How to resolve nRF52832 encountering disconnect reason 0x22 LMP Response Timeout when based S132 SoftDevice v6.1.0 ?

[tianfei00]

Dear all,

        I modified the example "ble_app_uart" based nRF5_SDK_15.2.0_9412b96 and S132 SoftDevice v6.1.0 to do some tests . But now I encounter the disconnect reason 0x22 LMP Response Timeout error when andriod device established connection with nRF52832 about 40 seconds. I do not know how to resovle this problem at all.

       I also search this 0x22 LMP Response Timeout error in the devzone, but I do not find any correct and effective methods until now.

      I will look forward Nordic's useful help.

      Best regards,

      tianfei00

[Vidar Berg]

Hi, 

Did you keep the gatt_init() function responsible for handling MTU and DLE requests? I would expect this error if you have removed it. 

Best regards,

Vidar

[tianfei00]

Hi Vidar Berg,

Firstly I used the example "ble_app_uart" based nRF5_SDK_15.2.0_9412b96.

Secondly, in my project the code realated to gatt_init() as following:

/**@brief Function for handling events from the GATT library. */
void gatt_evt_handler(nrf_ble_gatt_t * p_gatt, nrf_ble_gatt_evt_t const * p_evt)
{
    if ((m_conn_handle == p_evt->conn_handle) && (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED))
    {
        m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
        NRF_LOG_INFO("Data len is set to 0x%X(%d)", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
    }
    NRF_LOG_DEBUG("ATT MTU exchange completed. central 0x%x peripheral 0x%x",
                  p_gatt->att_mtu_desired_central,
                  p_gatt->att_mtu_desired_periph);
}


/**@brief Function for initializing the GATT library. */
void gatt_init(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
}

As you mentioned before, but the  gatt_init() has already existed in my code. How can I resolve this error.

Many thanks for you.

Best regards,

 tianfei00

[Vidar Berg]

Hi,

Can you upload the project or post the changes you made so I can test it here? Alternatively, if you have access to a Bluetooth sniffer, upload a trace showing the packet exchange from connection to disconnect.

Best regards,

Vidar 

[tianfei00]

Hi, 

   The 0x22 BLE_HCI_STATUS_CODE_LMP_RESPONSE_TIMEOUT error which I encountered is not in all the andriod devices but only some of them.

   So whether you have the download address of the Bluetooth sniffer and the detailed user guide of the Bluetooth sniffer to acquire the data which your wanted so you can analysis the reason result in 0x22. Please provide them for me.

   Because your official website is difficlut to visit, especially to download files in China. So if you can provide any other download address for me.

   Thanks a lot.

Best regards,

Tianfei00

[tianfei00]

Hi,

  If any other hardware device will be needed, for example nRF51 Dongle , when  I want to use Bluetooth sniffer ?

But actually I do not have any nRF51 Dongle at all. So how can I resolve this error?

Best regards,

Tianfei00

[Vidar Berg]

Hi, 

You can find the sniffer downloads here: https://www.nordicsemi.com/Software-and-Tools/Development-Tools/nRF-Sniffer/Download#infotabs. But you will need to have another DK/Dongle to sniff with. 

The fact that it works with some android phones make me suspect that this is still related to MTU (some android phones does not support longer MTUs). Do you get the "Data len is set to <bytes>" message in your debug log? 

Edit: have you changed anything in main.c->ble_evt_handler()?

[tianfei00]

Hi,

   Follow your advice, 0x22 BLE_HCI_STATUS_CODE_LMP_RESPONSE_TIMEOUT error has been resolved when I modified the NRF_SDH_BLE_GATT_MAX_MTU_SIZE as 23.

Thanks a lot.

Best regards,

Tianfei00