Logitech C270 Webcam in Mainsail
Crowsnest via KIAUH

Crowsnest is the Mainsail-crew webcam service (it replaces the old webcamd / mjpg-streamer). It streams with ustreamer, and Mainsail reads it at /webcam/.

1. Install Crowsnest with KIAUH

cd ~ && git clone https://github.com/dw-0/kiauh.git   # skip if you already have it
./kiauh/kiauh.sh

Choose Install → Crowsnest. In newer KIAUH versions it may be listed under Extensions.
Accept the defaults. When it asks to add the Moonraker update manager entry, say yes.
Reboot if the installer asks you to.

MainsailOS already ships with Crowsnest. Check with ls ~/crowsnest before installing it again.

2. Find the camera device

sudo apt install v4l-utils   # if v4l2-ctl is missing
v4l2-ctl --list-devices
ls -l /dev/v4l/by-id/

The C270 shows up as something like usb-046d_0825_XXXXXXXX-video-index0. Use the by-id path ending in -video-index0, because /dev/video0 can change between reboots. You can also check what the camera supports with v4l2-ctl -d /dev/video0 --list-formats-ext.

3. Configure crowsnest.conf

In Mainsail open Machine → crowsnest.conf, or run nano ~/printer_data/config/crowsnest.conf:

[cam 1]
mode: ustreamer
enable_rtsp: false
rtsp_port: 8554
port: 8080
device: /dev/v4l/by-id/usb-046d_0825_XXXXXXXX-video-index0   # your real path
resolution: 1280x720      # or 640x480 for smoother, lighter streaming
max_fps: 15               # the C270 does ~30 fps at 640x480, less at 720p
# custom_flags: --allow-broken-frames
# v4l2ctl: power_line_frequency=2   # 2 = 60 Hz (US); stops flicker

4. Restart Crowsnest

sudo systemctl restart crowsnest
systemctl status crowsnest
cat ~/printer_data/logs/crowsnest.log

Or restart it in Mainsail from the power/services menu: crowsnest → Restart.

5. Add the webcam in Mainsail

Open the gear icon → Webcams → Add Webcam
Name: C270
URL Stream: /webcam/?action=stream
URL Snapshot: /webcam/?action=snapshot
Service: MJPEG-Streamer, or Adaptive MJPEG-Streamer if your network is slow
Save. The feed appears on the dashboard.

To test it directly, open http://<printer-ip>/webcam/?action=stream in a browser.

6. Common fixes

Problem	Fix
Camera not detected / drops out	Use a different USB port (preferably directly on the Pi/CB1, not a hub), try a shorter cable, and check `dmesg \| tail` for under-voltage or USB resets. Weak power supplies often cause this.
Low FPS / laggy	Lower to `640x480` and/or `max_fps: 15`. The C270 is USB 2.0 and slows down in low light, so add more light. Use the Adaptive MJPEG service in Mainsail.
Black or no stream	Check the `device:` path, then check `crowsnest.log`. Make sure no other webcam service (webcamd/mjpg-streamer) is using port 8080.
Flicker / banding	`v4l2ctl: power_line_frequency=2` (60 Hz)
Crowsnest missing from Update Manager	Add the entry below to `moonraker.conf`, then restart Moonraker.

[update_manager crowsnest]
type: git_repo
path: ~/crowsnest
origin: https://github.com/mainsail-crew/crowsnest.git
managed_services: crowsnest
install_script: tools/pkglist.sh

Also make sure ~/printer_data/moonraker.asvc contains a crowsnest line so Moonraker can restart the service.