Application of FEM chip in ESB

[mingjkl]

My project uses ESB for communication. In our hardware design, nrf5340 + FEM is used. Nrf5340 uses two GPIO link FEM chips to switch between PA mode and LNA mode. May I ask where the switching signals of the two gpios should be added to the ESB driver?

[ovrebekk]

Hi

In the ideal world you could just connect the TXREADY and RXREADY events of the radio to GPIO's using the DPPI and GPIOTE peripherals, but the problem then is that the pins would only be set very shortly before the packets are sent or received. 

I assume the FEM chip requires this pins to be set a bit before the communication takes place, and possibly they should also be cleared a bit after?

Best regards
Torbjørn

[mingjkl]

Thank you very much for your professional advice.

[ovrebekk]

Hi 

You welcome

In the end ESB doesn't properly support FEM devices out of the box, and you would need to do some modifications to the ESB implementation itself to support this. 

Best regards
Torbjørn