Hello friends, in this project, we will learn, how to make security alarm by using Pir sensor and Arduino nano. I set 10 second time delay when system turn ON. After 10 second motion sensor detects motion, it sent signal to arduino nano and arduino nano turn ON the alarm for three seconds. You can change this time from code.
🛠️ เจาะลึกเบื้องหลังการทำงาน (Deep Dive / Technical Analysis)
The MQ-3 Alcohol Sensor is a specialized tool designed specifically to detect alcohol vapors in the air or on a person's breath. It's a fascinating way to learn about chemical sensing and gas concentration.
Detection Principle
Similar to other sensors in the MQ series, the MQ-3 uses a sensitive heating element (SnO2). In clean air, its conductivity is low. When alcohol vapors are present, the sensor's resistance drops significantly.
- Sensitivity: It can detect concentrations from 0.05 mg/L to 10 mg/L.
- The Output: The Arduino reads the analog signal and can be programmed to trigger different colored LEDs based on the concentration (e.g., Green for Low, Yellow for Medium, Red for High).
Hardware Components
- Arduino Uno/Nano: The processor.
- MQ-3 Alcohol Sensor Module: The primary hardware.
- LEDs (3 colors): To act as a visual bar graph.
- Buzzer: To sound an alarm at high concentrations.
Education vs Reality
While this project is a great way to learn about calibration curves and analog thresholds, it is important to remember that it is for educational purposes and should never be used as a professional breathalyzer for safety-critical tasks.