PA/LNA for mesh stack but not softdevice

[ftjandra]

A continuation from here: https://devzone.nordicsemi.com/f/nordic-q-a/64842/mesh-pa-lna-problems

If I want to only enable the PA/LNA chip for the mesh stack, but not for the softdevice I need it to toggle the 'bypass' pin on the PA/LNA chip. I.e. set a gpio low during mesh communications and high during regular BLE communication? How would I do this?

Also, can I do the sd_ble_gap_tx_power_set(BLE_GAP_TX_POWER_ROLE_ADV, m_adv_handle, ...) at the end of the mesh_adv_data_set() function in mesh_adv.c since that is where the handle is set?

Thanks.

[Hung Bui]

Hi Ferdi, 

I'm sorry that I didn't response to the previous case. The case was marked with accepted answer and I didn't get the notification when you added a comment. 

Regarding this question, we recently got a very similar question on devzone here: https://devzone.nordicsemi.com/f/nordic-q-a/66292/nrf52832-and-sky66112-11-pa-lna-usage-in-gatt-and-mesh

We are checking with our Mesh team to provide a solution. 

But basically what you are asking for is in addition to not triggering the PA/LNA pins when the radio is active, you also need the bypass signal to be triggered when the softdevice is operating.

I think this could be done the same way as how we configure the PA/LNA pins, just the opposite. If you have a look inside mesh_pa_lna.c file you can find that we connect the GPIO task to toggle the pins to the EVENT_COMPARE event from the timer. So the timer event will trigger the GPIO pins to flip. You can use an extra PPI channel to do the same thing for your bypass pin. So when the timeslot in mesh is active bypass is inactive and when timeslot (bearer active) is inavite you turn the bypass on for the softdevice to operate. 

I will let you know when we have an update from the mesh team of what exactly need to be done. But you can try to do what I suggested.