Direct Test Mode (DTM) Response

[Sami]

I would like to use the direct test mode (DTM) to test my own hardware with Rohde & Schwartz CBT. I have managed to create a simple test case using nRF52 DK and the example in nRF5 SDK. I managed to modify the UART configuration according my own hardware. However, the documentation does not mention anything about what kind of response is expected. It is also missing examples what kind of commands should be sent.

According to the documentation there are four supported commands (setup, transmitter and receiver tests and end). When I send command "TEST SETUP" to the chip, the response is always "0101010001". However, I was expecting something more readable.

As a consequence, I think I am not sending correct data or I cannot interpret the output. Does anyone have any examples what kind of commands should be sent and what kind of output should be expected?

[Kenneth]

The commands and responses are described in BT core spec v5.2 vol 6 part F, chapter 2 (for instance page 3194):

https://www.bluetooth.com/specifications/bluetooth-core-specification/ 

[Sami]

According to the specification I should send command "LE_Transmitter_Test" and the DUT should sent back "LE_Status".

However, I am not sure command "LE_Transmitter_Test" should be sent to the DUT and what kind of response should be expected. If I send string "LE_Transmitter_Test" to the UART port, the response is still the same.

How the commands should be sent? Is there some kind of data format?

[Kenneth]

You may find the application note using DTM in production testing useful:
https://infocenter.nordicsemi.com/topic/struct_appnotes/struct/appnotes_nan34.html

Best regards,
Kenneth

[Kenneth]

Have you made any progress? You may also find the documentation for DTM useful:
https://infocenter.nordicsemi.com/topic/sdk_nrf5_v16.0.0/ble_sdk_app_dtm_serial.html

You may need to edit the pca10040.h (if you are using nRF52832) to fit the pins you want to use:

#define RX_PIN_NUMBER 8
#define TX_PIN_NUMBER 6
#define CTS_PIN_NUMBER 7
#define RTS_PIN_NUMBER 5

Make sure to power cycle the board after programming, this should ensure that the SEGGER -jlink does not take control over the UART pins above.

The tester need to have common ground with the DK, and voltage level should be ~3V for the UART pins. Adding a 1Mohm pull-up on the RX and TX pin may be a good idea to avoid them floating while not connected to the tester.

Best regards,
Kenneth

[Jimmy Wong]

hi,

I list out some command of the DTM (TX / RX). You can refer to 

https://jimmywongiot.com/2019/09/02/rf-physical-test-on-the-nrf5-series/