Lost plane and voltage alarm

Yes, my proto looks ugly. But it works!

Functions:

Voltage indicator: know your Lipo status by counting the number of LED bursts. Simple telemetry ;-)
1 LED flash = full battery / 4 LED flashes = almost empty
Low voltage alarm:if you hear the beeps it is time to land.
at take off, a 20 minute timer is started automatically (voltage drop). If your plane crashes, it will start beeping after that time, with increasing intensity
Componants cost about 10 euro:

1x Arduino Nano
2x beeper