Pi Deployment Guide

Tooling

Fedora 43:

sudo dnf install golang libgpiod

Cross-compiling roverd for Pi Zero 2 W (ARMv7):

cd pi/roverd
mkdir -p ../../dist
make pi-build

The binary is placed in dist/roverd (relative to the repo root).

Dummy rover build (for local testing)

If you need extra “virtual” rovers on your laptop/CI box, build the dummy binary:

cd pi/roverd
mkdir -p ../../dist
make dummy

Run the resulting dist/roverd-dummy on any machine; it will connect to the server, stream fake Group 100 sensor data, and log drive commands so you can test multi-rover features without additional hardware.

Automated installation (recommended)

Install the Raspberry Pi camera helpers (Bookworm ships them):

sudo apt update
sudo apt install libcamera-apps

Once the binary (and repo) are on the Pi, run the helper script from the repo root:

cd ~/MultiRoombaRover
sudo ./pi/install_roverd.sh

What the script does:

creates the roverd service account (dialout/gpio/video groups) if missing and installs /usr/local/bin/roverd
copies pi/roverd/roverd.sample.yaml to /etc/roverd.yaml if the file is absent (existing configs are left untouched)
installs/enables the roverd.service systemd unit, restarting it automatically when a config already exists
installs /usr/local/bin/video-publisher, drops video-publisher.service, and enables it so video is published automatically on boot

Flags:

Flag	Purpose
`-b PATH`	use a different roverd binary (defaults to `dist/roverd`)
`-c PATH`	seed `/etc/roverd.yaml` from another template

If the script installs the sample config, it will remind you to edit /etc/roverd.yaml before manually restarting the service: set name, serverUrl, serial device, BRC pin, battery thresholds, and optionally override media.publishUrl. When left blank, roverd automatically publishes to srt://<server-host>:9000?streamid=#!::r=<name>,m=publish… (the host comes from serverUrl).

Manual installation

Copy the binary and config:
```
sudo useradd -r -s /usr/sbin/nologin roverd || true
sudo install -o roverd -g roverd -m 0755 dist/roverd /usr/local/bin/roverd
sudo install -o roverd -g roverd -m 0640 pi/roverd/roverd.sample.yaml /etc/roverd.yaml
```
Adjust /etc/roverd.yaml for each rover: name, serverUrl (e.g. ws://control-server:8080/rover), serial port path, battery thresholds, GPIO pin for BRC, and (if needed) the media whepUrl override. Otherwise, roverd fills in http://<pi-ip>:8889/rovercam/whep based on the DHCP-assigned address.

Install the systemd unit:

sudo install -m 0644 pi/systemd/roverd.service /etc/systemd/system/roverd.service
sudo systemctl daemon-reload
sudo systemctl enable --now roverd.service

roverd requires access to /dev/ttyAMA0 and /dev/gpiochip*; keeping it under its own user ensures the rest of the system stays isolated—just make sure the account belongs to the dialout and gpio groups so it can reach the UART and libgpiod.
The WHIP publisher needs read access to the camera devices (/dev/media*, /dev/video*), so the install script adds the roverd service account to the video group; if you created the user manually, make sure it belongs to video.
BRC note: configure brc.gpioPin (and brc.gpioChip if you’re not using gpiochip0) and ensure the roverd user has permission to toggle that line—no root privileges are required anymore.
If you set media.manage: true in /etc/roverd.yaml, make sure the roverd service account can invoke systemctl <action> <media.service> (the installer wires video-publisher.service to run as roverd, so no sudo tweaks are required unless you rename it).

Video publisher details

The video-publisher.service unit runs /usr/local/bin/video-publisher, piping rpicam-vid/libcamera-vid straight into the stock FFmpeg package:

rpicam-vid (or libcamera-vid) --inline --timeout 0 --width=WIDTH --height=HEIGHT \
  --framerate=FPS --bitrate=BITRATE --codec h264 --profile baseline --output - \
  | ffmpeg -hide_banner -loglevel warning -fflags nobuffer \
      -f h264 -i pipe:0 -c:v copy -an -flush_packets 1 -f mpegts $PUBLISH_URL

/var/lib/roverd/video.env carries all tunables (PUBLISH_URL, resolution, FPS, bitrate). roverd rewrites the file whenever you restart it or hit the “Restart Camera” button so the publisher always inherits the correct rover ID + bitrate knobs. Because we now use the distro FFmpeg build with SRT enabled, the installer is much faster—no custom compile steps.
Use sudo systemctl status video-publisher to watch logs; the unit auto-restarts whenever the connection drops or FFmpeg exits with an error.

Server + UI

From the repo root:

cd server
npm install
npm run start

This launches the HTTP server (serving the barebones UI) and the rover WebSocket endpoint at ws://<server>:8080/rover. The UI expects roverd instances to send hello frames so it can populate the rover list. Use the mode buttons to emit Start/Safe/Full/Passive/Dock commands (they send the raw OI opcode bytes), tap the sensor toggle to request Group 100 streaming, and use WASD for drive testing; the UI emits Drive Direct commands ~8 times per second, so the rover sees them immediately.

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