Unable to flash custom nRF5340 board with nRF5340DK

RE: Unable to flash custom nRF5340 board with nRF5340DK

Matt M — Fri, 21 Jul 2023 20:25:10 GMT

Hi Runar,

We revisited the steps you outlined and were successful with flashing our board. I am unsure where we went wrong previously, but the following specific sequence of steps works for us every time:

Start with the nRF5340DK board unpowered and unconnected to anything.
Set the nRF POWER SOURCE switch on the DK board to USB.
Connect our custom board to the Debug Out connection.
Power on our custom board.
Plug a USB cable into nRF USB connection and set the DK's POWER switch to ON.
Plug a USB cable into the J2 USB connector.

From there the DK board was recognized as a JTAG device, and we were able to erase and flash our board as normal.

Thanks for your help!

RE: Unable to flash custom nRF5340 board with nRF5340DK

Matt M — Thu, 06 Jul 2023 15:50:28 GMT

Hi Runar,

Thank you for your response. We tried the steps you outlined, but were still unsuccessful. We will be trying a level translator next.

RE: Unable to flash custom nRF5340 board with nRF5340DK

runsiv — Fri, 30 Jun 2023 11:00:07 GMT

Hi,

The problem is that the custom PCB is running 1.8V while the DK is running 3,3V.

What you can try to do is the following:

Connect a usb to both J2 and NRF_USB
Switch from "VDD POWER" to "USB SOURCE" on SW9
Power up the DK
Enjoy 1.8V debugging

If not I would put a level shifter between the DK and the custom PCB

Regards

Runar