Use dtm via two-wire UART on custom BM833A

[RichardHdrd]

Dear Forum,

I have successfully compiled and pretested the direct test mode firmware for SDK_17.0.2.

The UART is shown as /dev/ttyUSB0 in my Ubuntu 20.4 Linux system. Testwise, I also added a printf("Hello world") which I can see when using my com-reader (cutecom, 19200/8N1, /dev/ttyUSB0) and starting the firmware. I then removed the test-"Hello World" again and compiled the firmware and installed it to a BM833A.

I use a UART to USB converter (offering a /dev/ttyUSB0 in my Linux system) for accessing the UART.

Now, I want to use the App "Direct Test Mode v. 2.0.1" from "nRF Connect for Desktop v3.11.0", but:

There is no way to choose a com interface from this app, instead, I only get:

Select Device-->"Connect a "Nordic Development kit" to your computer.

But I want to select a "device that supports 2-wire DTM", which is possible according to that thread:

https://devzone.nordicsemi.com/f/nordic-q-a/81788/dtm-via-nrf-connect-using-a-custom-board

So, what do I need to do to be able to select /dev/ttyUSB0 as 2-wire DTM?

Best regards,

Richard

[JONATHAN LL]

Hi,
When you build and compile the DTM sample you need to change the RX and TX_PIN_NUMBER to the correct ones you are using on your custom HW. 


Regards,
Jonathan

[RichardHdrd]

Hi Jonathan,

Of course I did that - I thought, that was clear when I stated, that I even sent a test message via UART.

But I cannot select the UART, because the App "Direct Test Mode v. 2.0.1" from "nRF Connect for Desktop v3.11.0" doesn't allow to select /dev/ttyUSB0.

If I use the default Rx/Tx settings and the nrfBM833DK, I can select this nordic development kit in the App's dropdown list and it works.

If I instead connect my custom BM833 (with modifiied Rx/Tx rendering working /dev/ttyUSB0) the App's dropdown box is empty!

So, what do I need to do to be able to select /dev/ttyUSB0 as 2-wire DTM?

Best regards,

Richard

[JONATHAN LL]

Hi Richard, 

Sorry for the misunderstanding, I have requested that the developers comment on this issue, and why it is not possible to just select a serial port of choice, but due to Easter holiday you might not get a answer before next week. 

Regards,
Jonathan

[JONATHAN LL]

Tiny update, 

Dev team has been informed and are looking in to add a update to include the option to select any comport not just the DK\debuggers. 

Regards,
Jonathan

[JONATHAN LL]

Hi, 

Pleas update to DTM app v2.0.2 , should be a fix there now, see if it solves your issue. 

Regards,
Jonathan