Stabilize voltage input for Arduino nano on a drone
I would not use this arrangement, except in some rare scenarios.

The lipo batteries are a very low impedance voltage source, so if you use good routing, and decoupling you shouldn't need any filter.


Route the power from as near the battery as possible. You don't want to share wires that are supplying current to the motors if possible.
Add a large electrolytic cap, 100-1000uF (depending on the size of the drone), right near the battery in the circuit. Almost all drone builders do this, and it seems to reduce overall system noise.
Add 1 or more 0.1uF decoupling caps near the arduino, and maybe an additional smaller electrolytic.
Make sure your voltage regulators have enough input voltage to keep working even when the battery is near dead and heavily loaded. The voltage may sag 15% or more under load, depending on the battery quality. If you're regulator is 5v and your battery is 2s, you're pretty much at the limit. Consider switching to a LDO regulator, or switching the system to 3.3v if this is the case.


LC filters are sometimes used on sensitive electronics in drones, but I can say from first had experience that they can easily make things worse instead of better. Explore those as a last resort, after you've tried all this.