在freeRTOS中用ESP32编写FDC1004寄存器的问题

Question

我正在尝试使用连接到freeRTOS中的ESP32的FDC1004读取一些专用传感器。我在写16位FDC1004寄存器时遇到问题。我编写了一个测试代码，用于读取ID和写入配置寄存器。读取任务很好，我可以正确读取FDC1004（0x1004）的ID，但是当我尝试写入寄存器时，我只能正确读取8个LSB。这是我的i2c函数：

esp_err_t I2C_write(i2c_port_t i2c_num, uint8_t slave_address, uint8_t data_address, uint8_t *data_wr ,size_t size)
{

    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (slave_address << 1) | WRITE_BIT, ACK_CHECK_EN);
    i2c_master_write_byte(cmd, data_address, ACK_CHECK_EN);
    i2c_master_write(cmd, data_wr, size, ACK_CHECK_EN);
    //i2c_master_write(cmd, data_addres, 1, ACK_CHECK_EN);

    //i2c_master_write(cmd, data_wr, size, ACK_CHECK_EN);

    //i2c_master_write_byte(cmd, data_wr + size - 1, ACK_CHECK_EN);

    i2c_master_stop(cmd);
    esp_err_t ret = i2c_master_cmd_begin(i2c_num, cmd, 1000/portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);
    return ret;
}

esp_err_t I2C_read(i2c_port_t i2c_num, uint8_t slave_address, uint8_t *data_addres, uint8_t *data_rd , size_t size){
    if (size == 0) {
        return ESP_OK;
    }
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (slave_address << 1) | WRITE_BIT, ACK_CHECK_EN);
    i2c_master_write(cmd, data_addres, size, ACK_CHECK_EN);
    i2c_master_stop(cmd);
    esp_err_t ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);

    cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (slave_address << 1) | READ_BIT, ACK_CHECK_EN);
    if (size > 1) {
        i2c_master_read(cmd, data_rd, size - 1, ACK_VAL);
    }
    i2c_master_read_byte(cmd, data_rd + size - 1, NACK_VAL);
    i2c_master_stop(cmd);
    ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);
    return ret;
}

void FDC1004_writeReg(i2c_port_t i2c_num, uint8_t reg_address, uint16_t data){
    uint8_t tx_buff[2];
    tx_buff[0] = data >> 8;
    tx_buff[1] = data & 0x00FF;

    ESP_ERROR_CHECK(I2C_write( i2c_num, FDC_ADDR, reg_address, tx_buff, 2));
    vTaskDelay(20 / portTICK_PERIOD_MS);
}

uint16_t FDC01004_readReg(i2c_port_t i2c_num, uint8_t reg_address){
    uint8_t read_buff[2];
    uint16_t data;

    ESP_ERROR_CHECK(I2C_read( i2c_num, FDC_ADDR, &reg_address, read_buff, 2));

    data = ((uint16_t)(read_buff[0] << 8) | read_buff[1]);
    return data;
}

[当我尝试分别在寄存器0x08、0x09、0x0A和0x0B中写入0x10C0、0x30C0、0x50C0、0x70C0时，结果分别是：0xFFC0、0xFFC0、0xFFC0和0xFFC0。

希望您能帮助我。

问候

Answer 1

最后，在对代码进行一些测试之后，我将读取功能更改为如下：

esp_err_t I2C_read(i2c_port_t i2c_num, uint8_t slave_address, uint8_t data_addres, uint8_t *data_rd , size_t size){
if (size == 0) {
    return ESP_OK;
}
i2c_cmd_handle_t cmd = i2c_cmd_link_create();
i2c_master_start(cmd);
i2c_master_write_byte(cmd, (slave_address << 1) | WRITE_BIT, ACK_CHECK_EN);
i2c_master_write_byte(cmd, data_addres, ACK_CHECK_EN);
i2c_master_stop(cmd);
esp_err_t ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
i2c_cmd_link_delete(cmd);

cmd = i2c_cmd_link_create();
i2c_master_start(cmd);
i2c_master_write_byte(cmd, (slave_address << 1) | READ_BIT, ACK_CHECK_EN);
if (size > 1) {
    i2c_master_read(cmd, data_rd, size - 1, ACK_VAL);
}
i2c_master_read_byte(cmd, data_rd + size - 1, NACK_VAL);
i2c_master_stop(cmd);
ret = i2c_master_cmd_begin(i2c_num, cmd, 1000 / portTICK_RATE_MS);
i2c_cmd_link_delete(cmd);
return ret;
}

读取功能中的错误之处在于，它使对reg地址的写操作的大小增加了一倍，而只需要一次。这种方式对我有用。