nokkonen

A self-hosted home telemetry and device-management platform, primarily for conveniently ingesting data into Home Assistant, configuring local automations, and reliably managing and updating devices in bulk even remotely. A central Go service ingests sensor data over MQTT, stores it in SQLite, exposes a web dashboard, and publishes Home Assistant MQTT discovery. Around it sit a handful of small ingest/agent services and some ESP32/nRF firmware.

Everything talks over a single Mosquitto broker using the nokkonen/ topic namespace. Devices are keyed by a 12-hex-char ID (^[0-9a-f]{12}$), derived from a MAC or assigned per service.

Layout

services/        Go services (each an independent module)
  state-machine    central hub: MQTT ingest, SQLite, web UI, HA discovery, OTA + control
  ble-ingest       BLE (BlueZ/D-Bus) -> MQTT temp/humidity sensors
  ld-2450-ingest   LD2450 presence radar (serial) -> MQTT
  bme-680-ingest   BME680 environmental sensor (I2C) -> MQTT env (temp/rh/pressure/gas)
  machine-monitor  per-Linux-host agent: thermals/fans/disk/load + reboot/shutdown control
  wol-helper       LAN helper: Wake-on-LAN magic packets + ICMP reachability probes
firmware/        ESP32 / nRF (WM1110) sensor firmware
  esp32c3-radio_env, esp32s3-radio_env, wm1110-temp_rh
infra/mosquitto/ broker config (nokkonen.conf) and ACLs (nokkonen.acl)

Each service is its own Go module under the github.com/0mlml/nokkonen/services/<name> module prefix, tied together by a top-level go.work for local development. The shared module holds the common MQTT-connect and wire helpers used across the services.

Services at a glance

• state-machine: the hub. Subscribes to all ingest/meta/ack topics, persists to SQLite (schema via services/state-machine/migrations/), serves a dashboard (default :8080), publishes Home Assistant MQTT discovery, and drives machine control, WoL, and ping. Config via env (MQTT_BROKER, DB_PATH, WEB_ADDR, WEB_BASE_URL, ...).

  It is also the FOTA control plane: upload a firmware binary, sign it with the server's Ed25519 key, and push an over-the-air update to a single device or to a whole firmware group in bulk, tracking each device's OTA ack. Only signed firmware can be pushed.

• machine-monitor: runs on each Linux host. Reports thermals/fans/disk/ load/mem, and - only when locally configured CONTROLLABLE=true - accepts reboot/shutdown. The host's own config is the source of truth: a report-only box (the default) rejects all control commands regardless of what the hub sends. See its DEPLOY.md for the polkit setup controllable hosts need.

• wol-helper: one always-on LAN box. Turns MQTT requests into Wake-on-LAN magic packets, and ICMP-pings machines (via the system ping) so the hub can tell "shut down" from "alive but not reporting".

• ble-ingest / ld-2450-ingest / bme-680-ingest: bridge local hardware (BLE sensors, LD2450 serial radar, BME680 I2C environmental sensor) onto the MQTT ingest topics. bme-680-ingest publishes onto the shared env topic like ble-ingest, adding barometric pressure, gas resistance, and (after a gas burn-in) an approximate air-quality index.

Running

Requires Go 1.26+ and a Mosquitto broker configured with the files in infra/mosquitto/ (password auth + ACLs; add a mosquitto_passwd entry per service/device username).

Build any service from its directory:

cd services/state-machine && go build ./

Each service ships a systemd unit and a DEPLOY.md with step-by-step cross-compile, install, and configuration instructions.