A CO₂ monitor with optional Home Assistant and InfluxDB integration implemented in NodeMCU / Lua. It shows the current CO₂ concentration and MH-Z19 temperature on a 128×32 SSD1306 OLED; optionally making them available to Home Assistant via MQTT or to InfluxDB via HTTP.

Features

• Display for CO₂ and temperature
• Optional Home Assistant integration via MQTT
• Optional logging to InfluxDB
• Powered via USB

Components

• Processor: ESP8266
• CO₂ sensor: MH-Z19
• Display: 128×32 OLED via SSD1306 (128×64 also supported with some changes)

Images