SCD40 I2C CO Temperature & Humidity Sensor Breakout Module - 7Semi

🔍 What this module is
The SCD40 CO2, Temperature and Humidity Sensor Breakout I2C is a 3-in-1 environmental sensor that measures:
🌬️ CO₂ (Carbon Dioxide)
🌡️ Temperature
💧 Humidity
It’s based on Sensirion’s SCD40 sensor, using photoacoustic (NDIR-like) technology for accurate CO₂ sensing.
⚙️ Key Specifications
CO₂ range: 400 ppm → up to 40,000 ppm (best accuracy: 400–2000 ppm)
Accuracy: ±(40–50 ppm + 5%)
Interface: I²C (easy for Arduino/ESP32/RPi)
Operating voltage: ~3.3V
Power consumption:
~17 mA (fast measurement)
~0.5 mA (low-power mode)
Integrated sensors: Temperature + Relative Humidity
🧠 Key Features
✔️ True CO₂ sensing (not eCO₂) – more accurate than MQ-series
✔️ Factory calibrated – plug & play
✔️ Low power – ideal for battery IoT
✔️ Compact size – easy to embed
✔️ Long-term stability – minimal recalibration needed
🔌 Pinout (Typical)
VCC → 3.3V
GND → Ground
SDA → I2C Data
SCL → I2C Clock
👉 I2C address: usually 0x62
💡 Applications
Indoor air quality monitors
Smart HVAC / ventilation control
Smart homes & IoT
Greenhouses / agriculture
Office CO₂ monitoring
⚠️ Important Notes (very useful)
⚠️ Not for outdoor harsh environments (best indoors)
⚠️ Auto-calibration may shift readings if room never reaches fresh-air (~400 ppm)
⚠️ Needs airflow exposure for accurate readings
🆚 Why SCD40 is popular
Compared to cheap sensors (like MQ135):
Much more accurate & stable
Gives actual CO₂ ppm
Lower drift over time
👍 When you should use it
Use this if you want:
Professional-quality air monitoring
Reliable CO₂ data for automation
Smart IoT environmental systems