versuch

[Julius (Gast)]

Hi,


dies ist mein zweiter Versuch mit I2C, diesmal das Auslesen einer RTC 
(DS1307).
Sobald die Zeile:

i2c_start_wait(rtc_clock+I2C_WRITE);

aktiv ist stellt der Chip das LED blinken ein.
Die LED's blinken bei jedem Durchlauf der While Schleife einmal mehr als 
beim letzten Durchlauf - Ich hoffe das ist eine sichere Methode um 
festzustellen das der Chip nicht neu gestartet ist.

Hat jemand eine Idee warum der Code mit der oben genannten Zeile hängt?

#include <avr/io.h>
#include <util/delay.h>
#include <i2cmaster.h> 


#define BAUD 9600
#define MYUBRR ((uint16_t) ((F_CPU / ((BAUD) * 16.0)) + .5) - 1)
#define LED1 PD6
#define LED2 PD7


// contains what the bluetooth module received
uint8_t data;

void USART_Init(unsigned int ubrr) {
    // set baud rate
    UBRRH = (unsigned char)(ubrr>>8);
    UBRRL = (unsigned char)(ubrr);
    // enable receiver, transmitter and interrupts for rx/tx
    UCSRB = (1<<RXEN) | (1<<TXEN) | (1<<RXCIE) | (1<< TXCIE);
}



void USART_transmit(char c) {
    while ( !(UCSRA & (1<<UDRE)) ) {}
    UDR = c;
}



void transmit_char(char c) {
    USART_transmit(c);
    USART_transmit('\r');
    USART_transmit('\n');
}



void send_string(char s[]) {
    int i =0;

    while (s[i] != 0x00) {
        USART_transmit(s[i]);
        i++;
    }
    USART_transmit('\r');
    USART_transmit('\n');

}


void flash_leds(uint8_t count) {
    for (int n=1; n<=count; n++) {
        PORTD |= (1 << LED1); // Turn on LED1
        PORTD |= (1 << LED2); // Turn on LED2
        _delay_ms(200);
        PORTD &= ~(1 << LED1); // Turn off LED1
        PORTD &= ~(1 << LED2); // Turn off LED2
        _delay_ms(200);
    }
}

/*
0xD0 = 1   1   0   1   0   0   0   0 = write
0xD1 = 1   1   0   1   0   0   0   1 = read

the first 6 bits contain the device id, and the last one tells the device if we want to read from it
or write to it
*/

// adress of the rtc clock device/chip
#define rtc_clock 0xD0



/* example: http://exploreembedded.com/wiki/Real_Time_Clock%28DS1307%29_with_AVR
void RTC_Init(void)
{
    I2C_Init();                             // Initialize the I2c module.
    I2C_Start();                            // Start I2C communication
 
    I2C_Write(C_Ds1307WriteMode_U8);        // Connect to DS1307 by sending its ID on I2c Bus
    I2C_Write(C_Ds1307ControlRegAddress_U8);// Select the Ds1307 ControlRegister to configure Ds1307
 
    I2C_Write(0x00);                        // Write 0x00 to Control register to disable SQW-Out
 
    I2C_Stop();                             // Stop I2C communication after initializing DS1307
}*/


// my init, adapted from the above
void init_i2c(void) {
    // initialize, taken from peter fleurys i2c example (he wrote the i2c code)
    i2c_init();
    // connect to the device and tell it that we want to write to it
    
    i2c_start_wait(rtc_clock+I2C_WRITE);
    // this is from rtc.h from the exploreembeeded example: #define C_Ds1307ControlRegAddress_U8  0x07u   // Address to access Ds1307 CONTROL register
    // write 0x07 to it, telling it that we want to access the control register
    
    //i2c_write(0x07);
    // see above
    
    //i2c_write(0x00);
    //i2c_stop();                          
}
 


uint8_t result;

uint8_t getSeconds(void) {
    // receive 1 byte (seconds)
    //i2c_start_wait(rtc_clock+I2C_READ);
    //result = i2c_readNak();                 
    //i2c_stop();
    result = 2;
    return result;
}




int main(void) {
    DDRD |= (1 << LED1);
    DDRD |= (1 << LED2);

    //USART_Init(MYUBRR);
    init_i2c();
    uint8_t count = 0;
    while (1) {
        
        uint8_t tmp = getSeconds();
        //USART_transmit(tmp);       
        //transmit_char(count + '0');
        count = count + 1;
        _delay_ms(3000);
        
        // flash two leds "count" times...since count is always growing
        // one can see if the chip crashed....started flashing from 0.
        flash_leds(count);
    }
}

[Matthias S. (Firma: matzetronics) (mschoeldgen)]

