Programming custom NRF52832 board using SWD interface

[DineshB]

Hello NRF,

I have a custom board with NRF52832, and exposed the SWDIO, SWDCLK, GND, VDD, RESET pins for programming the board through the NRF52-DK board.

I started with a sample peripheral_uart, connected the NRF52-DK board to my PC, and managed to BUILD and RUN the sample application.

I verified that the app is working, by connecting to the UART service advertised by this app (on NRF52-DK) through another device that has NRF-TOOLBOX and used the UART service to query the NRF UART (NRF52-DK board) and managed to read write and verified the same over the console.

Now, I want to program my custom board, instead of the NRF52-DK board. Based on some suggestions on this site, I connected the

NRF52-DK        CUSTOM_BOARD

SWDIO             SWDIO

SWDCLK          SWDCLK

GND-DET         GND

VTG                 VDD/3V3

I then powered my board and then tried the BUILD and RUN option on the SEGGER.

It seems like my custom board is not getting programmed.

I would like to know : 

1. Do I have to first program a bootloader on to my custom board. If so, please advise a boot loader that I can download from your site (if possible) and the steps to program the same on to my custom board.

2. How to program the compiled/build binary/hex files on to my custom card? Just BUILD and RUN would download the binary on to the connected custom board, instead of the NRF52-DK board? (because my custom board is connected through the SWD port and GND detected?) If BUILD and RUN wouldn't work, where can I find the compiled binary or hex file where I can program the same on to the custom board , perhaps by using command line nrfjprog tool???

3. I believe the peripheral_uart has it's pin definitions, for the RX, TX, LEDs etc. Since my custom board pin assignments might be different from that of the NRF52-DK, where can I find these definitions, so I can go map the pins?

All I need is to demonstrate this peripheral_uart app on my custom nrf52832 board, where I will connect a serial port on to its RX/TX to a putty terminal (on my pc) and then able to rx/tx data back and forth with the other connected device (NRF toolbox -> UART).

I appreciate your help in this regard.

regards,

Dinesh.

[Simonr]

Hi

DineshB said:

So, on the Sparkfun dev kit, nothing is connected, all GPIOs are open, only the rx/tx are connected to a serial2uart cable. Their definitions are, P0.27 -> TX and P0.26 -> RX

 I think this is the reason, the Nordic Development Kits use P0.06 and P0.08 for UART by default for instance. It is generally important to select the correct board files for the board you're using. If your custom board is a replica of the Sparkfun board then selecting the sparkfun board should be fine, but we generally suggest creating board files for custom boards.

Best regards,

Simon

[DineshB]

Hello Simon,

Are you suggesting, if I go and remap the RX/TX pins from P0.06/P0.08 to P0.27/P0.26, then perhaps I should be able to program the cards, both Sparkfun dev kit and the custom board, through the NRF52_DK board selection?

Also, these are just pin assignments, and if nothing is connected to the rx/tx pins, how would the program know if these pin assignments are wrong? After all, its telling the processor to use 6 and 8, instead of 26 and 27. Is there some form of a communication between the nrf chip and the debug chip, through SWD interface, that will emulate JTAG and make sure the serial port is working (so you would need the correct pin mapping)?

regards,

Dinesh.