Add electronic signalling based on the sending of “beacon” frames over Wifi

[ZinhoRacing]

French law will soon (July 2020) request that all UAVs weighing 800 grams or more at takeoff must be equipped with a device that allows to electronically signal its presence.

This electronic signalling is based on the sending of “beacon” frames with Wifi equipment using a structure and protocol defined in the text of the law.

I just found an issue on Inav git on that subject (iNavFlight/inav#5799 (comment)) with a link to a nice solution made by @khancyr https://github.com/khancyr/TTGO_T_BEAM.

I think inav radar could also do the job with small modifications.
I already fly a plane with inavradar module.

I'll try to start to add it.

If some one intrested I'll be please to have some help.

[KingKone]

Nice! Sounds interesting, at the moment I have no setup with inavradar, but i will help making a release out of it.

Also, i remember, we had brownout problems when using WIFI AP on the modules. Needs more stable power, maybe a cap could solve that problem.