nRF21540 custom board DTM (Direct Test Mode) Failed

[Kevin Choi]

Hello,

I am currently working on a project using a custom board with nRF52840 + nRF21540. I am trying to measure wireless performance using Direct Test Mode (DTM), but the test fails in the Direct Test Mode desktop application, preventing the test from running. Additionally, the nRF21540 is not functioning, and when checking the PDN pin, there is no response.

Below are the steps I followed:

• Imported the Direct Test Mode example from nRF Connect SDK, using nRF21540DK as the board target and modified the pin configurations accordingly.
• Connected to the DTM program in nRF Connect for Desktop.
• When testing Transmitter / Constant Carrier, I encountered the following "command failed" log messages.
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Is there a solution to resolve this issue?

Thank you.

[Asbjørn]

Hello Kevin,

I only have the nRF21540-DK available here, but I was able to build and run the DTM service in nrf connect for desktop with it. 

A couple of things to check, you have a custom board, does it have an external 32k crystal or have you configured the DTM to use the RCOSC?

Have you changed the pin functionality of any of the GPIOs related to the UART interface or have you mapped up your pin selection to the nRF connect expectation? The command fail is usually related to either of those two changes.

Do you have a USB to UART translator on your board?

Best regards

Asbjørn