Measure the air quality in your backyard


Zymbit is measuring the air quality underneath a flight path with a custom sensor board, Arduino Zero and Raspberry Pi. 


Our friends at Zymbit are located in Santa Barbara, not too far from the county’s municipal airport. Residents of their local community were a bit concerned over how flight patterns overhead affected their environment and overall health. And so, the team decided to develop a system to easily monitor the air quality in their backyards to determine once and for all if their well-being was, in fact, was impacted by airplane departures and arrivals.

Airplane

For this project, Zymbit built and deployed five air quality stations, each tasked with measuring different air quality parameters using the combination of commercial grade sensors, Raspberry Pi and Arduino. These units were then connected through Zymbit’s proprietary software to generate real-time charts. The data is further integrated into environmental analysis software from Groundswell Technologies, too. This allows the Santa Barbara residents to essentially “see the air they breathe.”

The complete system is attached to a modified solar radiation shield crowned with an IP67 enclosure, while all the sensors are mounted to a custom motherboard. Sensor data is acquired using an Arduino Zero (Atmel | SMART SAM D21) located within the top tier of the radiation shield. From there, data is packaged and sent to a Raspberry Pi via a serial connection, which is external to its waterproof IP65 housing. As Zymbit notes, this way the heat is properly dissipated and does not affect sensor measurements.

Air-Quality-in-My-Back-Yard-Graphic-3

Meanwhile, the Raspberry Pi acts as the connection gateway and publishes the packaged data to zymbit.com/console. For immediate purposes, data flow is unidirectional — meaning, the unit is not subscribing to any outside streams, though this could easily be integrated. Additionally, with room to spare in the Raspberry Pi enclosure, the Zymbit crew added a PoE (Power Over Ethernet) splitter for versatility. This makes installation simple and improves overall reliability since the unit only requires a single cable connection and POE can handle wide line voltage variations. The user can then choose either a Wi-Fi or Ethernet connection. Of course, a USB cable will also work to power the unit.

At the heart of the air quality station lies a custom designed sensor board that integrates multiple sensor types, such as particulate matter, carbon dioxide, relative humidity, temperature and barometric pressure.

Air-sensor-board_in-hand_1

“The particulate sensor was the primary driver for the board’s design; it uses a small convection heater to circulate air and this requires the module to be oriented vertically,” Zymbit’s Evan Fairchild explains. “The particulate matter sensor has two channels; one for ~ 2.5 micron particles and one for ~ 10 micron particles. Each channel produces pulses which are measured and accumulated over thirty second intervals. The other sensors are managed via I2c bus and are all averaged over 15 second intervals.”

Once data is published, it is stored in the Zymbit Cloud. There, it is easy to interact with using instant dashboards or the Zymbit API. For this application, the engineers at Groundswell Technologies — who also collaborated on this project — utilized the API to pull the raw data into their analysis and visualization software.

At the moment, five Zymbit air quality stations have been successfully deployed and are active in their area of interest. Impressively, each unit only required less than an hour to install and to begin receiving data.

“Data streams from each unit are now being integrated into Groundswell’s geospatial software,” its creators add.

pm25-24h

Zymbit hardware is self-contained and designed to operate outdoors in a nominally shaded area. For the initial pilot, connection to the Internet is established via Wi-Fi or Ethernet to host building gateway/router. For subsequent projects, Zymbit has plans to provide options for solar power and cellular connection.

Interested? You can find all of the real-time data here, and learn all about the project on its official page.

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