nRF Connect Direct Test Mode application doesn't work with nRF5340

[ArthurLai]

I flashed my board with DTM image, assign P0.20 for TX and P022 for RX.  Most of the times the DTM application can't communicate with the nRF5340, maybe 1 out of 20 times, it sends the command to start the test.  Out of those successful connected, 1 out of 10 times actually able to setup the test.

Failed to connect most of the time

Failed to setup the test if connected

I sniffed the UART line and found the Application doesn't send the commands correctly most of the time. When I click start test button, the App only send "0000"

Maybe 1 out of 100, I got lucky and the App setup the test correctly

Is the version v.1.1.7 not for nRF5340? Or there is another version/application for nRF5340?

Thanks.

[helsing]

Hi Arthur,

Thank you for the update.

What is does the physical connection to your board look like? Have you ruled out faulty lines? Are you using the nRF5340 DK? 

Best regards,

Håkon

[ArthurLai]

I found a work around to make the nRF5340 eval board DTM FW working with the nRF Connect.

I removed the debug message in the DTM FW : all printk like like this:

        printk("Sending 0x%04X DTM command\n", dtm_cmd);

The nRF Connect get all the UART messages from all 3 VCOMs, one port is for the debug message and nRF Connect doesn't recognize this message. After removing those printk lines, there is no more debug message.

Still, the issue is in nRF Connect, it should allow the user select only one port.

Thanks.

[helsing]

Hi Arthur,

Thank you very much for this update. I have forwarded these findings to our team. Let us know if the solution is causing you any limitations as you are moving forward.

Best regards,

Håkon