[参考译文] TCA9534：无法使用 I2C4从微控制器 TM4C1294ncpdt 驱动 IO 扩展器 TCA9534PWR

void I2c_init()
{
    //#######INITIALIZATION############

            // The I2C3 peripheral must be enabled before use.
            SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C3);
            SysCtlPeripheralReset(SYSCTL_PERIPH_I2C3);

            // The I2C4 peripheral must be enabled before use.
            SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C4);
            SysCtlPeripheralReset(SYSCTL_PERIPH_I2C4);

            SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOK);

            GPIOPinConfigure(GPIO_PK4_I2C3SCL);
            GPIOPinConfigure(GPIO_PK5_I2C3SDA);

            GPIOPinTypeI2CSCL(GPIO_PORTK_BASE, GPIO_PIN_4);
            GPIOPinTypeI2C(GPIO_PORTK_BASE, GPIO_PIN_5);
            I2CMasterInitExpClk(I2C3_BASE, g_ui32SysClock, false);
           // I2CMasterSlaveAddrSet(I2C3_BASE, SLAVE_ADDRESS , false); // slave address to 0x20
            I2CMasterEnable(I2C3_BASE);



            GPIOPinConfigure(GPIO_PK6_I2C4SCL);
            GPIOPinConfigure(GPIO_PK7_I2C4SDA);

            GPIOPinTypeI2CSCL(GPIO_PORTK_BASE, GPIO_PIN_6);
            GPIOPinTypeI2C(GPIO_PORTK_BASE, GPIO_PIN_7);
            I2CMasterInitExpClk(I2C4_BASE, g_ui32SysClock, false);
            I2CMasterSlaveAddrSet(I2C4_BASE, 0x27 , false); // slave address to 0x27
            I2CMasterEnable(I2C4_BASE);

            I2CMasterGlitchFilterConfigSet(I2C3_BASE, I2C_MASTER_GLITCH_FILTER_2);
            I2CMasterGlitchFilterConfigSet(I2C4_BASE, I2C_MASTER_GLITCH_FILTER_2);

      }

void I2CSend4(uint8_t slave_addr, uint8_t num_of_args, ...)
{
    uint8_t i =0;
    // Tell the master module what address it will place on the bus when
    // communicating with the slave.
    I2CMasterSlaveAddrSet(I2C4_BASE, slave_addr, false);

    //stores list of variable number of arguments
    va_list vargs;

    //specifies the va_list to "open" and the last fixed argument
    //so vargs knows where to start looking
    va_start(vargs, num_of_args);

    //put data to be sent into FIFO
    I2CMasterDataPut(I2C4_BASE, va_arg(vargs, uint32_t));

    //if there is only one argument, we only need to use the
    //single send I2C function
    if(num_of_args == 1)
    {
        //Initiate send of data from the MCU
        I2CMasterControl(I2C4_BASE, I2C_MASTER_CMD_SINGLE_SEND);

        // Wait until MCU is done transferring.
        while(I2CMasterBusy(I2C4_BASE));

        //"close" variable argument list
        va_end(vargs);
    }

    //otherwise, we start transmission of multiple bytes on the
    //I2C bus
    else
    {
        //Initiate send of data from the MCU
        I2CMasterControl(I2C4_BASE, I2C_MASTER_CMD_BURST_SEND_START);

        // Wait until MCU is done transferring.
        while(I2CMasterBusy(I2C4_BASE));

        //send num_of_args-2 pieces of data, using the
        //BURST_SEND_CONT command of the I2C module
        for( i = 1; i < (num_of_args - 1); i++)
        {
            //put next piece of data into I2C FIFO
            I2CMasterDataPut(I2C4_BASE, va_arg(vargs, uint32_t));
            //send next data that was just placed into FIFO
            I2CMasterControl(I2C4_BASE, I2C_MASTER_CMD_BURST_SEND_CONT);

            // Wait until MCU is done transferring.
            while(I2CMasterBusy(I2C4_BASE));
        }

        //put last piece of data into I2C FIFO
        I2CMasterDataPut(I2C4_BASE, va_arg(vargs, uint32_t));
        //send next data that was just placed into FIFO
        I2CMasterControl(I2C4_BASE, I2C_MASTER_CMD_BURST_SEND_FINISH);
        // Wait until MCU is done transferring.
        while(I2CMasterBusy(I2C4_BASE));

        //"close" variable args list
        va_end(vargs);
    }
}
//read specified register on slave device
uint32_t I2CReceive4(uint32_t slave_addr, uint8_t reg)
{
    //specify that we are writing (a register address) to the
    //slave device
    I2CMasterSlaveAddrSet(I2C4_BASE, slave_addr, false);

    //specify register to be read
    I2CMasterDataPut(I2C4_BASE, reg);

    //send control byte and register address byte to slave device
    I2CMasterControl(I2C4_BASE, I2C_MASTER_CMD_BURST_SEND_START);

    //wait for MCU to finish transaction
    while(I2CMasterBusy(I2C4_BASE));

    //specify that we are going to read from slave device
    I2CMasterSlaveAddrSet(I2C4_BASE, slave_addr, true);

    //send control byte and read from the register we
    //specified
    I2CMasterControl(I2C4_BASE, I2C_MASTER_CMD_SINGLE_RECEIVE);

    //wait for MCU to finish transaction
    while(I2CMasterBusy(I2C4_BASE));

    //return data pulled from the specified register
    return I2CMasterDataGet(I2C4_BASE);
}

void Set_output()
{
   I2CSend4(SLAVE_DR1, 2, 0x03, 0x00); 
}

void Write_output(uint8_t pin)
{
   I2CSend4(SLAVE_DR1,2, 0x01, pin);
}

这些 I²C Ω 波形看起来不错。

您遇到的问题是什么？

您好、Ramesh、

您写入配置寄存器以将所有 p 端口设置为输出、但您是否也写入输出端口寄存器以在高逻辑电平和低逻辑电平之间切换？  

此致、

泰勒