FarmBotOS is the C and Elixir/Erlang-based code and the OTP Erlang runtime.
This runs as a handful of Linux processes on a Buildroot-based Linux OS which not really a “distro” as such but is a hand-crafted Linux build tailored for and cross-compiled for the target platform : Raspberry Pi.
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@SimonB Did you search this forum ? I found this post which still seems relevant 
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@SimonB at least your post is in the most promising category
This feature should be readily accomplished with a tweaked version of farmbot_system_rpi3 Elixir/Nerves package.