How to Run DTM on nRF52840 development kit using MT8852B?

[New Guy]

Hi all,

I have a nRF52840 development kit and flashed (I believed it flashed successfully) with direct test mode .hex file from SDK 15.2. What I facing was not able to run any test from MT8852B due to unable to get the unit address from the board. Did anyone tried to run DTM with MT8852B on nRF52840 DK ? Kindly advise

TQ

[Håkon Alseth]

Hi,

 

In order to get DTM running on any bluetooth tester, you would need to use other RXD and TXD pins when using the nRF5x development kit. This is because the UART is by default routed to the SEGGER IC on the devkit, so you will get two UART hosts conflicting the lines.

If you go into the dtm/direct_test_mode/main.c file, you can change the defines for RXD and TXD in function uart_init().

After changing these from the default GPIOs P0.06 and P0.08 (flip the kit over to see which GPIOs are unused), you can connect the chosen GPIOs to the bluetooth testers UART. Remember to use BLE 2-Wire when connecting to the Anritsu.

Kind regards,

Håkon

[New Guy]

hi Hakan,

regarding the Rx & Tx pin, if i only use the J3 usb port as the power source to the nRF52840 chipset, could this good enough to avoid the conflict as you mentioned?? in this case, do i still need to redefine the pin in the main.c file ??

Another thing, i am using the dtm/direct_test_mode_pca10056.hex file instead of the dtm/main.c file as the source for the test. any different between them?? kindly advice if i am using the correct source code..

tq

[Håkon Alseth]

Hi,

 

The pins P0.06 and P0.08 are still connected to an unpowered IC if you only power via the "nRF USB" connector, which would sink current through the unpowered IC.

Here's a modified DTM (from SDK 15.2) with P0.20 and P0.21 used: nrf52840_xxaa_dtm_p020_p021.hex

Could you try these pins and see if that works better?

Kind regards,

Håkon

[New Guy]

Hi,

Thank you for the .hex file, the P0.20 is Tx ? P0.21 is Rx ?

There is an error during flashing the hex file into my nRF52840 development kit. Below is the error pop out when I tried to flash my board using nRFgo Studio.

Then i used J-Flash Lite v6.40 to do flashing, and the program shows me the flashing is completed. However, I still failed to get the address on MT8852B. 

Here are some questions from me:

1. i need to flash softdevice first then only can flash the application software?

2. why i the flashing result is "completed" when using J-Flash Lite? and, it is really flashed?

3. on the Anritsu MT8852B, i tried both BLE2WIRE & RS232 to get the address but none on them working. I assumed there is no UART communication between Anritsu and DUT.

4. i noticed there are few supply port on the nRF52840 DK board. what is your configuration about that to make it works ?  

TQ, looking for your advice.. 

[Håkon Alseth]

Hi,

 

1 and 2.) No need to program the softdevice. Use nrfjprog from the command line:

nrfjprog -e && nrfjprog --program path\to\dtm.hex --reset

3.) You shall use BLE2WIRE and connect the RXD/TXD to pins P0.20 and P0.21. "RS232" is for classic BR/EDR bluetooth testing.

4.) As long as the nRF is powered up and the debugger is connected, it should be fine. Please see the nRF52840 user guide for more details on what the different switches do.

Kind regards,

Håkon

[New Guy]

Hi,

I tried again using nrfjprog command tool and segger embedded studio to do programming. The LED on the board is able to blink when i flashed with the example code for led blinking; but it still not able to communicate with anritsu tester after i flashed it with the dtm (examples file) and also your file is not working.

I noticed above statement from the user guide. It said about U5 & U6 break the connection of the UART, is this a reason why there is no return from the board??

best regards,

[Håkon Alseth]

Hi,

 

Did you connect the GPIOs P0.20 (RXD) and P0.21 (TXD) to your bluetooth tester? Could you post a photo of your setup?

If you want to use other GPIOs, you can modify the example as I posted in my initial reply.

New Guy said:

is this a reason why there is no return from the board??

If you have cut the solder bridges, and you're using the default GPIOs, then they will be cut.

By switching the GPIOs to any other free GPIO, you need to manually connect these to your UART adapter.

Kind regards,

Håkon