Is there a good example for using direct test mode, with an nrf53 and using an external xtal?
What application mcu code to use? And does it enable the LF xtal pins?
Is there a good example for using direct test mode, with an nrf53 and using an external xtal?
What application mcu code to use? And does it enable the LF xtal pins?
And to amend this. Should the uart interface for direct test be on the network or application cpu?
Hello,
We include a dedicated Direct test mode sample application in the SDK you can use. The documentation for it can be found here: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/bluetooth/direct_test_mode/README.html . This application is only meant to be run on the net core. So the UART interface will be on the network core as well.
The program will always start the HFXO crystal oscillator before the RADIO is used, but for the LF xtal pins it will depend on the board configuration. The Nordic DKs select the crystal by default, but you can override this by adding CONFIG_CLOCK_CONTROL_NRF_K32SRC_RC=y to the prj.conf file inside the project folder.
Best regards,
Vidar
That didn't cover the question of what application core code base to use.
Since the application core, starts the netcore and sets the pin usage, this requires a application core code.
Is there an example I can follow?
Sorry, I missed that part of your question. For the app core you can use "empty app core" sample in \nrf\samples\nrf5340\empty_app_core.
"On the nRF5340 development kit, the Direct Test Mode sample is a standalone network sample. It does not require any counterpart application sample. However, you must still program the application core to boot up the network core. You can use any sample for this, for example, the nRF5340: Empty firmware for application core."