Overview
An ultra-low-power environmental monitor for a home kitchen, built on an ESP32 LOLIN32. It tracks combustible gas, temperature and humidity, wakes on motion, and sleeps again to save battery.
Core features
- Combustible gas and smoke measured through an analog MQ-2 module
- Climate monitoring of temperature and relative humidity with a DHT22
- On-demand activation: the device wakes only when the PIR detects motion
- Live readings on a 16x2 character LCD over I2C
- Deep sleep after 20 seconds without motion, woken by an RTC GPIO interrupt
- Battery operation from a single LiPo cell
In this project
| Chapter | What it covers |
|---|---|
| Source repository | repository link, layout, build commands |
| System architecture | block diagram, state machine, signal flow |
| Hardware | full pin map, wiring and power notes |
| ESP32 LOLIN32 and pin configuration | board resources and the pins in use |
| MQ-2 gas and smoke sensing | analog reading and interpretation |
| DHT22 climate monitoring | 1-Wire protocol and sampling |
| PIR motion sensing and wakeup | interrupt source and debounce |
| 16x2 I2C display interface | addressing, backlight, display format |
| Low-power and deep sleep architecture | wake sources and the idle window |
| Firmware build and architecture | PlatformIO setup and dependencies |
| Results | what works, and what is not measured |
| Diagnostics and debugging guide | serial logs and sensor checks |