MSP432E401Y: i2c driverlib code for a particular sensor (slf3s-4000b) product id

Hello David,

So without a sensor that reacts correctly I can't fully test this, but here is what I believe should work:

//*****************************************************************************
//
// This function will read three 8-bit data from the I2C slave. The first
// two 8-bit data forms the humidity data while the last 8-bit data is the
// checksum.  This function illustrates three different I2C burst mode
// commands to read the I2C slave device.
//
//*****************************************************************************
void
I2CReadSensor(uint32_t * ui32Cmd1, uint32_t * ui32Cmd2, uint32_t * pui32DataRx)
{
    uint8_t ui8DataIndex = 0;

    /* Put the Slave Address on the bus for Write */
    MAP_I2CMasterSlaveAddrSet(I2C1_BASE, SLAVE_ADDRESS, false);

    /* Write the first byte of the command to the bus */
    MAP_I2CMasterDataPut(I2C1_BASE, ui32Cmd1[0]);
    MAP_I2CMasterControl(I2C1_BASE, I2C_MASTER_CMD_BURST_SEND_START);

    /* Wait until the I2C transaction is complete. */
    while(MAP_I2CMasterBusy(I2C1_BASE))
    {
    }

    /* Send the second byte of the command to the bus */
    MAP_I2CMasterDataPut(I2C1_BASE, ui32Cmd1[1]);
    MAP_I2CMasterControl(I2C1_BASE, I2C_MASTER_CMD_BURST_SEND_CONT);

    /* Wait until the I2C transaction is complete. */
    while(MAP_I2CMasterBusy(I2C1_BASE))
    {
    }

    /* Put the Slave Address on the bus for Write */
    MAP_I2CMasterSlaveAddrSet(I2C1_BASE, SLAVE_ADDRESS, false);

    /* Write the first byte of the command to the bus */
    MAP_I2CMasterDataPut(I2C1_BASE, ui32Cmd2[0]);
    MAP_I2CMasterControl(I2C1_BASE, I2C_MASTER_CMD_BURST_SEND_START);

    /* Wait until the I2C transaction is complete. */
    while(MAP_I2CMasterBusy(I2C1_BASE))
    {
    }

    /* Send the second byte of the command to the bus */
    MAP_I2CMasterDataPut(I2C1_BASE, ui32Cmd2[1]);
    MAP_I2CMasterControl(I2C1_BASE, I2C_MASTER_CMD_BURST_SEND_CONT);
    
    /* Wait until the I2C transaction is complete. */
    while(MAP_I2CMasterBusy(I2C1_BASE))
    {
    }

    /* Modify the data direction to true, so that seeing the address will
     * indicate that the I2C Master is initiating a read from the slave. */
    MAP_I2CMasterSlaveAddrSet(I2C1_BASE, SLAVE_ADDRESS, true);

    /* Setup for first read.  Use I2C_MASTER_CMD_BURST_RECEIVE_START
     * to start a burst mode read.  The I2C master continues to own
     * the bus at the end of this transaction. */
    MAP_I2CMasterControl(I2C1_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START);

    /* Wait until master module is done transferring.
     * The I2C module has a delay in setting the Busy flag in the register so
     * there needs to be a delay before checking the Busy bit.  The below loops
     * wait until the Busy flag is set, and then wait until it is cleared to
     * indicate that the transaction is complete.  This can take up to 633 CPU
     * cycles @ 100 kbit I2C Baud Rate and 120 MHz System Clock.  Therefore, a
     * while loop is used instead of SysCtlDelay. */
    while(!MAP_I2CMasterBusy(I2C1_BASE))
    {
    }
    while(MAP_I2CMasterBusy(I2C1_BASE))
    {
    }

    /* Read the first byte data from the slave. */
    pui32DataRx[ui8DataIndex++] = MAP_I2CMasterDataGet(I2C1_BASE);

    while (ui8DataIndex < 17)
    {
        /* Setup for the next read.  Use I2C_MASTER_CMD_BURST_RECEIVE_CONT
         * to continue the burst mode read.  The I2C master continues to own
         * the bus at the end of this transaction. */
        MAP_I2CMasterControl(I2C1_BASE, I2C_MASTER_CMD_BURST_RECEIVE_CONT);

        /* Wait until master module is done transferring. */
        while(!MAP_I2CMasterBusy(I2C1_BASE))
        {
        }
        while(MAP_I2CMasterBusy(I2C1_BASE))
        {
        }

        /* Read the next byte data from the slave. */
        pui32DataRx[ui8DataIndex++] = MAP_I2CMasterDataGet(I2C1_BASE);
    }

    /* Setup for the third read.  Use I2C_MASTER_CMD_BURST_RECEIVE_FINISH
     * to terminate the I2C transaction.  At the end of this transaction,
     * the STOP bit will be issued and the I2C bus is returned to the
     * Idle state. */
    MAP_I2CMasterControl(I2C1_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH);

    /* Wait until master module is done transferring. */
    while(!MAP_I2CMasterBusy(I2C1_BASE))
    {
    }
    while(MAP_I2CMasterBusy(I2C1_BASE))
    {
    }

    /* Note the third 8-bit data is the checksum byte.  It will be
     * left to the users as an exercise if they want to verify if the
     * checksum is correct. */
    pui32DataRx[ui8DataIndex++] = MAP_I2CMasterDataGet(I2C1_BASE);
}

int main(void)
{
    uint32_t systemClock;

    /* Variables for I2C data and state machine */
    uint32_t ui32Cmd1[2] = {0xAA, 0xBB};
    uint32_t ui32Cmd2[2] = {0xCC, 0xDD};
    uint32_t ui32SensorData[18] = {0x00};

    /* Configure the system clock for 120 MHz */
    systemClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN |
                                          SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480),
                                          120000000);

    /* Enable clocks to GPIO Port G and configure pins as I2C */
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOG);
    while(!(MAP_SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOG)))
    {
    }

    MAP_GPIOPinConfigure(GPIO_PG0_I2C1SCL);
    MAP_GPIOPinConfigure(GPIO_PG1_I2C1SDA);
    MAP_GPIOPinTypeI2C(GPIO_PORTG_BASE, GPIO_PIN_1);
    MAP_GPIOPinTypeI2CSCL(GPIO_PORTG_BASE, GPIO_PIN_0);

    /* Since there are no board pull up's we shall enable the weak internal
     * pull up */
    GPIOG->PUR |= (GPIO_PIN_1 | GPIO_PIN_0);

    /* Enable the clock to I2C-1 module and configure the I2C Master */
    MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C1);
    while(!(MAP_SysCtlPeripheralReady(SYSCTL_PERIPH_I2C1)))
    {
    }

    /* Configure the I2C Master in standard mode and enable interrupt for Data
     * completion, NAK and Stop condition on the bus */
    MAP_I2CMasterInitExpClk(I2C1_BASE, systemClock, false);

    I2CReadSensor(&ui32Cmd1[0], &ui32Cmd2[0], &ui32SensorData[0]);

    while(1)
    {

    }
}

(Made two small edits 5 minutes after initial posting)

Best Regards,

Ralph Jacobi

Hi Ralph,

Thanks this resolved my issue. The product number and serial number are correctly displayed.

David Nyarko