瑞萨MCU的硬件IIC总线不能挂载多个设备吗？

闲花野草逢春生

如题，在FSP设置内只能设定一个从设备地址，如果要一个总线挂载多个设备怎么操作呢？

RA_Lance

可以通过R_IIC_MASTER_SlaveAddressSet()更改从设备地址。Multiple Slave devices on the same channel (bus)

This example demonstrates how a single IIC driver can be used to communicate with different slave devices which are on the same channel.

NoteThe callback function from the first example applies to this example as well.
iic_master_instance_ctrl_t g_i2c_device_ctrl_2;
i2c_master_cfg_t           g_i2c_device_cfg_2 =
{
    .channel       = I2C_CHANNEL,
    .rate          = I2C_MASTER_RATE_STANDARD,
    .slave         = I2C_SLAVE_TEMP_SENSOR,
    .addr_mode     = I2C_MASTER_ADDR_MODE_7BIT,
    .p_callback    = i2c_callback,     // Callback
    .p_context     = &g_i2c_device_ctrl_2,
    .p_transfer_tx = NULL,
    .p_transfer_rx = NULL,
    .p_extend      = &g_iic_master_cfg_extend
};

void single_channel_multi_slave (void)
{
    fsp_err_t err;
    uint32_t  timeout_ms = I2C_TRANSACTION_BUSY_DELAY;

    err = R_IIC_MASTER_Open(&g_i2c_device_ctrl_2, &g_i2c_device_cfg_2);

    /* Handle any errors. This function should be defined by the user. */
    assert(FSP_SUCCESS == err);

    /* Clear the recieve buffer */
    memset(g_i2c_rx_buffer, '0', I2C_BUFFER_SIZE_BYTES);

    /* Read data from I2C slave */
    g_i2c_callback_event = I2C_MASTER_EVENT_ABORTED;
    err = R_IIC_MASTER_Read(&g_i2c_device_ctrl_2, &g_i2c_rx_buffer[0], I2C_BUFFER_SIZE_BYTES, false);
    assert(FSP_SUCCESS == err);

    while ((I2C_MASTER_EVENT_RX_COMPLETE != g_i2c_callback_event) && timeout_ms)
    {
        R_BSP_SoftwareDelay(1U, BSP_DELAY_UNITS_MILLISECONDS);
        timeout_ms--;;
    }

    if (I2C_MASTER_EVENT_ABORTED == g_i2c_callback_event)
    {
        __BKPT(0);
    }

    /* Send data to I2C slave on the same channel */
    err = R_IIC_MASTER_SlaveAddressSet(&g_i2c_device_ctrl_2, I2C_SLAVE_DISPLAY_ADAPTER, I2C_MASTER_ADDR_MODE_7BIT);
    assert(FSP_SUCCESS == err);

    g_i2c_tx_buffer[0]   = 0xAA;       // NOLINT
    g_i2c_tx_buffer[1]   = 0xBB;       // NOLINT
    g_i2c_callback_event = I2C_MASTER_EVENT_ABORTED;
    timeout_ms           = I2C_TRANSACTION_BUSY_DELAY;
    err = R_IIC_MASTER_Write(&g_i2c_device_ctrl_2, &g_i2c_tx_buffer[0], 2U, false);
    assert(FSP_SUCCESS == err);

    while ((I2C_MASTER_EVENT_TX_COMPLETE != g_i2c_callback_event) && timeout_ms)
    {
        R_BSP_SoftwareDelay(1U, BSP_DELAY_UNITS_MILLISECONDS);
        timeout_ms--;;
    }

    if (I2C_MASTER_EVENT_ABORTED == g_i2c_callback_event)
    {
        __BKPT(0);
    }
}