custom nRF5340 board no bluetooth signal

[danny0007]

Hi Community,

I designed a similar board asThingy53, espacially the antenna parts are almost the same, except the RF switch, we replace it with another one (BGS12WN6E6327XTSA1), then we found there is some issue to make the switch work properly, so I just removed the RF switch and short the RF output to the short range antenna, which means, now only one anntenna is connected to the RF, even so, I cannot see any RF signal on the mobile phone. 

but the output from UART seems no problem:

*** Booting nRF Connect SDK v3.5.99-ncs1 ***
[00:00:00.303,100] <inf> Custom_board: Starting Custom_board...

[00:00:00.309,020] <inf> fs_nvs: 8 Sectors of 4096 bytes
[00:00:00.309,020] <inf> fs_nvs: alloc wra: 0, fd0
[00:00:00.309,051] <inf> fs_nvs: data wra: 0, 1c
[00:00:00.334,167] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
[00:00:00.334,197] <inf> bt_hci_core: HW Variant: nRF53x (0x0003)
[00:00:00.334,228] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 54.58864 Build 1214809870
[00:00:00.336,456] <inf> bt_hci_core: No ID address. App must call settings_load()
[00:00:00.338,897] <inf> bt_hci_core: Identity: E6:BD:87:6D:09:49 (random)
[00:00:00.338,928] <inf> bt_hci_core: HCI: version 5.4 (0x0d) revision 0x218f, manufacturer 0x0059
[00:00:00.338,928] <inf> bt_hci_core: LMP: version 5.4 (0x0d) subver 0x218f
[00:00:00.342,742] <inf> Custom_board: Bluetooth initialized

[00:00:00.348,327] <inf> Custom_board: Advertising successfully started

the same code, if I compiled it for the nRF5340DK, the bluetooth signal can be observed. 

So I just curious if I did something wrong in my board files or something else? 

I have been strugled in this issue for a long time, please help me with it, thanks a lot!

Best regards

Danny

[JONATHAN LL]

Have you hade the design fully reviewed by us? 


My guess is that there is an issue with the antenna or RF path in some way and that this impacts the range, so maybe you need to be very close, try a few centimeters. And only have the PCB, if there is any casing or other material in the way or enclosing the antenna\PCB this might be a reason to why the RF is bad. 


Alternatively it might be the the clock, the 32MHz might be off and that can contribute to the issue. Make sure it is loaded correctly. 

Regards,
Jonathan

[danny0007]

Hi  JONATHAN LL 

1. it's not reviewed by you. I just checked the Thingy53 PCB file, found the followed differences:

Thingy53 PCB:

trace width: 0.6mm

grounded vias around the clear area of antenna .

My PCB:

trace width: 0.18mm:

I used this calculation, therefore I used 0.18mm RF trace width, is there anything wrong?

forgot to put grounded vias around the clear area of antenna.

I even put the PCB very close to the mobile phone, still can not see any siganl from my PCB.

2. I think I checked the 32M Hz crystal before, it's running, and all the other peripherals are running correctly, I2C, SPI, PWM...


Best regards
Danny

[JONATHAN LL]

The dongle does not need a softdevice with this setup so this should not be needed. Are you using the rf_test_dongle_nrf52840_dongle.hex found it the dongle firmware folder? just drag it in to the programmer app. 


How does the prompt show up ? 

Regards,
Jonathan

[danny0007]

Sorry, I was using the hex\nrf52840.hex.

Ok, now the one you mentioned is flashed.

I can see the Nordic Semiconductor RF test and WinUSB is installed.

However I get the same error:

Regards
Danny

[JONATHAN LL]

danny0007 said:

Sorry, I was using the hex\nrf52840.hex.

Ok, now the one you mentioned is flashed.

This is good progress, we are getting somewhere.

The no backen available error i am not sure exactly what is caused by. But i suspect that it has something to do with the premissions or path available in the folder where the app runs.

I will check with the developer and see what voibe the root cause.

Regards,

Jonathan 

[Bendik Heiskel]

Hi Danny,

The "No backend available" error comes from a missing libusb-1.0.dll.

This should have been installed by the libusb-package in the requirements.txt file.

Do you have multiple python versions installed on this computer?

If so, did you run the pip install command using the same python version you are using for running the application?

 

It is possible to install this dll manually. It can be downloaded form the libusb github repository(in the .7z file):

https://github.com/libusb/libusb/releases

the libusb-1.0.dll file must be placed in C:\windows\system32

 

Best regards,

Bendik

[danny0007]

Hi Bendik Heiskel 

thanks a lot. it seems working.

I copied the libusb-1.0.28\MinGW64\dll\libusb-1.0.dll file in C:\windows\system32

I also flashed the empty_app_core.hex and nrf5349.hex on nRF5340DK board.

USB dongle and nRF5340Dk both are connected to the laptop, then start the GUI. it looks like this:

So what's the next steps, how to perform the RF test? 

Regards

Danny

[Bendik Heiskel]

Great to hear that it works, you're the first person to try this application other than me. I'll be updating the instructions based on the issues you experienced to make it easier in the future.

 

The test software can be used to set the radio in different modes. Unmodulated TX sets the radio to transmitt a carrier at a given frequency and output power. With a spectrum analyzer this can be used to verify the output power and frequency accuracy of the radio/32MHz crystal.

By default the settings are configured for a 0dBm carrier on 2440MHz. The firmware on the DUT will start the radio in RX mode waiting for a command from the application, pressing the start button will send the test configuration to the DUT, if this is successfull the start button will turn green. The DUT will automatically cange the radio to the configuration send from the application and start the radio. To use a different test configuration the DUT must be restarted, by either the reset button or by power cycling the board.

 

What exactly is it you are trying to test?