HOW DOES IT WORK?

Environment 4 Click is based on the SHT41A-AD1B and SGP41, a 4th-generation high-accuracy SHT relative humidity, and a temperature sensor combined with MOx based gas sensor from Sensirion. Based on Sensirion's proven CMOSens® Technology and longstanding experience in humidity sensing, the SHT41A-AD1B ensures the highest precision. It covers extended operating humidity, and temperature ranges from 0 to 100%RH and from -40°C to 125°C with accuracies of ±2%RH and ±0.3°C. The SHT41A-AD1B also specializes in automotive applications, fulfilling reliability requirements such as 85°C/85%RH accelerated life tests and AEC Q100 qualification.

The SHT41A-AD1B shows the best performance when operated within the recommended average temperature and humidity range of 5-60°C and 20-80%RH. Long-term exposure to conditions outside recommended normal range, especially at high relative humidity, may temporarily offset the RH signal. After returning to the recommended average temperature and humidity range, the sensor will recover to within specifications. An additional part of this combo solution represents the SGP41, Sensirion's new MOx-based gas sensor, providing one VOC and one NOx-based indoor air quality signal.

As mentioned, the SGP41 provides two raw digital signals sensitive to most VOCs, typically present in indoor environments and oxidizing gases such as NOx or O3. This feature also makes this board well-suited for constantly monitoring the VOC and NOx situation, including potentially harmful events which humans do not perceive. The raw signals are proportional to the logarithm of the resistance of the sensing material and are processed by Sensirion's mighty Gas Index Algorithm. It can be directly used to automatically trigger the removal of indoor air gas pollutants by air treatment devices without requiring a user–device interaction.

Environment 4 Click communicates with MCU using the standard I2C 2-Wire interface. Since both sensors for operation require only a 3.3V logic voltage level, this Click board™ also features the PCA9306 voltage-level translator from Texas Instruments. The I2C interface bus lines are routed to the dual bidirectional voltage-level translator, allowing this Click board™ to work appropriately with both 3.3V and 5V MCUs.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

SPECIFICATIONS