I2C Problem initializing on pin33 and pin36

[kacie_23]

Hello,

I have a problem initialising the master i2c on my ESP32wroom32

I have connected I2C lines on Pin33 and Pin36 (I2C_Data, I2C_Clock respectively).
These pins seem to be connected to GPIO8, and GPIO23.

GPIO8 seem to be the problem, since this pin has funciton1 as SD_DATA1, and function2 as GPIO8.

If I remove the GPIO8, and just select some unused GPIO, the initialisation works, but without any communication of course.

Whenever I introduce the GPIO8 in the initialising code, the CPU panics.
I assume that the I2C_MODE_MASTER is either 0 or 1, and I can freely choose this number.
I2C_DATA_GpioPortNr = GPIO_NUM_8
I2C_CLOCK_GpioPortNr= GPIO_NUM_23

trace.txt

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Code: Select all

esp_err_t sensorClass::i2c_master_init(void)
{
    esp_err_t lv_errorVal;

    i2c_config_t conf;
    conf.mode = I2C_MODE_MASTER;
    conf.sda_io_num = I2C_DATA_GpioPortNr;
    conf.sda_pullup_en = GPIO_PULLUP_ENABLE;
    conf.scl_io_num = I2C_CLOCK_GpioPortNr;
    conf.scl_pullup_en = GPIO_PULLUP_ENABLE;
    conf.master.clk_speed = I2C_frequency;
        
    lv_errorVal = i2c_param_config(I2C_Master_Port, &conf);
    if (lv_errorVal != 0) 
        printf("I2C init - %s : Parmeter config error\n", esp_err_to_name(gv_errVal)); 

    lv_errorVal = i2c_driver_install(I2C_Master_Port, conf.mode, I2C_MASTER_RX_BUF_DISABLE,I2C_MASTER_TX_BUF_DISABLE, 0);
    if (lv_errorVal != 0) 
        printf("I2C init - %s : Driver install error\n", esp_err_to_name(gv_errVal)); 
    
    return lv_errorVal;
}

[ESP_Sprite]

GPIO8 is used by the flash the ESP32 is running your program from. Don't use that.

[WiFive]

In fact you should avoid all Flash pins 6-11

[kacie_23]

The datasheet for the ESP32 is different from the datasheet ESP32wroom32, making the answer quite stupid since it is only a result of confusion.

When establishing the GPIO_NUM_xx for the entry of the I2C pin numbers it was corrected properly when looking at the PIN-setup for the wroom module.

Code: Select all

//Correct entry for the master init of I2C - at pin33 and pin36
initI2C.i2c_master_init(I2C_NUM_0,GPIO_NUM_21,GPIO_NUM_22);