BTFL 3.4.0 Upgrade

Managed to upgrade several older quads with BTFL 3.2.2 on Betaflight F3 flight controller to BTFL 3.4.0/3.4.1 today:

Genius1 BTFL 3.4.0
Genius2 BTFL 3.4.0
Iflight7 BTFL 3.4.0
Dragon220 BTFL 3.4.1
GEPRCONE BTFL 3.4.1
PUDA240 BTFL 3.4.1
REAL250 BTFL 3.4.1
GTR7-300 BTFL 3.4.1
GTM7-300 BTFL 3.4.1


These quads were all on Betaflight F3 flight controller and were easily flashed using the ImmersionRC driver fixer in DFU mode.

Also tried upgrading EX220-2 which was on Betaflight F4 flight controller however that didnt go very well with the ImmersionRC (failed, more than one device detected). Unable to sort it out using Zadig either. I cant remember how the F4 flight controllers were flashed the first time ... a boot pin maybe.

For now the first task is to upgrade all F3 flight controller quads to BTFL 3.4.1, second task is to put these through test flights and the third task is to upgrade those quads on F4 flight controllers.

Now where is that boot pin ...