Bootloader + PA / LNA

[jumpingfool]

I am working on an application targeting the Fanstel BT840X, which combines nRF52840 and Skyworks SKY66112-11 PA / LNA on a single module.

I am using GPIOTE and PPI to drive the PA / LNA and all is working fine in the main application.

I then added PA / LNA support to the bootloader by following the advice in the thread at https://devzone.nordicsemi.com/f/nordic-q-a/28440/how-to-add-pa-lna-in-bootloader to initialise the PA / LNA inside ble_dfu_transport_init(). This does seem to have worked as signal strength from the bootloader has increased when it is advertising.

However, when attempting to establish a connection to the bootloader something is not right. The connection will only establish if the central (e.g. iPhone with the nRFConnect app) is in very close proximity to the module - a few feet at most.

I have no idea where to start on debugging this behaviour so any advice on what the issue might be would be very much appreciated!

[jumpingfool]

I found the issue, the problem was I was configuring the PA in the wrong place inside ble_dfu_transport_init - it needs to be after ble_dfu_init (I had it after ble_stack_init).

I'm not sure how this caused the symptoms I was seeing but moving it has resolved the problem!