Architecture Overview

Novabot Cloud Unreliable

The Novabot cloud (app.lfibot.com / mqtt.lfibot.com) has been experiencing frequent outages since March 2026. OpenNova keeps your mower operational regardless of cloud status.

System Diagram

graph TB
    subgraph Internet
        Cloud[app.lfibot.com<br/>Cloud API Server<br/>Unreliable since March 2026]
        MQTT_Cloud[mqtt.lfibot.com<br/>Cloud MQTT Broker<br/>Unreliable since March 2026]
    end

    subgraph "Docker Container (Mac/NAS/RPi)"
        DNS[dnsmasq<br/>DNS rewrite *.lfibot.com]
        Server[server<br/>Express + Aedes MQTT]
    end

    subgraph "Host Machine (native)"
        Bootstrap[Bootstrap Wizard<br/>BLE provisioning + mDNS]
    end

    subgraph Devices
        Charger[Charging Station<br/>ESP32-S3 / LFIC1230700XXX]
        Mower[Robot Mower<br/>Horizon X3 / LFIN2230700XXX]
    end

    App[OpenNova App<br/>React Native]
    HA[Home Assistant<br/>MQTT Bridge]

    DNS -->|Redirects *.lfibot.com| Server
    App -->|HTTP REST + Socket.io| Server
    App <-->|BLE GATT| Charger
    App <-->|BLE GATT| Mower
    Bootstrap <-->|BLE provisioning| Charger
    Bootstrap <-->|BLE provisioning| Mower
    Charger -->|MQTT plain JSON| Server
    Mower -->|MQTT AES-128-CBC| Server
    Charger <-->|LoRa 433MHz| Mower
    Server -->|MQTT auto-discovery| HA

    Cloud -.->|Replaced by local server| Server
    MQTT_Cloud -.->|Replaced by local broker| Server

Communication Layers

graph LR
    subgraph "App <-> Server"
        A1[HTTP REST<br/>Port 3000]
        A2[MQTT<br/>Port 1883]
    end

    subgraph "App <-> Server"
        B1[HTTP REST<br/>Port 3000]
        B2[Socket.io<br/>WebSocket]
    end

    subgraph "Charger <-> Server"
        C1[MQTT Plain JSON<br/>Port 1883]
    end

    subgraph "Mower <-> Server"
        D1[MQTT AES-128-CBC<br/>Port 1883]
        D2[HTTP Uploads<br/>Port 3000]
    end

    subgraph "Charger <-> Mower"
        E1[LoRa 433MHz<br/>Binary packets]
        E2[RTK GPS Relay<br/>NMEA via LoRa]
    end

Technology Stack

Server (server/)

Layer	Technology
Runtime	Node.js + TypeScript (ESM modules)
HTTP	Express.js
MQTT Broker	Aedes (port 1883)
WebSocket	Socket.io
Database	better-sqlite3 (WAL mode)
Auth	JWT (jsonwebtoken + bcrypt)

OpenNova App (app/)

Layer	Technology
Framework	React Native + Expo
Platforms	iOS + Android
BLE	NimBLE (provisioning)
Maps	SVG-based with GPS conversion
Real-time	Socket.io client

Bootstrap Wizard (bootstrap/)

Layer	Technology
Runtime	Node.js + TypeScript
BLE	@stoprocent/noble (native) + Web BLE (browser fallback)
mDNS	Bonjour/Avahi advertisement
Purpose	First-time firmware patching, BLE provisioning, mDNS opennovabot.local

DNS (inside Docker container)

Layer	Technology
Container	Alpine Linux (~8MB image)
DNS	dnsmasq
Purpose	Redirect *.lfibot.com to local server IP

Distribution Model

The project uses a Docker-based distribution where the server runs on the user's local network (Mac/NAS/Raspberry Pi), NOT on the mower itself.

Why Not On The Mower?

• CPU load impacts mowing performance
• Battery drain from running Node.js server
• Heat buildup from continuous server operation
• Brick risk if server crashes
• No app access when mower is offline/sleeping

Components

Component	Runs On	Purpose
Docker container	Mac/NAS/RPi	server + dnsmasq
Bootstrap wizard	Host machine (native)	Initial setup, firmware patching, mDNS advertising
Custom mower firmware	Mower	SSH, URL patches, camera, mDNS discovery

Server Discovery

The mower finds the local server via a fallback cascade (custom firmware v6.0.2-custom-16+):

1. mDNS query for opennovabot.local (8 second timeout)
2. Last-known IP from previous successful connection
3. Fallback host (hardcoded during firmware build)
4. Skip -- mower continues without server connection

mDNS runs on the host, not in Docker

The bootstrap wizard advertises opennovabot.local via mDNS on the host machine. Docker bridge networking blocks multicast on macOS, so mDNS runs natively in the bootstrap tool, not inside Docker.

Database Schema

Table	Purpose
users	User accounts (email, bcrypt password, machine_token)
email_codes	Temporary verification codes
equipment	Bound devices (mower_sn PK, charger_sn, mac_address)
device_registry	Auto-learned via MQTT CONNECT (sn, mac, last_seen)
maps	Map metadata (polygons stored as JSON)
map_uploads	Fragmented map upload tracking
cut_grass_plans	Mowing schedules per device
robot_messages	Device to user messages
work_records	Mowing session history
equipment_lora_cache	Cached LoRa parameters (survives unbind)
ota_versions	OTA firmware versions
map_calibration	Manual map offset/rotation/scale per mower
dashboard_schedules	Dashboard mowing schedules (CRUD + MQTT push)
virtual_walls	No-go zones / virtual boundaries per mower