Julius schrieb:
> i2c_start_wait(rtc_clock+I2C_WRITE);

Das ist ein Wackeltanz und wird nie zurückkehren, wenn das Device ein 
Problem hat.
Probier mal:

uint8_t ret;
  ret = i2c_start(rtc_clock+I2C_WRITE);  // set device address and write mode
  if ( ret ) {
        /* failed to issue start condition, possibly no device found */
     i2c_stop();
// we can issue an error message here if the device failed to respond

     } else {
 /* issuing start condition ok, device accessible 
 we can now use i2c_write() to talk to the device*/

// and then issue 
  i2c_stop();                     // set stop conditon = release bus
  }

Denke daran, das wenn du die Soft-I²C Implementierung (i2cmaster.S) 
benutzt, in i2cmaster.S die benutzten Ports und Pins definierst. Das ist 
nicht nötig, wenn du twimaster.c inkludierst.

[Julius (Gast)]

Habe die i2cmaster.S angepasst auf:

 
#define SDA             1           
#define SCL             0          
#define SDA_PORT        PORTC       
#define SCL_PORT        PORTC

für Atmega32.
Das hatte ich bisher noch nirgends gelesen :(


Das init_i2c läuft jetzt durch, aber das Lesen der Sekunden klappt noch 
nicht.
Werde das Morgen Vormittag nochmal probieren.

[Matthias S. (Firma: matzetronics) (mschoeldgen)]

Julius schrieb:
> für Atmega32.
> Das hatte ich bisher noch nirgends gelesen :(

Die Soft-Implementierung von I²C ist eigentlich nur dann nötig, wenn der 
verwendete Controller kein TWI (aka I²C) Hardware Interface hat oder du 
Pins benutzen musst, die andere sind als die vom TWI Interface.
Beim Mega32 kannst du also i2cmaster.s rauswerfen und stattdessen 
twimaster.c mit kompilieren, dann wird das Hardware Interface des Mega32 
benutzt.

Für twimaster.c sind keine weiteren Pindefinitionen notwendig, da 
natürlich die Pins SCA und SDL benutzt werden. Das passt ja bei dir.

[Julius (Gast)]

Ah, danke für die Info.

Bin jetzt Erstmal mit der Software Implementierung weiter gekommen, der 
angehängte Code funktioniert auf einem ATmega16:

Ist jetzt auch ein anderes RTC Modul, kann sein das das erste defekt (zu 
heiß gelötet) oder Batterie leer war, aber zumindest der Code hier gibt 
schon einmal die Sekunden per Bluetooth aus.

Auf Android "Bluetooth Terminal" (Schwarzes Shell Symbol mit kleinem 
Bluetooth Zeichen in der rechten unteren Ecke) - Sehe den Author gerade 
nicht aber das Symbol ist einfach zu erkennen.


Problematisch ist jetzt noch die Umwandlung von uint8_t (Datenformat des 
I2C Chips) nach char (Eingabe für den Bluetooth Code)
Erstaunlich wieviele stumpfe Antworten es dafür gibt die man mit Google 
findet von denen keine funktioniert.

#include <avr/io.h>
#include <util/delay.h>
#include <i2cmaster.h> 


#define BAUD 9600
#define MYUBRR ((uint16_t) ((F_CPU / ((BAUD) * 16.0)) + .5) - 1)
#define LED1 PD6
#define LED2 PD7


// contains what the bluetooth module received
uint8_t data;

void USART_Init(unsigned int ubrr) {
    // set baud rate
    UBRRH = (unsigned char)(ubrr>>8);
    UBRRL = (unsigned char)(ubrr);
    // enable receiver, transmitter and interrupts for rx/tx
    UCSRB = (1<<RXEN) | (1<<TXEN) | (1<<RXCIE) | (1<< TXCIE);
}



void USART_transmit(char c) {
    while ( !(UCSRA & (1<<UDRE)) ) {}
    UDR = c;
}



void transmit_char(char c) {
    USART_transmit(c);
    USART_transmit('\r');
    USART_transmit('\n');
}



void send_string(char s[]) {
    int i =0;

    while (s[i] != 0x00) {
        USART_transmit(s[i]);
        i++;
    }
    USART_transmit('\r');
    USART_transmit('\n');

