How to upload firmware on custom board with brand new nRF52840

[Salvo]

Hi,

i'm new on using nRF5 modules and i have some question about how to program the nRF52840 on a custom board, so with a completely new chip.

Reading the schematic of the nRF52840 Dongle i understand that the device is flashed directly connected to the USB of the PC, but reading a forum and information on the infoCenter, i understand that it is possible to becouse the dongle arrives with a pre-programmed bootloader, that allows flashing firmware via USB.

Now I'm asking: if I have the necessity to make a custom board with a brand new nRF52840, what do I have to take care about during the schematic design in terms of connector and pins necessary to flash the device? I need the SW interface? If yes, I will have to use another external programmer until I will flash a bootloader that enables for the USB programming mode, it is?

Thanks in advance.

Salvo.

[Matevz B]

Hello!

I have had the same quesiton. We included 10 pin jtag debug port on our custom PCB for programming the nRF52840. I program it using the nRF52DK.

I use this cable: www.segger.com/.../

The wiring for programming is per this thread: https://devzone.nordicsemi.com/f/nordic-q-a/14058/external-programming-using-nrf52-dk

I disconnected the connection to P20 VDD pin since our board has external power supply.

Hope this helps.

Best regards,
Matevz