RE: Requirements for re-flashing firmware on nRF52840

Simonr — Wed, 09 Jun 2021 12:11:54 GMT

Hi Griffin

1. I think you have misunderstood somewhat. You won't need a bootloader on your custom board SoCs if you have a debugger (or nRF52 DK) available and the SWD pins are available on your custom board(s). Connecting the J-Link debugger to the custom boards' SWD pins while powering the board should let you flash program and debug these devices as well. No bootloader needed. A bootloader will be necessary if you don't have access to the debug interface on the board or you don't have a debugger available.

2. You will need access to the SWDIO and SWDCLK pins as well as VDD and GND to connect to a debugger/DK.

3. Yes, you can use an nRF52840 DK to flash and debug custom board. Please see section 8.10 Debug output in the nRF52840 DK user guide for details.

4. If you flash a bootloader supporting USB firmware updates onto your board, then yes. Here is a list of the DFU bootloader examples we provide.

Best regards,

Simon