Part Number: MSP430FR5994
Other Parts Discussed in Thread: LDC1614EVM, LDC1614

Hello everyone!

I'm try to control LDC1614EVM using my MSP430FR5994launchpad but without success in read mode.

Here is the test, when MSP read the LDC1614 manufacture_id, the LDC should answer 0x5449(MSB:0x54, LSB 0x49)

The IIC configure code is as fellows:

void IIC_init(void){

    //set the I2C IO
    GPIO_setAsPeripheralModuleFunctionInputPin(GPIO_PORT_P7, GPIO_PIN0+GPIO_PIN1, GPIO_PRIMARY_MODULE_FUNCTION);

    EUSCI_B_I2C_initMasterParam iic_param = {0};

    iic_param.selectClockSource = EUSCI_B_I2C_CLOCKSOURCE_SMCLK;
    iic_param.i2cClk = CS_getSMCLK();
    iic_param.dataRate = EUSCI_B_I2C_SET_DATA_RATE_400KBPS;
    iic_param.autoSTOPGeneration = EUSCI_B_I2C_NO_AUTO_STOP;
    iic_param.byteCounterThreshold = 1;

    EUSCI_B_I2C_initMaster(EUSCI_B2_BASE, & iic_param);

    //set slave address
    EUSCI_B_I2C_setSlaveAddress(EUSCI_B2_BASE, LDC_ADDRESS);

    //enable IIC
    EUSCI_B_I2C_enable(EUSCI_B2_BASE);

    //clear IIC interrupt
    EUSCI_B_I2C_clearInterrupt(EUSCI_B2_BASE, EUSCI_B_I2C_RECEIVE_INTERRUPT0 + EUSCI_B_I2C_BYTE_COUNTER_INTERRUPT + EUSCI_B_I2C_NAK_INTERRUPT);
//
    //Enable master interrupt
//    EUSCI_B_I2C_enableInterrupt(EUSCI_B2_BASE, EUSCI_B_I2C_RECEIVE_INTERRUPT0);
    while(EUSCI_B_I2C_isBusBusy(EUSCI_B2_BASE));

    printf("I2C in Master mode initial finish!\r\n");
    return;
}

after, when the key interrupt is detected,MSP read the LDC's manufacture_id,here is the read code.

uint16_t IIC_Read_Bytes(uint8_t RegAddr, uint8_t length){

    i2c_rx_buf_len = length;
    uint8_t data1,data2;
    uint16_t data_test;

    while(EUSCI_B_I2C_isBusBusy(EUSCI_B2_BASE));

    EUSCI_B_I2C_setMode(EUSCI_B2_BASE, EUSCI_B_I2C_TRANSMIT_MODE);

    EUSCI_B_I2C_masterSendSingleByte(EUSCI_B2_BASE, RegAddr);

    //receive
    EUSCI_B_I2C_setMode(EUSCI_B2_BASE, EUSCI_B_I2C_RECEIVE_MODE);

    EUSCI_B_I2C_masterReceiveStart(EUSCI_B2_BASE);
    while(EUSCI_B_I2C_isBusBusy(EUSCI_B2_BASE));

    data1 = EUSCI_B_I2C_masterReceiveMultiByteNext(EUSCI_B2_BASE);
    data2 = EUSCI_B_I2C_masterReceiveMultiByteFinish(EUSCI_B2_BASE);
    EUSCI_B_I2C_masterReceiveMultiByteStop(EUSCI_B2_BASE);
    EUSCI_B_I2C_masterIsStopSent(EUSCI_B0_BASE);
    while(EUSCI_B_I2C_isBusBusy(EUSCI_B2_BASE));
    data_test = data1<<8 | data2;
    return data_test;
}

when I first push the button ,The oscillogram show as fellows:

the MSP continues to work,

PS : I used to trying debug step by step, it seems   data1 = EUSCI_B_I2C_masterReceiveMultiByteNext(EUSCI_B2_BASE)  return empty.

 then I push the button again,The The oscillogram show as fellows:

Now MSP is Loop in  -> while (!(HWREG16(baseAddress + OFS_UCBxIFG) & UCTXIFG)) ; 

 ALSO, I try read LDC data with another way, as fellows:

uint16_t IIC_Read_Bytes(uint8_t RegAddr, uint8_t length){

    i2c_rx_buf_len = length;
    uint8_t data1,data2;
    uint16_t data_test;

    while(EUSCI_B_I2C_isBusBusy(EUSCI_B2_BASE));

    EUSCI_B_I2C_setMode(EUSCI_B2_BASE, EUSCI_B_I2C_TRANSMIT_MODE);

    EUSCI_B_I2C_masterSendSingleByte(EUSCI_B2_BASE, RegAddr);

    //receive
    EUSCI_B_I2C_setMode(EUSCI_B2_BASE, EUSCI_B_I2C_RECEIVE_MODE);

    EUSCI_B_I2C_masterReceiveStart(EUSCI_B2_BASE);
    while(EUSCI_B_I2C_isBusBusy(EUSCI_B2_BASE));
    data1 = EUSCI_B_I2C_masterReceiveMultiByteNext(EUSCI_B2_BASE);
    data2 = EUSCI_B_I2C_masterReceiveMultiByteNext(EUSCI_B2_BASE);
    EUSCI_B_I2C_masterReceiveMultiByteStop(EUSCI_B2_BASE);
    EUSCI_B_I2C_masterIsStopSent(EUSCI_B0_BASE);

    while(EUSCI_B_I2C_isBusBusy(EUSCI_B2_BASE));

    data_test = data1<<8 | data2;
    return data_test;
}

The The oscillogram show as fellows:

they lost LSB again, But in this way, the MSP do not fall into the loop.

How can I get the data properly?

thank you for your attention and best regards!