The 7Semi SCD40 CO₂, Temperature, and Humidity Sensor Breakout (I²C) is a compact and efficient environmental sensor module designed for accurate indoor air quality monitoring. Utilizing advanced photoacoustic NDIR technology, it measures CO₂ concentrations ranging from 400 to 2000 ppm with an accuracy of ±(50 ppm + 5% of reading). In addition to CO₂, it simultaneously measures ambient temperature and humidity, providing a comprehensive environmental profile. The sensor operates at 3.3V and communicates via I²C, making it compatible with popular microcontrollers like Arduino, ESP32, and Raspberry Pi. Its low power consumption (17 mA at 5-second intervals or 0.5 mA at 5-minute intervals) ensures suitability for battery-powered applications. Fully calibrated and linearized, the SCD40 offers long-term stability with minimal recalibration needs, making it ideal for smart home automation, HVAC systems, and IoT projects.