Synchronize RF switch to BLE activity

[maximevince]

Hi Nordic,

We have a design where we'd like to share the 2.4 GHz antenna between WiFi and BLE.

Therefore, we need to power and configure the RF switch accordingly, before every RF activity (RX and TX).

We're using an nrf52833 and the Zephyr RTOS. Is there a way to configure the MCU so it wakes slightly before any RF slot, so that the firmware gets a possibility to configure the RF switch in time?

Even better would be to use GPIOTE or similar to do this automatically, instead of having to wake the MCU for this and execute the switch in software.

Thanks,

Maxime

[JONATHAN LL]

Hi,

We have a design where we'd like to share the 2.4 GHz antenna between WiFi and BLE.

This can be done.

Is there a way to configure the MCU so it wakes slightly before any RF slot, so that the firmware gets a possibility to configure the RF switch in time?

There are some coexistence options:

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrfxlib/mpsl/doc/bluetooth_coex.html#bluetooth-coex 

Bluetooth: External radio coexistence using 1-wire interface — nRF Connect SDK 1.9.99 documentation (nordicsemi.com) 

This is most likely the one you want to look at: IEEE 802.15.4 External Radio Coexistence — nrfxlib 1.9.99 documentation (nordicsemi.com) 


Regards,
Jonathan

[maximevince]

Thanks for your reply. None of the existing 3-wire or 1-wire interfaces exactly fit our use-case, but as stated in the  IEEE 802.15.4 External Radio Coexistence — nrfxlib 1.9.99 documentation (nordicsemi.com) page:

If the radio coexistence implementation provided in nRF Connect SDK is not compatible with the PTA used in your system, you can implement a software module compatible with your PTA that exposes the radio coexistence API, using the nrf/subsys/mpsl/cx/thread/mpsl_cx_thread.c file as an example.

Which is what we'll do. Thanks!