About Coldframe

Architecture

Each sensor node sends readings as JSON over HTTP every 60 seconds. The Sensor API broadcasts live data over WebSocket and writes to long-term storage hourly. The dashboard consumes both streams: live data on the Feeds page and historical data on the Trends page.

Data Journey

Sensors

Step 1 / 6

Microcontroller → Wi-Fi

protocol: WiFiClientSecure

{
  ssid: "MyNetwork",
  ipAssigned: "192.168.0.105"
}

The ESP32 connects to Wi-Fi using WiFiClientSecure. Once it receives an IP it stays online and sends readings over HTTPS.

Alerting

Step 1 / 5

Sensor API → Alert Service

Internal pub/sub

{
  sensorId:    "cf-001",
  timestamp:    "2026-05-20 14:00",
  temperatureC: 44.0,
  humidityPct:  54.1,
  pressureHPa:  1008.6
}

Every POST to /api/sensor emits a reading on the internal event bus that the alert service subscribes to.

System Components