Hello,
I’d like to switch my drone on and off using software. This means, that I have e.g. a python script or a C-program that sends a command to the switch, for example via Wifi or Bluetooth. So far, I haven’t found any ready made hardware. In fact, I haven’t even found suitable implementations with simple mechanical switches. Most people seem to be content with ripping huge power cables apart everytime they power off their drone 
I’m currently thinking about using a Wifi enabled microcontroller (e.g. an ESP8266) which operates a relay that sits between battery and drone. Once the relay cuts power, the switching electronics would be powerless too, so the power for relay and controller will come from electrical contacts on the landing platform once the drone is landed.
I’m not yet sure what relay I could use:
- It has to withstand a lot of current.
- I want the drone to switch off when the relay is powered and switch on when the relay has no power. Therefore it needs a contact that is closed when the relay has no power (Normally-Closed-Port, NC). Solid state relays don’t have this and are therefore out of the question.
Maybe I could use an automotive relay like this one?
Does anybody have any experience with that? Note that my question is not so much about software development but mainly about recommended hardware.
Thanks and best regards
Janis