The 7Semi STC42A + SHT40 Hydrogen, Temperature & Humidity Sensor Breakout is a compact, dual-sensor module designed to measure hydrogen concentration, relative humidity, and temperature. The STC42A uses thermal conductivity technology to measure hydrogen concentrations from 0 to 40 vol% in clean air, while the SHT40 provides accurate digital humidity and temperature measurements.
The onboard humidity and temperature sensor supplies environmental measurements that can be used to compensate hydrogen readings for changes in ambient conditions. The STC42A also supports automatic self-calibration to improve long-term measurement stability in suitable applications.
Featuring a compact 17 × 8 mm PCB, a Qwiic-compatible connector, and a 3.3V I2C interface, the breakout simplifies integration into hydrogen monitoring equipment, battery research, laboratory testing, and embedded sensing systems.
Key Features
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3-in-1 Environmental Sensing: Measures hydrogen concentration, relative humidity, and temperature using two integrated sensing devices.
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Hydrogen Measurement: Supports hydrogen concentration measurements from 0 to 40 vol% in clean air.
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Fast Hydrogen Response: Provides a typical hydrogen response time of approximately 1 second .
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High-Accuracy Humidity Sensing: Offers +/-1.8%RH typical accuracy across a 0–100%RH measurement range.
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Precise Temperature Measurement: Provides +/-0.2 C typical temperature accuracy.
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Humidity Compensation Support: Provides temperature and humidity measurements for compensation of hydrogen readings when correctly configured.
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Digital I²C Interface: Enables communication with compatible microcontrollers and embedded controllers.
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Low-Power Operation: Supports low-power measurement modes for energy-sensitive applications.
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Automatic Self-Calibration: Supports automatic zero-point adjustment to maintain long-term stability in applications where hydrogen is absent most of the time.
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Selectable I2C Address: Supports two I2C addresses, 0x29 (default) and 0x2A (alternate), selectable by removing the onboard solder jumper.
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Qwiic Connectivity: Features a four-pin Qwiic-compatible connector with 3V3, GND, SDA, and SCL connections.
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Compact Design: Features an approximately 17 × 8 mm PCB for space-constrained applications.
Product Includes
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1 × 7Semi STC42A + SHT40 Hydrogen, Temperature & Humidity Sensor Breakout
- Product Category:
- Hydrogen, Temperature & Humidity Sensor Breakout
- Sensor ICs:
- STC42A + SHT40
- Measurement Parameters:
- Hydrogen Concentration, Temperature, Relative Humidity
- Operating Voltage:
- 3.15 - 3.6 V DC
- Hydrogen Measurement Range:
- 0–40 vol% H₂ in Clean Air
- Hydrogen Response Time:
- Approximately 1 Second
- Temperature Measurement Accuracy:
- +/-0.2 C (Typical)
- Humidity Measurement Range:
- 0–100%RH
- Humidity Measurement Accuracy:
- +/-1.8%RH (Typical)
- Communication Interface:
- 0 to 100%RH
- Humidity measurement accuracy:
- I2C
- I2C Address:
- 0x29 (Default); remove the onboard solder jumper to select 0x2A.
- _resources_dxf:
- https://7semi.com/content/3d-files/dfx_step/10527.dxf
- _resources_step:
- https://7semi.com/content/3d-files/dfx_step/10527.STEP
- _resources_datasheet_file:
- https://7semi.com/content/datasheets/STC42_datasheet.pdf
- _summary:
- The 7Semi Sensor Breakout measures hydrogen concentration temperature, and relative humidity, with automatic humidity compensation.
- Operating Temperature:
- −40 C to +105 C
- Board Dimensions (L × W × H):
- 17 × 8 × 5 mm
