# MQ-7 CO Sensor

Day 33 of the 100 Days 100 IoT Projects collection. Board: ESP32.

Detect carbon monoxide with an MQ-7 on the ESP32 and raise an alarm. A focused safety build with real stakes.

## How it works

The MQ-7 runs heating cycles that make it sensitive to carbon monoxide, and the ESP32 watches its output for dangerous concentrations. Crossing the safety threshold latches the alarm on until levels fall. A focused build where getting the threshold right genuinely matters.

## What you'll learn

- CO sensor heating cycles
- Safety threshold design
- Alarm latching logic
- Gas sensor selectivity

Full project (code, wiring diagram, Wokwi simulation): https://github.com/kritishmohapatra/100_Days_100_IoT_Projects/tree/main/MQ7_CO_Gas_Detection_ESP32

Summary by SkillShop. Code and diagrams belong to the original repo.