I2 C CCS мульти чтение MSP430g2553

Question

Мне нужно связаться с датчиком через I2 C. Датчик MMA 7455: https://www.nxp.com/docs/en/data-sheet/MMA7455L.pdf. Мне нужно прочитать регистры: $ 06, $ 07 и $ 08. Я не уверен, почему это не работает. Я вижу на линии последовательной передачи данных высокий сигнал с падением до 0 каждые 25 мс. На линии последовательной синхронизации инвертируется. У меня есть нагрузочные резисторы 10 кОм, подключенные к линиям SDA и SCL.

// Include's
//__________________________________________________________________
#include <msp430.h>

//__________________________________________________________________
// Define's & Variable
//__________________________________________________________________
typedef enum {MASTER,SLAVE} i2cMode;
typedef enum {SEVEN,TEN} AddresLength;
typedef enum {NSTART,START} Start;
#define TxBuffer UCB0TXBUF
#define RxBuffer UCB0RXBUF
unsigned int TxRegister;
unsigned int RxData;
unsigned int TxData;

//__________________________________________________________________
// Prototype's
//__________________________________________________________________

void i2c_init(unsigned char i2cmode,unsigned char addresLength);    // Initializer I2C
void i2c_User_Addres(unsigned int adr);                             // Make a address for this µc
void i2c_Slave_Addres(unsigned int adr);                            // Address for the slave
void i2c_start_codon(void);                                         // Just sending a start codon
void i2c_rx_start(void);                                            // Receive mode with start codon
void i2c_rx(unsigned int start);                                    // Receive mode without start codon
void i2c_tx_start(void);                                            // Transmit mode with start codon
void i2c_tx(void);                                                  // Transmit mode without start codon
void i2c_Stop(void);                                                // Stop codon
void i2c_NACK(void);                                                // Not acknowlegde
void ReadAcellerometer(void);                                       // Accellerometer reading

//__________________________________________________________________
// main.c
//__________________________________________________________________
int main(void)
{
    BCSCTL1   = CALBC1_16MHZ;                                       // Set DCO range
    DCOCTL    = CALDCO_16MHZ;                                       // Set DCO step and modulation

    i2c_init(MASTER, SEVEN);                                        // Setup this µc for I2C
    i2c_User_Addres(0x08);                                          // Give this µc a I2C Addres
    i2c_Slave_Addres(0x1D);                                         // Slave addres or coversation

    ReadAcellerometer();

    return 0;
}

//__________________________________________________________________
// Functie's
//__________________________________________________________________

void ReadAcellerometer(void)
{
    TxBuffer = 0x18;                                                // Fill TX informatie
    i2c_tx_start();
    i2c_rx(START);
    i2c_start_codon();
    i2c_NACK();
    i2c_Stop();
}

//__________________________________________________________________
// Functie's I2C
//__________________________________________________________________

#pragma vector = USCIAB0TX_VECTOR
__interrupt void USCIAB0TX_ISR(void)
{
  if (~UCTR)                                                        // Recieve?
      {
      UCB0CTL1 |= UCTXSTP;                                          // I2C stop condition
      RxData = RxBuffer;                                            // Get RX data
      IFG2 &= ~UCB0TXIFG;                                           // Clear USCI_B0 TX int flag
      __bic_SR_register_on_exit(CPUOFF);                            // Exit LPM0

      }
  else if (UCTR)                                                   // Transmit?
  {
      IFG2 &= ~UCB0TXIFG;                                           // Clear USCI_B0 TX int flag
      __bic_SR_register_on_exit(CPUOFF);                            // Exit LPM0
  }
}

//---------I2C INICIALIZATION----------------------


void i2c_init(unsigned char i2cmode, unsigned char addresLength )
{
        P1SEL |= BIT6 + BIT7;                                       // Assign I2C pins to USCI_B0
        P1SEL2|= BIT6 + BIT7;                                       // Assign I2C pins to USCI_B0
        UCB0CTL1 |= UCSWRST;                                        // Enable SW reset
        UCB0CTL0 = (UCA10 << addresLength) + (UCSLA10 << addresLength) + (UCMST<<i2cmode) + (UCMODE_3<< i2cmode )+ UCSYNC;         // I2C Master, synchronous mode
        UCB0CTL1 = UCSSEL_2 + UCSWRST;                              // Use SMCLK, keep SW reset
        if (~(i2cmode))
        {
            UCA0MCTL |= UCBRS_7;                                    // CLK wave modulation see table 15-4 BRCLK = 1MHz; SCL = 100kHz;
            UCB0BR0 = 12;                                           // fSCL = SMCLK/12 = ~100kHz
            UCB0BR1 = 0;
            UCB0CTL1 &= ~UCSWRST;                                   // Clear SW reset, resume operation
        }
        IE2 |= UCB0RXIE + UCB0TXIE;                                 // Enable RX en TX interrupt
}

//----------User's Addres----------
void i2c_User_Addres(unsigned int adr)
{
    UCB0I2COA = (1<<adr);                                           // Address for this µc
}
//----------CHANGE OF ADDRESS--------------
void i2c_Slave_Addres(unsigned int adr)
{
    UCB0I2CSA = adr;                                                // Address for the slave µc
}

//----------RECEIVE DATA WITH START CODON----------
void i2c_rx_start(void)
{
        while (UCB0CTL1 & UCTXSTP);                                 // Ensure stop codon got sent
        UCB0CTL1 &= ~UCTR;                                          // Receive Mode
        UCB0CTL1 |= UCTXSTT;                                        // Send start codon
        while (UCB0CTL1 & UCTXSTT);                                 // Start codon sent?
        __bis_SR_register(CPUOFF + GIE);                            // Enter LPM0 w/ interrupts
}

//----------RECEIVE DATA----------
void i2c_rx(unsigned int start)
{
        UCB0CTL1 &= ~UCTR;                                          // Receive Mode
        if (start) UCB0CTL1 |= UCTXSTT;                             // Send start codon
        __bis_SR_register(CPUOFF + GIE);                            // Enter LPM0 w/ interrupts
}

//----------SEND DATA------
void i2c_tx(void)
{
        UCB0CTL1 |= UCTR;                                           // Transmit mode
        __bis_SR_register(CPUOFF + GIE);                            // Enter LPM0 w/ interrupts
}

//----------SEND DATA WITH START CODON------
void i2c_tx_start(void)
{
    while (UCB0CTL1 & UCTXSTP);                                     // Ensure stop condition got sent
    UCB0CTL1 |= UCTR;                                               // Transmit mode
    UCB0CTL1 |= UCTXSTT;                                            // I2C start codon
    __bis_SR_register(CPUOFF + GIE);
}


//---------------STOP-------------------------
void i2c_start_codon(void)
{
    UCB0CTL1 |= UCTXSTT;                                            // I2C start codon
}

//---------------STOP-------------------------
void i2c_Stop(void)
{
    while((UCB0STAT & BUSY)!= 0);                                   // Wait to finish the byte
    UCB0CTL1 |= UCTXSTP;                                            // I2C Stop codon
    while(UCB0CTL1 & UCTXSTP);                                      // Ensure the stop Condon is send
}

//---------------NACK---------------
void i2c_NACK(void)
{
    UCB0CTL1 |= UCTXNACK;                                           // Not Acknowlegded
}

//__________________________________________________________________
// End
//__________________________________________________________________