Custom nRF52840 board works in debug mode only.

[xcess]

Hi,

This is my first post and I'm not an expert of Zephyr & nRFs. I have a custom nRF52840 board which I am able to program and debug using nRF52840 DK. I am using Blinky example and is able to see GPIO turning HIGH only under following prj.conf:

CONFIG_GPIO=y
CONFIG_BOARD_ENABLE_DCDC=n
CONFIG_BOARD_ENABLE_DCDC_HV=n
CONFIG_BOOTLOADER_MCUBOOT=y

If I set MCUBOOT=n then I am not able to debug my program. It goes into some infinite loop and never comes into the main. However, when I enable it then I am able to debug my program and able to blink.

But, this only works in debug mode and I have disabled DCDC in prj.conf.

I am unable to execute my program in normal mode.

I have powered the custom board through VDDH from VDD of my nRF52840 DK. I get 3V on VDDH and 1.6V on VDD of my custom board.

I saw somewhere that they were able to solve by using "nrf_power_dcdcen_set(NRF_POWER, false)"? Where can I implement this? Will it help?

Thanks for your help & guidance.

Regards

[Simonr]

Hi

Have you had anyone take a look at your custom board design files and schematics to make sure that it looks okay in terms of antenna tuning? By "still not able to run Bluetooth/ Beacon sample app", I assume you're able to flash it onto the board, but that you don't see any Bluetooth activity on a central device?

From the nRF Connect SDK it should take care of flashing the Bluetooth controller onto the application as well. What app are you trying to run, and have you made a custom board file that fits your design? Please check out the documentation for more info on that.

Best regards,

Simon

[xcess]

Thanks for replying and have got that PCB according to reference design as far as antenna matching is concerned and copied antenna of nRF52840 DK. Yes, I am able to flash the app but on central I don't see advertisement of peripheral. I am flashing Zephyr/samples/Bluetooth/Beacon app on my custom board and used the "nrf52840dk_nrf52840" board provided in the app. I haven't created my own board yet.

Regards

[Simonr]

If you haven't created your own board file based on your design, there might be differences in what pins do and if the application starts up correctly. Could you upload the schematics of your custom board so we could take a look and possibly give you some pointers? Things I suspect include, the external HF crystal isn't mounted or is loaded incorrectly, or some missing vital components. Also we'll get an idea of what you need to change in your custom board file.

Best regards,

Simon