Quick question on u.FL port on nrf52840

[kongstrupp]

Hello!

Quick question: When a device is connected to the u.FL port (actively transmitting things to the port) on the nrf52840 board, does board (in rx mode) only listen to that port or does it still capture communication on air? If not, is there an option to configure this?

Thanks!

[ketiljo]

The radio can either transmit _or_ receive. There's only one antenna pin so whatever it connected to this pin is where it will transmit or receive to.

[kongstrupp]

Okay, but if this port/connector is hooked up, is it still possible for the nrf board to still receive packets on air? Or can it ONLY recive/transmit packets that is going to whatever the u.FL port is hooked up to?

[ketiljo]

If you are using a development kit, the connector is not U.FL but SWF: https://infocenter.nordicsemi.com/topic/ug_nrf52840_dk/UG/dk/hw_rf_measure.html

The antenna is disconnected when a connector is inserted.

[kongstrupp]

Thanks for the clarification! Is there a way to verify that the connector is connected? and if the antenna is disconnected? So you could know for 100% that everything being received to the board is from the SWF connector? 

[ketiljo]

If the signal is strong enough, it might leak into the circuit between the connector and the ANT pin. So you can't be 100% sure.