Fatal Error after sending notification

[Toran613]

Hey Guys,
currently, I am working on my masterthesis. I have to develop an mobile application which comminicates with the nordic board via BLE. I know that there is an existing application from nordic but I had to implement some extra features. The example I use is the ble_peripheral_uart example. According to measure my traffic I am using Docklight. 

My issue is that always when I try to send a notification with docklight to my application (Notification is enabled) my embedded studio crashes and I get a fatal error. Writing messages from the app to the board is possible. I can see this on docklight. 

The confusing point is that when I started to write messages and send notifications it worked. But one day I tried it again and this error appeared, which is really annoying because I haven´t changed a single line of C-Code from the example. I tried to run a new version from the code, I tried to use different versions from my android studios code, I ran the code on several computers I changed the eval board, I changed the UART-Module I am using, I reinstalled the software - nothing worked.

I noticed that it is possible to send notification as long as I send only one letter or number. When I send more letters or numbers or add \n my code crashes. Obviously, it is a memory issue but I don´t understand why it worked at the beginning. 

Can you give my some advices?

Kind Regards,
Thomas

[Einar Thorsrud]

Hi Thomas,

My issue is that always when I try to send a notification with docklight to my application (Notification is enabled) my embedded studio crashes and I get a fatal error.

Is this Segger Embedded Studio(?) that has a fatal error and crashes, or is it that you see a fatal error in the log from the nRF? If it is the latter, then this is likely from an APP_ERROR_CHECK. In that case, testing a debug build (select "Debug" from the build configuration dropdown menu) will give you more information. With this you should see file name, line number and error code, and that will give us much more to go on.

[Toran613]

Yes, I am using Embedded Studio. These are the error codes I get when I try to send a notification. But I have to add, that I made a mistake in my explanation. I can send more than one sign as long as I don´t add "\n". The point is that I need \n because without it, I have to send several packages until my app gets the packages. 
Is it possible that it is something like a cache problem? Because no matter on which device I ran my C-Code, first it worked and after a few trys I got this error.

[Toran613]

this is not what you needed, I guess

[Einar Thorsrud]

Hi,

This is not the relevant log. This is from programming the device, and what we are after is the log from the device, which where there are printouts from the error handler. And the code in your snippet is from the error handler, and that runs because of the error. The relevant log is from your previous screenshot, specifically in the left par of it, where you see the debug log printed by your application running in the nRF. This log contains all information we need to start looking into this, when combined with the file it points to (probably your main.c, but could also be something else).

I strongly suggest that you spend time understanding the error handling in the nrF5 SDK by the link in my previous post. This will surly save you time in the long run.

[Toran613]

<info> app_timer: RTC: initialized.
<info> app: Debug logging for UART over RTT started.
<info> app: Connected
<info> app: Data len is set to 0xF4(244)
<error> app: ERROR 4 [NRF_ERROR_NO_MEM] at C:\Users\loratho\Desktop\Projektordner_Thomas_Loran\Masterthesis\BLEtoUART\Nordic\nRF5_SDK_BLEtoUART\examples\ble_peripheral\ble_app_uart\main.c:581
PC at: 0x0002F8E3
<error> app: End of error report

Thank you for the Link. I am read it and try to understand it. Here is the left part of the screen, you metioned

[Einar Thorsrud]

Good. Did you also check what happens around line 581 in your main.c file?

[Toran613]

void uart_event_handle(app_uart_evt_t * p_event)
{
    static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
    static uint8_t index = 0;
    uint32_t       err_code;

    switch (p_event->evt_type)
    {
        case APP_UART_DATA_READY:
            UNUSED_VARIABLE(app_uart_get(&data_array[index]));
            index++;
            rx_uart_data = data_array[index];
            if (rx_uart_data == 'h')
            {
                 bsp_board_led_on(CONNECTED_LED_3);
                 nrf_delay_ms(1000);
                 bsp_board_led_off(CONNECTED_LED_3);
            }

            if ((data_array[index - 1] == '\n') ||
                (data_array[index - 1] == '\r') ||
                (index >= m_ble_nus_max_data_len))
            {
                if (index > 1)
                {
                    NRF_LOG_DEBUG("Ready to send data over BLE NUS");
                    NRF_LOG_HEXDUMP_DEBUG(data_array, index);

                    do
                    {
                        uint16_t length = (uint16_t)index;
                        err_code = ble_nus_data_send(&m_nus, data_array, &length, m_conn_handle);
                        if ((err_code != NRF_ERROR_INVALID_STATE) &&
                            (err_code != NRF_ERROR_RESOURCES) &&
                            (err_code != NRF_ERROR_NOT_FOUND))
                        {
                            APP_ERROR_CHECK(err_code);
                        }
                    } while (err_code == NRF_ERROR_RESOURCES);
                }

                index = 0;
            }
            break;

        case APP_UART_COMMUNICATION_ERROR:
            APP_ERROR_HANDLER(p_event->data.error_communication);
            break;

        case APP_UART_FIFO_ERROR:
            APP_ERROR_HANDLER(p_event->data.error_code);
            break;

        default:
            break;
    }
}

its a switch case. Seems like I get in the wrong state of my uart_event_handler. I get in the state APP_UART_COMMUNICATION_ERROR The error also shows that I have a memory issue.

[Einar Thorsrud]

Good, you are getting closer. Just so I know as well Which line in this code snippet represents line 581?