Protocol Definition between Ground Stations and Command RX
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Introduction
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- using DTMF on FM
- receiver should be activated for min. 200ms every 5s to listen for new commands
- signs get scrambled using a secret Code Table
- every command must be aknowledged by a beacon with the unscrambled code

Frame
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#42<code><cs>

Checksum:
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XOR over Signs intrepreted as HEX (0-9A-D#*) -> (0-9A-F)

Codes:
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0    ..    shut up (rfkill)
1    ..    unshut up (no rfkill)

8    ..    activate payload receiver

C    ..    cancel all commands
#    ..    reset
*    ..    safe mode (stop all activties and harvest energy)