Air quality 9 Click is a compact add-on board containing a best-in-class air-quality sensing solution. This board features the ENS160, a digital multi-gas sensor solution based on metal oxide (MOX) technology with four MOx sensor elements from ScioSense. Each sensor element has independent hotplate control to detect a wide range of gases. The ENS160 series features TrueVOC™ air quality detection and supports intelligent algorithms, which calculate CO2 equivalents, TVOC, air quality index (AQI), and perform humidity and temperature compensation. This Click board™ is interface-configurable and characterized by outstanding long-term stability and lifetime. This Click board™ makes an excellent choice for detecting unhealthy air conditions, such as personal air-quality monitors, HVAC, smart thermostats, and other air quality-related applications.

Air quality 9 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

Air quality 9 Click as its foundation uses the ENS160, an indoor air quality sensor based on metal oxide (MOX) technology with four MOx sensor elements from ScioSense. This sensor comes with sophisticated sensor fusion algorithms to produce measurement outputs that are better tuned to the natural response of human occupants. The multi-element TrueVOC™ technology, on which the ENS160 is based, is sensitive to oxidizing gases such as ozone which affect the quality of indoor air, as well as to a wide range of volatile organic compounds (VOCs) such as ethanol, toluene, as well as hydrogen and nitrogen dioxide with superior selectivity and accuracy. The ENS160 complies with worldwide Indoor Air quality (IAQ) signal standards and is designed for high volume and reliability.

For best performance, the sensor needs to be operated in normal indoor air in the range -5 to 60°C (typical: 25°C), while relative humidity ranges from 20 to 80%RH (typical: 50%RH), non-condensing with no aggressive or poisonous gases present. Prolonged exposure to environments outside these conditions can affect the performance and lifetime of the sensor.

This Click board™ allows using both I2C and SPI interfaces with a maximum frequency of 1MHz for I2C and 10MHz for SPI communication. The selection can be made by positioning SMD jumpers labeled as COMM SEL to an appropriate position. Note that all the jumpers' positions must be on the same side, or the Click board™ may become unresponsive. While the I2C interface is selected, the ENS160 allows choosing the least significant bit (LSB) of its I2C peripheral address using the SMD jumper labeled ADDR SEL. This Click board™ also possesses an additional interrupt signal, routed on the INT pin of the mikroBUS™ socket labeled as INT, indicating the status of the measurement process itself.

The ENS160 also requires a supply voltage of 1.8V to work regularly. Therefore, a small LDO regulator, AP2112 from Diodes Incorporated, provides a 1.8V out of mikroBUS™ 3V3 power rail. This LDO can be enabled or disabled through the EN pin routed to the PWM pin of the mikroBUS™ socket; hence, offering a switch operation to turn ON/OFF power delivery to the ENS160.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

• Interface: I²C, SPI
• Compatibility: mikroBUS™
• Dimensions: 28.6 x 25.4mm
• Input Voltage: 3.3V
• TVOC: Min. 0ppb, Max. 65.000ppb
• eCO₂: Min. 400 ppm CO₂, Max. 65.000 ppm CO₂
• Operating Humidity Range: Min. -5%RH, Typ. 50%RH, Max. 85%RH
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +85°C

• Schematic
• AP2112 Datasheet
• ENS160 Datasheet
• mikroSDK
• LibStock