Running nRF52840 on custom board with the ble_app_uart

[Bar1]

Hi All,

I built a custom board that mounts a nrf52840 chip and I followed the schematic N 5 of the datasheet.

I also have 2 evaluation boards nrf52840 EVB "PCA10056", with which I have tested the various applications in "nRF5_SDK_15.1.0_a8c0c4d" including the ble_app_uart.
I tested this application using "Segger Embedded studio for ARM 3.40" and it worked great.

I was able to send data via UART (coming from another board) to nrf52840 EVB_1, send them over BLE to the other nrf52840 EVB_2 and print the data on terminal.

At this point I would liked to test this application on the custom board using a "SEGGER J-Link Base" and through the Segger Embedded studio, I tried to program the custom board and the download was successful, in debug mode it seems running normally, but I can't see any advertising instead with the same app running on the nrf 52840 EVBoard I can see the Bluetooth "Nordic_UART".

The idea was to compare the behaviour of the 2 boards in debug mode and find the problem through some breakpoints.

The problem is that using the breakpoints the program goes to NRF_BREAKPOINT_COND; "both in the case of the evaluation and in the case of the custom board.

I state that from the original code of "nRF5_SDK_15.1.0_a8c0c4d" I only changed the clock in order to use the internal RC oscillator (in the schematic that I used to realize the custom I did not put the LF clock optional)

#ifndef NRF_SDH_CLOCK_LF_SRC
#define NRF_SDH_CLOCK_LF_SRC 0
#endif

#ifndef NRF_SDH_CLOCK_LF_RC_CTIV
#define NRF_SDH_CLOCK_LF_RC_CTIV 16
#endif

#ifndef NRF_SDH_CLOCK_LF_RC_TEMP_CTIV
#define NRF_SDH_CLOCK_LF_RC_TEMP_CTIV 2
#endif

#ifndef NRF_SDH_CLOCK_LF_ACCURACY
#define NRF_SDH_CLOCK_LF_ACCURACY 1
#endif

in sdk_config.h.

Is there anybody who could help me?

Thanks

[Jørgen Holmefjord]

Hi,

You cannot debug applications using breakpoints and stepping when you are using a softdevice. Hitting a breakpoint will halt the CPU and prevent the softdevice from handling timing critical events. You can set breakpoints in the code to see if the application runs to this point, but you cannot continue running from this point. Single stepping can be done until you meet a softdevice call, then the application will jump to the error handler and hit the NRF_BREAKPOINT_COND.

I recommend that you have a look at this post and this video, showing how to debug the application and read out any error codes that occur.

Best regards,
Jørgen

[Jørgen Holmefjord]

Yes, you should be able to run the example with that change. If you are not seeing any errors, it could indicate that you have some hardware issue.

[Bar1]

Hi Jørgen,

Is it possible that the radio does not work because I used the Schematic 5 version 0.5?

Just now I saw that in 0.5.1 something has changed:

https://devzone.nordicsemi.com/f/nordic-q-a/29213/nrf52840-q1aabb-ble-advertising-problem/116181#116181

or could be related at the difference between the chip on the custom board "nrf52840 QIAACO 1815AM" and the chip on the Evaluation Board "nrf52840 QIAABB 1743AA"?