Arduino Nano-based household hazardous gas alarm DIY kit

This is a DIY kit for a household hazardous gas alarm based on the Arduino Nano microcontroller. Designed as a STEAM educational product, it targets programming beginners, K-12 students, and electronics enthusiasts. The kit integrates multiple MQ gas sensors; by assembling the wiring and uploading open-source code, users can build a demonstration device capable of detecting various hazardous and combustible gases with both audible and visual alarms. It allows users to learn microcontroller programming and sensor detection principles through hands-on construction.

Why choose this hazardous gas alarm DIY kit?

1. Simultaneous 3-channel gas detection: Equipped with three MQ-series sensors, it can detect a wide range of combustible and hazardous gases, including carbon monoxide, LPG, natural gas, town gas, ammonia, sulfides, and benzene vapors.
2. Audible and visual alarms: A tri-color status indicator distinguishes between normal, warning, and danger (exceeding limit) states. An onboard buzzer triggers an alarm when gas concentrations exceed safe levels, providing intuitive feedback.

3. Open-source nano programming: Powered by the Arduino Nano, the kit includes open-source example code and supports custom programming to modify thresholds and logic—ideal for beginners learning C language programming and sensor principles.
4. Transparent acrylic enclosure: The see-through casing reveals internal circuitry and sensor wiring, making it easy to observe and understand the circuit structure. The finished product looks neat and is suitable for display.
5. USB power supply: Powered by DC 5V via USB; it can run off a computer USB port or a portable power bank, offering flexibility for various experimental settings.

Application scenarios:

1. Maker education / school training: Suitable for K-12 STEAM courses, information technology classes, and extracurricular clubs to teach sensors, analog signal acquisition, and microcontroller programming.
2. Student science & tech competitions: Ideal for entries in youth science innovation contests and robotics competitions, specifically for projects involving gas detection.
3. Electronics enthusiast DIY: Great for microcontroller practice, learning MQ gas sensor principles, and secondary development for IoT monitoring projects.
4. Science education & demonstrations: Useful for science museums and educational events to demonstrate gas detection principles, or as a fun science-based DIY project for parents and children to do together.

Precautions:

1. Sensor warm-up: The gas sensor requires a warm-up period to stabilize readings; initial value drift upon power-up is normal.
2. Testing environment: Do not conduct long-term testing in environments with high concentrations of corrosive or highly irritating gases, as this can damage the sensor and shorten its lifespan. Prevent dust or oil from accumulating on the sensor probe.
3. Power supply Requirements: Use a stable 5V USB power source; unstable voltage may cause abnormal readings or false alarms. Do not connect to a power source exceeding 5V, as this could burn out the main controller and sensor.
4. Safety warning: Strictly prohibit using the kit to directly test high-pressure gas pipelines or high concentrations of flammable/explosive gases, as this poses a risk of fire or explosion.
5. Storage: Disconnect the power if the device will not be used for an extended period. Store in a dry, well-ventilated area to prevent moisture from corroding the circuit board.