}


void flash_led1(uint8_t count) {
    for (int n=1; n<=count; n++) {
        PORTD |= (1 << LED1); // Turn on LED1
        //PORTD |= (1 << LED2); // Turn on LED2
        _delay_ms(300);
        PORTD &= ~(1 << LED1); // Turn off LED1
        //PORTD &= ~(1 << LED2); // Turn off LED2
        _delay_ms(300);
    }
}


void flash_led2(uint8_t count) {
    for (int n=1; n<=count; n++) {
        //PORTD |= (1 << LED1); // Turn on LED1
        PORTD |= (1 << LED2); // Turn on LED2
        _delay_ms(1000);
        //PORTD &= ~(1 << LED1); // Turn off LED1
        PORTD &= ~(1 << LED2); // Turn off LED2
        _delay_ms(1000);
    }
}


void flash_led2_long(uint8_t count) {
    for (int n=1; n<=count; n++) {
        //PORTD |= (1 << LED1); // Turn on LED1
        PORTD |= (1 << LED2); // Turn on LED2
        _delay_ms(3000);
        //PORTD &= ~(1 << LED1); // Turn off LED1
        PORTD &= ~(1 << LED2); // Turn off LED2
        _delay_ms(3000);
    }
}


void flash_all_leds(void) {
    for (uint8_t n = 0; n <= 3; n++) {
        PORTD |= (1 << LED1); // Turn on LED1
        PORTD |= (1 << LED2); // Turn on LED2
        _delay_ms(500);
        PORTD &= ~(1 << LED1); // Turn off LED1
        PORTD &= ~(1 << LED2); // Turn off LED2
        _delay_ms(500);
    }
}

/*
0xD0 = 1   1   0   1   0   0   0   0 = write
0xD1 = 1   1   0   1   0   0   0   1 = read

the first 6 bits contain the device id, and the last one tells the device if we want to read from it
or write to it
*/

// adress of the rtc clock device/chip
#define rtc_clock 0xD0



/* example: http://exploreembedded.com/wiki/Real_Time_Clock%28DS1307%29_with_AVR
void RTC_Init(void)
{
    I2C_Init();                             // Initialize the I2c module.
    I2C_Start();                            // Start I2C communication
 
    I2C_Write(C_Ds1307WriteMode_U8);        // Connect to DS1307 by sending its ID on I2c Bus
    I2C_Write(C_Ds1307ControlRegAddress_U8);// Select the Ds1307 ControlRegister to configure Ds1307
 
    I2C_Write(0x00);                        // Write 0x00 to Control register to disable SQW-Out
 
    I2C_Stop();                             // Stop I2C communication after initializing DS1307
}*/


// my init, adapted from the above
void init_i2c(void) {
    // initialize, taken from peter fleurys i2c example (he wrote the i2c code)
    i2c_init();
    // connect to the device and tell it that we want to write to it
    
    //i2c_start_wait(rtc_clock+I2C_WRITE);
    // this is from rtc.h from the exploreembeeded example: #define C_Ds1307ControlRegAddress_U8  0x07u   // Address to access Ds1307 CONTROL register
    // write 0x07 to it, telling it that we want to access the control register
    uint8_t ret;
    ret = i2c_start(rtc_clock+I2C_WRITE);  // set device address and write mode
    if ( ret ) {
        flash_led2_long(1);
        /* failed to issue start condition, possibly no device found */
        i2c_stop();
        // we can issue an error message here if the device failed to respond

     } else {
        flash_led1(1);
        i2c_write(0x07);
        // see above
    
        i2c_write(0x00);
        i2c_stop();     
    }
       
}


typedef struct {
      uint8_t sec;
      uint8_t min;
      uint8_t hour;
      uint8_t weekDay;
      uint8_t date;
      uint8_t month;
      uint8_t year;  
} rtc_t;

rtc_t rtc;

void setClock(rtc_t *rtc) {
  rtc->hour = 0x00; //  10:40:20 am
    rtc->min =  0x40;
    rtc->sec =  0x00;

    rtc->date = 0x01; //1st Jan 2016
    rtc->month = 0x01;
    rtc->year = 0x16;
    rtc->weekDay = 5;
    
  uint8_t ret;
    ret = i2c_start(rtc_clock+I2C_WRITE);  // set device address and write mode
    if ( ret ) {
        flash_led2_long(1);
        /* failed to issue start condition, possibly no device found */
        i2c_stop();
        // we can issue an error message here if the device failed to respond

     } else {
         i2c_write(0x00);
      i2c_write(rtc->sec);                    // Write sec from RAM address 00H
      i2c_write(rtc->min);                    // Write min from RAM address 01H
      i2c_write(rtc->hour);                    // Write hour from RAM address 02H
      i2c_write(rtc->weekDay);                // Write weekDay on RAM address 03H
      i2c_write(rtc->date);                    // Write date on RAM address 04H
      i2c_write(rtc->month);                    // Write month on RAM address 05H
      i2c_write(rtc->year);                    // Write year on RAM address 06h
      i2c_stop();
  }  
}
 


uint8_t result;

uint8_t getSeconds(void) {
    // receive 1 byte (seconds)
    
