Everything N1MM Rotor Server can do

Up to 16 Rotors

Each rotor runs on its own USB serial port. All rotors operate independently with individual poll rates, offsets, and storm settings.

Adaptive Poll Rates

Idle rotors are polled at 1000 ms (configurable). When moving, the rate drops to 200 ms for smooth, responsive position tracking.

USB Auto-Reconnect

Detects serial port disconnection after 3 consecutive errors and retries every 5 seconds — no manual intervention required.

Heading Offset

Per-rotor offset from −180° to +180° compensates for mechanical misalignment. Applied transparently to all queries and broadcasts.

Stall Detection

If a moving rotor fails to change heading by at least 5° within 5 seconds, the server automatically declares a stall and returns to idle polling.

Simulate Mode

Each rotor can run in simulate mode — no serial port needed. Movement is modelled with a trapezoidal velocity profile (1.5–20°/s) for testing.

Incoming Commands (port 12040)

N1MM Logger sends XML packets to the server:

<N1MMRotor>
  <rotor>2m yagi</rotor>
  <goazi>180</goazi>
  <offset>0</offset>
</N1MMRotor>

<N1MMRotor>
  <rotor>2m yagi</rotor>
  <stop>1</stop>
</N1MMRotor>

Position Broadcast (port 13010)

The server broadcasts position to N1MM Logger:

2m yagi @ 1800 / 2250

Values are heading × 10 (tenths of degrees). The example above means current 180.0° / target 225.0°.

Wind-Aware Parking

Rotors are parked relative to the wind direction, not a fixed angle. A per-rotor storm offset lets you aim into the wind, away from it, or any other bearing.

Circular Direction Smoothing

Wind direction is smoothed using a circular mean of the last 10 readings, filtering out momentary spikes before applying storm correction.

Auto Return Timer

When always_controllable is enabled, a per-rotor timer automatically returns the antenna to the storm-safe position after a manual GOTO.

Ecowitt Weather Station

Receives live HTTP POST data from Ecowitt-compatible stations. Optional PASSKEY validation. Configurable fallback to an internet source when no push is received for N minutes. Data can also be forwarded to a second server.

Serial Wind Sensor

Connects to a serial wind anemometer on any configurable /dev/serial/by-path/ port at a configurable baud rate. Full extended meteo data when available from the sensor.

UDP Wind Data

Listens on a configurable UDP port for raw wind data packets. Useful when another system on the network is already receiving or computing wind information.

Public Backend (default)

Out of the box the maps come from the free, donation-run Open HamClock Backend (ohb.hamclock.app). The server prefetches politely in the background — one map per band per hour — so page loads never hit the backend.

Fully Self-Hosted (optional)

Want to be independent of any external service? setup_prop.sh builds a complete local VOACAP server (voacapl + voacap-service) on the same machine — free and open source, no subscriptions, no internet needed after setup. The installer offers it as an optional extra.

Server-Sent Events (SSE)

All live data (rotor positions, wind, log lines) is pushed to the browser via SSE — no polling, no WebSockets. Each client gets its own stream on /api/events.

User Accounts & Roles

Up to 8 accounts with three roles — User (rotor control), Manager (storm & day-to-day settings), Admin (everything) — with per-role permission checkboxes. New accounts get a temporary password by e-mail; "Remember me" keeps a login valid for 30 days. No accounts configured = open access with a first-run setup wizard.

Dark / Light Theme

Toggle between dark and light mode with the sun/moon icon in the menu bar. Theme is persisted in the browser.

Responsive Layout + PWA

Works on desktop, tablet, and mobile. Compass cards resize to fit the viewport, every rotor has a fullscreen view, and the dashboard installs as an app (PWA) on your phone's home screen.

Optional HTTPS

One script (setup_ssl.sh) puts nginx in front with a free Let's Encrypt certificate and automatic renewal — for secure access from outside your LAN.

Your Card Order

Arrange the rotor cards in any order with up/down arrows in Settings → Rotors. Open dashboards re-order live — no reload needed.

48-Hour Meteo History

Wind and meteo data is stored in a persistent CSV file (/etc/n1mm_rotor_server/wind_hist.dat) with automatic compaction every hour. Served as JSON via /api/hist-meteo. The web UI renders it as interactive graphs with 7 zoom levels.

24-Hour Rolling Log

The server log (/var/log/n1mm_rotor_server.log) keeps 24 hours of entries with automatic rotation. High-frequency broadcast lines are excluded to avoid noise. Access via web UI or /api/log.

HTTP Push Receiver

Listens on a configurable TCP port (default 49199) for HTTP POST pushes from the station. Validates optional PASSKEY. Applies a configurable wind speed correction factor.

Automatic Fallback

If no push is received for N minutes (configurable), the server automatically falls back to an internet weather source. Resumes local station data when pushes resume.

Data Forwarding

Optionally forward every received Ecowitt POST to a second host/port/path. Useful for redundancy or sharing data with other software. PASSKEY can be overridden in the forwarded body.

Three Roles

User — rotor control while no storm correction is active. Manager — storm control and day-to-day settings. Admin — everything, including accounts, server settings and power control. Per-role permission checkboxes fine-tune what each role may do.

Mailed Temporary Passwords

Creating or resetting an account mails a temporary password automatically; the user must change it at first login. A public "Forgot password" flow mails a new one — no SSH needed to recover an account.

Event Notifications

Branded HTML mails (with a one-click dashboard link) on storm-correction start/stop, wind-source failover, rotor connection lost/restored, and server start. Any SMTP provider — SSL, STARTTLS or plain — with a built-in test button.

Lightweight & Efficient

Written in C99 with POSIX threads. Minimal memory footprint — runs comfortably on a Raspberry Pi or any other Debian-based Linux system. Compiled with -O2. Two binaries: n1mm_rotor_server (rotor control) and n1mm_rotor_web (HTTP API).

Systemd Services

Both binaries run as systemd services with automatic restart. The web UI can trigger restarts, reboots, and shutdowns without root privileges via sudoers rules.

Interactive Setup Wizard

First-time setup via --setup wizard. Add rotors with --add, edit with --change, list with --list, delete with --delete — all from the command line.

Easy Updates

Included update.sh rebuilds and reinstalls binaries and web files, then restarts both services. A separate webupdate.sh updates only the web UI without recompiling.

Optional Extras

Two one-shot scripts extend the install when you want them: setup_prop.sh builds a fully local VOACAP propagation server, and setup_ssl.sh adds HTTPS with a free Let's Encrypt certificate (nginx reverse proxy, auto-renewal).