What you’ll learn:
- Why air quality matters in building automation, and the features of MOX technology.
- How easily ScioSense’s ENS161 sensor fits into a building automation system.
Building automation is revolutionizing the way we interact with our environments, offering seamless control, efficiency, and comfort at our fingertips. Within the sphere of building automation and intelligent housing, everyone is racing to embrace cutting-edge technologies and maximize energy efficiency. However, one crucial aspect often gets left behind: indoor air quality and the potential risks it poses.
Given that people spend most of their time indoors, improving indoor air quality is essential for public health. Recent studies on indoor air quality have highlighted the concerning reality that many individuals are consistently exposed to a cocktail of gases. While not immediately life-threatening, these gases can have negative consequences over time, potentially leading to various health issues.
When indoor air isn’t sufficiently ventilated, contaminants build up, negatively impacting our health, but also reducing our ability to recall information and maintain productivity. From building materials to everyday activities like cooking, our indoor spaces are inundated with volatile organic compounds (VOCs), an ever-present yet invisible threat, often ignored or underestimated by most individuals.
No need to worry, though, because there’s a straightforward solution: metal oxide technology (MOX). Embracing efficient ventilation technologies isn’t just about creating comfortable indoor environments. It’s about safeguarding our planet’s health and our wallet.
Effortless Integration and Optimal Performance
In the context of the smart building, the MOX sensor emerges as an ideal solution. Composed of a metal oxide layer on a sensing chip and a heater underneath, the sensor’s MOX changes its electrical resistance depending on the ambient gas concentration, from which the air quality can be derived. Among the available MOX technologies, ScioSense’s ENS161 sensor requires minimal integration effort both at the hardware and software levels.
The ENS161 is a low-power-consumption but powerful device supporting improved and intelligent algorithms to turn raw data into total VOC (eTVOC), equivalent CO2 (eCO2), and additional air-quality indices, without any special experience or knowledge needed by the end-user. These real-time outputs allow for proactive adjustments to ventilation settings, ensuring a consistently healthy indoor environment based on your occupancy needs. Furthermore, its algorithm has recently been optimized specifically for home and building automation (HaBa) applications.
Integration of ENS161 in HaBa Applications
Beginning with electrical, followed by mechanical integration, recommendations are provided to ensure a clear and systematic process and address the invisible threats of your smart building.
Circuit design (Fig. 1):
- The sensor can communicate through I2C or SPI.
- The minimum supply voltage VDD is 1.71 V; it must not drop below this value to ensure reliable operation. A good power supply decoupling is recommended; therefore, decoupling capacitors need to be placed near pins 4 (VDD) and 5 (VDDIO), respectively 10 µF and 100 nF. VDDIO is the interface supply pins, i.e., 3.3 V.
- If using I2C communication, pin 7 (CSn) must be pulled high to select I2C mode, while pin 3 (MISO/ADDR) should be pulled low or high to specify the address LSB. “High” refers to VDDIO. In case of SPI, see the above circuit.
- In a test setup, when configuring the operational mode, please take care of proper contacts. Transient resistance from jumper wires could introduce a momentary drop in resistance and, therefore, a resulting current drop, potentially causing a reset in ENS161.
- Remember that the sensor operates at 1.8 V. Thus, if you have a typical 3.3-V or higher voltage source, it requires the introduction of a linear voltage regulator or a DC switching voltage regulator.
