CO2 Sensor

Hardware

Development board M5StickC Plus
Sensor MH-Z19B

Features

CO2 (Carbon dioxide) level continuous output (400-5000 ppm)
Temperature output (internal sensor)
24h history chart available from built-in Web server
CO2 alarming using built-in LED
Day/Night screen mode
Current and 3h forecast weather

Dev Environment

Project uses PlatformIO IDE targeting Espressiff's ESP32 and Arduino framework.

Configuration

Wifi SSID name and password to access weather and NTP
Timezone (in seconds, e.g., 3600 for UTC+1)
NTP Server name (e.g., europe.pool.ntp.org)
CO2 alarm threshold (e.g., 1000)
City and API Key to read data from openweathermap.org

User Manual

On first power on devices need to be configured. Connect to "CO2_Sensor" Wi-Fi AP and then go to http://192.168.1.1. Edit configuration and confirm with Update button. After devices rebooted you should see current CO2 measure, temperature, current weather and 3h forecast.

To see sensor values history, go to device IP or scan QR code that is available after pressing BtnA.

To reboot, press power button shortly.

To factory reset, use BtnA to switch display until "Factory?" shown. Confirm with button BtnB.

To edit settings, use BtnA to switch display until "Edit?" shown. Confirm with button BtnB.