I2C Probleme mit PIC32 MX250F128B - Master Bus Collision

// I2C Interface

#define WM8731_I2C_MODULE I2C1

#define WM8731_I2C_BAUDRATE 100000 // 100 kHz

#define WM8731_I2C_ADDRESS 0x1A      // -> 0x34 for Write

void initWM8731()

{

     // I2C pins as input

    TRISBbits.TRISB8 = 1;

    TRISBbits.TRISB9 = 1;

    // Setup I2C interface

    I2CConfigure(WM8731_I2C_MODULE, 0);

    I2CSetFrequency(WM8731_I2C_MODULE, GetPeripheralClock(), WM8731_I2C_BAUDRATE);

}

// This code is adapted from Microchip Audio Accessory Board

static bool WM8731SendReg(WM8731_REGISTER reg, uint16_t cmd)

{

    // register address is 7 bit, command is 9 bit

    reg <<= 1;

    reg |= ((cmd & 0x0100) >> 8);

    cmd &= 0xFF;

    I2CEnable(WM8731_I2C_MODULE, true);

    while(I2CBusIsIdle(WM8731_I2C_MODULE) == false);

    if(I2CStart(WM8731_I2C_MODULE) != I2C_SUCCESS)

    {

             I2CStop(WM8731_I2C_MODULE);

             while(!(I2CGetStatus(WM8731_I2C_MODULE) & I2C_STOP));

             I2CEnable(WM8731_I2C_MODULE, false);

             return false;

    }

    while(!(I2CGetStatus(WM8731_I2C_MODULE) & I2C_START));

    if(I2CSendByte(WM8731_I2C_MODULE, (WM8731_I2C_ADDRESS << 1)) != I2C_SUCCESS)

    {

            I2CStop(WM8731_I2C_MODULE);

            while(!(I2CGetStatus(WM8731_I2C_MODULE) & I2C_STOP));

            I2CEnable(WM8731_I2C_MODULE, false);

            return false;

    }

    while(!I2CTransmissionHasCompleted(WM8731_I2C_MODULE));

    if(I2CByteWasAcknowledged(WM8731_I2C_MODULE) == false)

    {

            I2CStop(WM8731_I2C_MODULE);

            while(!(I2CGetStatus(WM8731_I2C_MODULE) & I2C_STOP));

            I2CEnable(WM8731_I2C_MODULE, false);

            return false;

    }

    while (!I2CBusIsIdle(WM8731_I2C_MODULE));

 //-----------------------------------------------------------------------

 // MAYBE HERE IS THE PROBLEM

 // because this byte isn't transmitted (see logic analyzer screenshot)

 //-----------------------------------------------------------------------

    if(I2CSendByte(WM8731_I2C_MODULE, reg) != I2C_SUCCESS)

    {

            I2CStop(WM8731_I2C_MODULE);

            while(!(I2CGetStatus(WM8731_I2C_MODULE) & I2C_STOP));

            I2CEnable(WM8731_I2C_MODULE, false);

            return false;

    }

    while(!I2CTransmissionHasCompleted(WM8731_I2C_MODULE));

    if(I2CByteWasAcknowledged(WM8731_I2C_MODULE) == false)

    {

            I2CStop(WM8731_I2C_MODULE);

            while(!(I2CGetStatus(WM8731_I2C_MODULE) & I2C_STOP));

            I2CEnable(WM8731_I2C_MODULE, false);

            return false;

    }

    while (!I2CBusIsIdle(WM8731_I2C_MODULE));

    if(I2CSendByte(WM8731_I2C_MODULE, cmd) != I2C_SUCCESS)

    {

//-----------------------------------------------------------------------

// HERE I GET THE "I2C_MASTER_BUS_COLLISION" ERROR         

//-----------------------------------------------------------------------

            I2CStop(WM8731_I2C_MODULE);

            while(!(I2CGetStatus(WM8731_I2C_MODULE) & I2C_STOP));

            I2CEnable(WM8731_I2C_MODULE, false);

            return false;

    }

    while(!I2CTransmissionHasCompleted(WM8731_I2C_MODULE));

    if(I2CByteWasAcknowledged(WM8731_I2C_MODULE) == false)

    {

            I2CStop(WM8731_I2C_MODULE);

            while(!(I2CGetStatus(WM8731_I2C_MODULE) & I2C_STOP));

            I2CEnable(WM8731_I2C_MODULE, false);

            return false;

    }

    while (!I2CBusIsIdle(WM8731_I2C_MODULE));

    I2CStop(WM8731_I2C_MODULE);

    while(!(I2CGetStatus(WM8731_I2C_MODULE) & I2C_STOP));

    I2CEnable(WM8731_I2C_MODULE, false);

    return true;

}

//* Oscillator Settings

#pragma config FNOSC = PRIPLL // Oscillator selection

#pragma config POSCMOD = XT // Primary oscillator mode

#pragma config FPLLIDIV = DIV_2 // PLL input divider

#pragma config FPLLMUL = MUL_20 // PLL multiplier

#pragma config FPLLODIV = DIV_2 // PLL output divider

#pragma config FPBDIV = DIV_1 // Peripheral bus clock divider

#pragma config FSOSCEN = OFF // Secondary oscillator enable

//* Clock control settings

#pragma config IESO = OFF // Internal/external clock switchover

#pragma config FCKSM = CSECME // Clock switching (CSx)/Clock monitor (CMx)

#pragma config OSCIOFNC = OFF // Clock output on OSCO pin enable

//* USB Settings

#pragma config UPLLEN = ON // USB PLL enable

#pragma config UPLLIDIV = DIV_2 // USB PLL input divider

#pragma config FVBUSONIO = OFF // Make VBUSON a GPIO pin

#pragma config FUSBIDIO = OFF // Controlled by port function

//* Other Peripheral Device settings

#pragma config FWDTEN = OFF // Watchdog timer enable

#pragma config WDTPS = PS1024 // Watchdog timer postscaler

#pragma config WINDIS = OFF

#pragma config JTAGEN = OFF // JTAG port disabled

//* Code Protection settings

#pragma config CP = OFF // Code protection

#pragma config BWP = OFF // Boot flash write protect

#pragma config PWP = OFF // Program flash write protect

//* Debug settings

#pragma config ICESEL = ICS_PGx1 // ICE/ICD Comm Channel Select

//* Reconfiguration

#pragma config PMDL1WAY = ON // Disallow multiple reconfigurations

#pragma config IOL1WAY = ON // Disallow multiple reconfigurations