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7Semi SHT45 and SGP41 Environmental Sensor Breakout

7Semi SHT45 and SGP41 Environmental Sensor Breakout

₹1,174.00Price
🔍 Overview
This breakout combines two advanced sensors:
  • Sensirion SHT45 temperature and humidity sensor
  • Sensirion SGP41 VOC and NOx gas sensor
👉 It is a multi-parameter environmental sensing module capable of measuring:
  • Temperature
  • Relative Humidity
  • Volatile Organic Compounds (VOC)
  • Nitrogen Oxides (NOx)
⚙️ Working Principle
🌡️ Temperature & Humidity (SHT45)
Temperature
  • Uses bandgap temperature sensing
  • Provides highly accurate temperature readings
Humidity
  • Uses capacitive polymer sensing
  • Moisture absorption changes capacitance
  • Converted to digital RH value
👉 Outputs are factory calibrated and digitally processed.
🧪 Gas Sensing (SGP41)
VOC / NOx Detection
  • Uses MOX (Metal-Oxide) gas sensing technology
  • Includes:
    • Micro-heater
    • Gas-sensitive layer
Operation
  • Heater activates sensing layer
  • VOC/NOx gases interact with surface
  • Resistance changes
  • Converted into digital signal
👉 Provides air quality indices (raw signals + processed outputs).
📊 Measurement Characteristics
🌡️ SHT45
  • Temperature:
    • Range: −40°C to +125°C
    • Accuracy: ±0.1°C (typical)
  • Humidity:
    • Range: 0–100% RH
    • Accuracy: ±1.0% RH (typical)
🧪 SGP41
  • VOC index (relative scale)
  • NOx index (relative scale)
  • Requires humidity compensation for best accuracy
👉 Combined system provides complete indoor air quality monitoring.
⚡ Electrical Characteristics
  • Supply voltage: 1.7V to 3.6V
  • Low power consumption overall
  • SGP41 consumes more due to heater cycles
🔗 Communication Interface
  • Interface: I²C (shared bus)
  • Typical addresses:
    • SHT45: 0x44
    • SGP41: 0x59
👉 Both sensors operate independently but share the same I²C lines.
🧠 Internal Features
✔ Environmental Compensation
  • SGP41 uses:
    • Temperature
    • Humidity data (from SHT45)
  • Improves gas measurement accuracy
✔ Digital Output
  • Fully processed data:
    • °C
    • %RH
    • VOC index
    • NOx index
✔ Integrated Heater (SGP41)
  • Enables gas sensing
  • Requires controlled operation cycles
✔ High Stability & Low Drift
  • Suitable for long-term monitoring
🔄 Operating Behavior
✔ Multi-Sensor Coordination
  • Temperature & humidity readings:
    • Used to compensate gas sensor output
✔ Continuous Monitoring
  • Periodic measurement cycles:
    • Fast response for environmental changes
✔ Air Quality Trends
  • VOC/NOx values represent:
    • Relative air quality changes
🌡️ Environmental Characteristics
  • Wide operating range:
    • Temperature: −40°C to +125°C
    • Humidity: 0–100% RH
⚠️ Limitations
  • VOC/NOx outputs are:
    • Relative indices (not exact ppm values)
  • Gas sensor sensitive to:
    • Humidity
    • Temperature
    • Airflow
  • Requires:
    • Calibration algorithms for best results
🧩 Breakout Board Role (7Semi)
The breakout board:
  • Integrates both sensors on one PCB
  • Provides:
    • I²C interface access
    • Power regulation support
  • Simplifies multi-parameter sensing
🏁 Summary
The 7Semi SHT45 + SGP41 breakout is a comprehensive environmental sensing module that:
  • Measures temperature and humidity with high precision
  • Detects VOC and NOx gases using MOX technology
  • Uses sensor fusion for improved accuracy
  • Provides digital I²C output
  • Enables indoor air quality monitoring in a compact design
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