groundstation-linux-arm64 — the long-running root supervisor. It owns the GX12 UART, logging, RC state, video lifecycle, and starts the display process.
groundstation-display-linux-arm64 — the unprivileged X11 kiosk renderer. It runs as orangepi on DISPLAY=:0; the supervisor owns it during normal use.

Current capabilities:

receives framed GX12 RC channel data at 115200 8N1;
validates protocol version, frame length and CRC-16;
logs channel changes instead of every frame;
starts/stops fpv-video from the configured CH6 power/lifecycle control;
starts an independent kiosk display before video, tolerates temporary X11 downtime without restarting the supervisor, and stops deterministically on shutdown;
keeps the fullscreen fallback/menu canvas below fpv-video, showing Brak połączenia WFB only while video is absent;
maps a transparent, input-transparent OSD overlay above fpv-video as the reserved flight OSD rendering surface: it never presents pixels over the video or intercepts its input.

Future MIPI/touch targets use their own templates rather than sharing one global layout. The flight OSD will render on the existing transparent layer above video, preserving the pilot stream's priority.

Installation on Orange Pi

Extract the artifact and install both files:

sudo install -m 0755 groundstation-linux-arm64 /usr/local/bin/groundstation
sudo install -m 0755 groundstation-display-linux-arm64 /usr/local/bin/groundstation-display
sudo systemctl restart groundstation

Check logs:

systemctl status groundstation --no-pager
journalctl -u groundstation -b --no-pager -n 80

Do not run groundstation-display by hand during normal operation. It needs the X11 user/session environment and is managed by the supervisor. For isolated renderer debugging it supports:

groundstation-display -target x11

Configuration

The service reads /etc/groundstation/config.yml. For the verified permanent GX12 connection, use:

serial:
  path: /dev/ttyS2

/dev/ttyS0 is the Orange Pi boot/debug UART and must not be used for the permanently connected GX12.

Runtime dependencies

X11 session on :0 owned by orangepi; the kiosk waits for X11 and reconnects after display-manager restarts;
wmctrl for the fullscreen/stacking kiosk window states; without it the kiosk windows map as normal windows and the condition is logged;
runuser from util-linux for the unprivileged kiosk launch.