    /*i2c_start_wait(rtc_clock+I2C_READ);
    result = i2c_readNak();                 
    i2c_stop();
    result = 2;
    return result;*/

    uint8_t ret;
    ret = i2c_start(rtc_clock+I2C_WRITE);  // set device address and write mode
    if ( ret ) {
        flash_led2_long(3);
        /* failed to issue start condition, possibly no device found */
        i2c_stop();
        // we can issue an error message here if the device failed to respond

     } else {
        /* issuing start condition ok, device accessible 
        we can now use i2c_write() to talk to the device*/
          
        flash_led1(2);

        // request second ram adress
        i2c_write(0x00);
        i2c_stop();

        // _rep_start or _start? whats the difference?
        i2c_rep_start(rtc_clock+I2C_READ);
        result = i2c_readNak(); 
        i2c_stop();
    }
   return result;

    
}




int main(void) {
    DDRD |= (1 << LED1);
    DDRD |= (1 << LED2);

    // test the leds
    flash_all_leds();
    USART_Init(MYUBRR);
    init_i2c();
  setClock(&rtc);
    uint8_t count = 0;
    while (1) {
        
        uint8_t tmp = getSeconds();
        transmit_char(tmp);       
        //transmit_char(count + '0');
        count = count + 1;
        _delay_ms(2000);
        
        // flash LED1 "count" times to see if the program crashed
        
        //flash_led1(tmp);
        //flash_all_leds();
    }
}

[Matthias S. (Firma: matzetronics) (mschoeldgen)]

Julius schrieb:
> Problematisch ist jetzt noch die Umwandlung von uint8_t (Datenformat des
> I2C Chips) nach char (Eingabe für den Bluetooth Code)

Faule Leute mit Speicherplatz im Flash ziehen sich dafür die 'stdlib.h' 
ins Projekt und benutzen dann die 'itoa' Funktion. Allerdings gibts auch 
kleine Helferlein, die das ohne die stdlib hinkriegen, du solltest z.B. 
mal nach 'hex2asc' oder 'bin2asc' suchen.

[Julius (Gast)]

Ja, die itoa benutze ich natürlich liebend gerne.

Momentan zählt er die Sekunden von 0 bis 89 hoch, keine Ahnung.
Aber generell tut die itoa.
Ein Ausschnitt aus dem lauffähigen Code:

          // second, minute, hour, weekday, date, month, year
uint8_t time[] = {0x10,0x15,0x20, 0x01, 0x02, 0x04, 0x17};

void setClock(void) {
  
  uint8_t ret;
    ret = i2c_start(rtc_clock+I2C_WRITE);  // set device address and write mode
    if ( ret ) {
        flash_led2_long(1);
        /* failed to issue start condition, possibly no device found */
        i2c_stop();
        // we can issue an error message here if the device failed to respond

     } else {
    i2c_write(0x00);
    
    i2c_write(time[0]);
    i2c_write(time[1]);
    i2c_write(time[2]);
    i2c_write(time[3]);
    i2c_write(time[4]);
    i2c_write(time[5]);
    i2c_write(time[6]);

    i2c_stop();
  }

}
 


uint8_t result;

void getSeconds(void) {
    uint8_t ret;
    ret = i2c_start(rtc_clock+I2C_WRITE);  // set device address and write mode
    if ( ret ) {
        flash_led2_long(3);
        /* failed to issue start condition, possibly no device found */
        i2c_stop();
        // we can issue an error message here if the device failed to respond

     } else {
        /* issuing start condition ok, device accessible 
        we can now use i2c_write() to talk to the device*/
          
        flash_led1(2);

        // request second ram adress
        i2c_write(0x00);
        i2c_stop();

        // _rep_start or _start? whats the difference?
        i2c_rep_start(rtc_clock+I2C_READ);
        
    time[0] = i2c_readAck();
    time[1] = i2c_readAck();
    time[2] = i2c_readAck();
    time[3] = i2c_readAck();
    time[4] = i2c_readAck();
    time[5] = i2c_readAck();
    time[6] = i2c_readNak();


        i2c_stop();
    }

    
}



int main(void) {
    DDRD |= (1 << LED1);
    DDRD |= (1 << LED2);

    // test the leds
    flash_all_leds();
    USART_Init(MYUBRR);
    init_i2c();
  
    setClock();
 
    

  char output[7][4];
    while (1) {
        
        getSeconds();


    for (uint8_t n=0; n<sizeof(time); n++) {
      itoa(time[n], output[n], 10);
    }

       

    send_string(output[2]);
    send_string(output[1]);
    send_string(output[0]);
  
    send_string(" ");


       
        _delay_ms(1000);
      
    }
}