Example code for fixed frequency for CE certification

[Mr Sunshine]

Hello,

For CE certification and to use BLE I require to set my custom board that uses a nrf52832 chip with onboard antenna to one or multiple Frequencies. From other posts I read that I should use the radio_test example or the direct_test_mode code in combination with the nRF connect for desktop program. My issue is that these examples use UART and when I flash this code on my custom board through my J-link I get stuck on the line NRF_BREAKPOINT_COND.

I am looking for an example that automatically transmits the set frequency after flashing without the need for UART. Is there such example?

Kind regards,

[Kenneth]

Hello,

I assume if you add a pull-up on the RXD pin you avoid the assert, but to answer your question about avoiding to use UART the answer will depend a bit on whether you have used nRF5 SDK or nRF Connect SDK during development. Can you specify?

Kenneth

[Mr Sunshine]

I am not familiar with the terms nRF5 SDK and nRF Connect SDK. I use the codes in the example file of SDK 15.0.0. version (which uses the s132_nrf52_6.0.0_softdevice), this is the version used for the current code for the complete product. Does this help?

Kenneth said:

I assume if you add a pull-up on the RXD pin you avoid the assert

I can try this out.

[Kenneth]

Hi again,

You are using the nRF5 SDK then, for future development we recommend the nRF Connect SDK:
Why? https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/nrf-connect-sdk-and-nrf5-sdk-statement 
Getting started? https://academy.nordicsemi.com/ 

But to answer your question for the nRF5 SDK and radio regulatory testing:

You can use the radio test example as a starting point:
https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/nrf_radio_test_example.html 

For instance to perform the ETSI tests you need to configure the radio in 2 modes (modulated tx and rx) and it needs to be performed on 3 channels (2, 40 and 80 (low, middle, and upper)). So in total 6 configurations are needed (I believe this is same for FCC and others).

Alternatively, instead of having the operator to write these commands manually for each configuration, it is also possible to make 6 hex files that setup the required tests (then you only need to program a new hex file for each test). You can use the main.c in the below linked devzone case as an example on how to setup fixed radio tests:
https://devzone.nordicsemi.com/f/nordic-q-a/82474/case-about-dtm-and-rf-channel/342390 

During ETSI test there is also a receiver blocking test (you can't use the radio test example on this one), instead you need to use the final application to test functionally that the product can operate with high out of band interference. For instance you can use some kind of blinky that indicate that the link is running and that pressing a button is received on the peer during this test.

For anyone that may find this thread in the future and is working on the nRF Connect SDK you may find this useful:

https://devzone.nordicsemi.com/support-private/support/289537#permalink=760591 
(update: https://devzone.nordicsemi.com/f/nordic-q-a/88247/is-it-possible-to-make-the-nrf5340-ic-transmit-a-cw/369586 )

You should be able to modify the cmd_tx_modulated_carrier_start() in main.c in the linked example to setup the channels you want to test.

Let me also add the following, since it can be useful later:

For the BT listing:

Here we have done pretty much all the job for you, you only need to list your product using one of the QDID that we list in this link (the QDID to use depends on which development platform and version you used when developing the product):
https://infocenter.nordicsemi.com/topic/comp_matrix_nrf52832/COMP/nrf52832/ble_qdid_qual_matrix.html (update: https://docs.nordicsemi.com/bundle/comp_matrix_nrf52832/page/COMP/nrf52832/ble_qdid_qual_matrix.html)

For more information also see:
General: https://www.bluetooth.com/develop-with-bluetooth/qualification-listing/ 
When using QDID: https://www.bluetooth.com/develop-with-bluetooth/qualification-listing/qualification-process-with-no-required-testing/ (update: https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/protocols/bt/bt_qualification/index.html)

Even though no specific testing is required when using a QDID, we do recommend that you perform DTM tests on a prototype to verify that your RF phy is good:
nRF5 SDK: https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/ble_sdk_app_dtm_serial.html 
nRF Connect SDK: https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/samples/bluetooth/direct_test_mode/README.html 

The DTM is also something you can do as part of your production test:
https://infocenter.nordicsemi.com/topic/struct_appnotes/struct/appnotes_nan34.html (update: https://docs.nordicsemi.com/bundle/nan_34/resource/nan_34.pdf)

Best regards,
Kenneth

[Mr Sunshine]

Hello Kenneth,

Thank you for the response, it helps a lot. The solutions you gave seem to help and I currently don't get stuck on the NRF_BREAKPOINT_COND line. I still have to test if my custom board is actually transmitting the set frequencies. 

Kenneth said:

For instance to perform the ETSI tests you need to configure the radio in 2 modes (modulated tx and rx) and it needs to be performed on 3 channels (2, 40 and 80 (low, middle, and upper)). So in total 6 configurations are needed (I believe this is same for FCC and others).

With the examples given I am able to change the channel by editing the .channel_start value. But it is unclear to me how I can set the modulated TX and RX modes.

[Kenneth]

Mr Sunshine said:

With the examples given I am able to change the channel by editing the .channel_start value. But it is unclear to me how I can set the modulated TX and RX modes.

This is controlled by one of these (presuming you are looking at this example):

m_test_config.type = MODULATED_TX; // Modulated TX
m_test_config.type = RX; // RX (its always modulated)

Kenneth

[Mr Sunshine]

I uploaded the hex files here for other people who have a similar issue. Here are 6 files for channels 2, 40 and 80 with modulated TX and RX mode. These files are made for the nrf52832 and can be written on them with use of the 'nrfConnect for Desktop' and 'programmer' program

radio_test_pca_ch02_modTX.hex

radio_test_pca_ch02_RX.hex

radio_test_pca_ch40_modTX.hex

radio_test_pca_ch40_RX.hex

radio_test_pca_ch80_modTX.hex

radio_test_pca_ch80_RX.hex

[Kenneth]

Thanks for sharing!