nRF52840 DTM Can not communicate with my custom device.

[paul0208]

Hi,

My custom board use nrf52840.
I first tested uart function by examples/peripheral/uart/*. It is good.
My board's uart ports are P1.9 for TX, P0.12 for RX.

And then, I modified the nRF5_SDK_17.1.0_ddde560\examples\dtm\direct_test_mode/main.c
But, it is not working with nRF Connect for desktop/Direct Test Mode.
I find " Can not communicate with my custom device." error.

And, I modify TX/RX port in main.c of dtm example to as follow

P0.05	RTS
P0.06	TXD
P0.07	CTS
P0.08	RXD

And compile and upload to nrf52840 DK board.
But, Direct test Mode appl do upgrade nrf52840 DK board firmware to some binary(maybe pre-compiled version by Nordic)
And DTM test is success by your binary.

Wha problem in my product?

BR
Paul

[paul0208]

For DTM, do I have to assign RTS/CTS pin?

[Jared]

Hi,

But, Direct test Mode appl do upgrade nrf52840 DK board firmware to some binary(maybe pre-compiled version by Nordic)
And DTM test is success by your binary.

What do you mean, it works when using the pre compiled binaries on your custom board but it doesn't work when you use your modified code?

paul0208 said:

For DTM, do I have to assign RTS/CTS pin?

Here:

regards

Jared

[Jared]

Hi,

paul0208 said:

I want to do DTM test  for my custom board by nRF Connect DTM directly. not thru DK board.

This is not supported, you either have to use a DK or a Anritsu as a production tester. This is described in the app note I shared earlier:

paul0208 said:

My board use 1.8V. Can I program this board by nRF52840 DK or nRF52832 DK ?

From the documentation:

Note: The voltage supported by external debugging/programming is VDD voltage. Normally, this is 3 V when running from USB, but if the onboard nRF52840 SoC is supplied from either USB or Li-Ion, the nRF power source switch (SW9) is in either Li-Po or USB position, and VDD can be set by the nRF52840 firmware. Make sure the voltage level of the external board matches the VDD of the nRF52840 DK.

regards

Jared 

[paul0208]

Hi,

DUT has UART interface connected to PC or Anritus as Fig 2 you attached.
And dtm example should be programed into DUT after modifying UART configuration.

This dtm example is not interworking with nRF connect DTM directly?
Computer in Fig 2 is not nRF connect DTM?

BR
Paul

[Jared]

Paul,

The computer is indeed running nRF Connect DTM but you still need either a Anritsu or a DK as a tester. I think it would be good if you could share a picture or a sketch that shows how you have setup the test, it would clarify any confusions. 

Thank you,

regards

Jared 

[paul0208]

Hi
Please find my configuration for certification.
IF DUT is replaced with DK, DTM test result is OK

BR
Paul

[Jared]

Hi,

I see so you're setup is basically this:

I misunderstood you, I didn't understand that you had already had a spectrum analyzer for testing, I thought that you wanted to use the DK as a tester, but I now understand that you have a spectrum analyzer for testing. What kind of spectrum analyzer is it? The nRF Connect DTM sw is made to be used with a development kit as a tester, if you're using a spectrum analyzer such as a Anritsu then you have to use the scripts that are made by the manufacturer of that spectrum analyzer,

regards

Jared 

[paul0208]

Hi,

The issue turned out to be a hardware problem without any apparent cause.

My H/W engineer did equip 32MHz Xtal with wrong direction.
The direct test mode example is working on my custom board now.

Please close this ticket.

BR
Paul

[rockerderek]

Hi Jared,

I'm having a similar problem. I'm trying to use SDK 2.3.0 nrf/samples/bluetooth/direct_test_mode with built-in USB on nRF5340 or the UART-to-USB virtual COM port with an FTDI cable that has a TC2030 connector on the end, but that hasn't worked.

The TC2030 connector looks like this on our PCB:

6242.TC2030-MCP-NL.pdf

Based on this document DTM for DUT

Our UART_DBG_TX pin is P0.28 and the UART_DBG_RX pin is P0.27. Do I need to edit the nrf5340dk_nrf5340_cpunet-pinctrl.dtsi file like so?

And do I add CONFIG_DTM_USB=y to my prj.conf file without adding any files like zephyr/drivers/usbc.h or other code to use DTM on my custom board via USB? I also added CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y to the prj.conf file since we don't have an external 32KHz oscillator between X1 and X2. Is there anything else I need to do to make the nRF Connect DTM app on my Windows 10 PC work with my custom board?