Program stuck inside log_init

[kian79]

Hi,

I am developing my own PCB board and application based on a nrf52832 module (MDBT42Q). To test the board, I tried downloading an example program onto the module, in this case, I use the ble_app_uart example. I am using a nrf52 Dk to download the program to the module.  I have external 32K crystal and 12pF capacitors connected to the module, and also a 10uH and 15nH inductor in series with a 1uF to ground (DC-DC mode).

The program compiles and downloads successfully, but its stuck at the log_init function when I try to debug. When I pause the debugger, it get stucked inside the function static void log_skip(void) and at the line "rd_idx       += (p_header->base.pushed.len + p_header->base.pushed.offset);"

I have no idea what is wrong.  Downloading the same program into the NRF52 DK  itself gives no problems and it doesn't hang.

I noticed that I do not have a 10K pull up resistor on the RESET pin. Now the reset pin is just floating. Could that be the cause?

Anyone can help?

Thanks in advance!

Update: 10/4

I tried uploading other programs and some of them works. For example, ble_app_alert_notification, ble_beacon, ble_blinky, ble_app_template, ble_app_hrs works! Just not the ble_app_uart example which I need.

[Jørgen Holmefjord]

Hi,

Does the application work if you remove the log_init and logging functions from the code, or does it stop somewhere else then? Which SDK version are you testing? Have you made any changes to the example, or is it a clean version from the SDK?

Best regards,
Jørgen

[kian79]

Hi Jorgen,

I am using SDK_14.2.0. I just did a clean install of the SDK so the examples are unmodified. I have soft device S132 loaded onto the module.

I had never had any problems downloading programs to an external nrf52832 in the past when I designed my own PCBs. But this is the first time I am using a module. I am very sure my connection are correct. I have VDD, VTG, SWDIO, SWDCLK on P20 connected to my module's VCC, SWDIO, SWDCLK. And I have the GND pin on the NRF52 DK connected to the GND of my module.

With the ble_app_uart example, it stucked inside this while loop of the log_skip function:

    // Skip any string that is pushed to the circular buffer.
    while (p_header->base.generic.type == HEADER_TYPE_PUSHED)
    {
        rd_idx       += PUSHED_HEADER_SIZE;
        rd_idx       += (p_header->base.pushed.len + p_header->base.pushed.offset);
        p_header = (nrf_log_header_t *)&m_log_data.buffer[rd_idx & mask];
    }

I tried to remove the log_init and commented out the call to NRF_LOG_INFO in the main function. Then I also uncheck "NRF_LOG_BACKEND_RTT_ENABLED" and "NRF_LOG_ENABLED" in sdk_config;h.

With logging disabled, I go into a NRF_BREAKPOINT_COND in app_error_weak.c

I tired with another (same) spare module and its giving the same problem.

Interestingly a few examples like ble_app_blinky and ble_app_beacon works! But not the ble_app_uart which I need!

[Jørgen Holmefjord]

Could you check if there is any error codes returned when you end up in NRF_BREAKPOINT_COND/app_error_weak.c, as described in this post?

[kian79]

Hi Jorgen,

The error code is 0x00004001

If I comment out uart_init, the program actually manages to debug and run. I can scan and see it advertising from nrf connect app..

Now I am sure uart_init is causing the problem. But why?