Air Quality Monitor I

The WeatherDuino Air Quality Monitor it very simple to build, and enables the user to measure PM2.5 and PM10 dust particles which are important measures of air pollution.
Based on the PM2.5 readings, and in accordance with EPA standards the Air Quality Index is computed by using Nowcast functions implemented in the WeatherDuino software.
Currently, two models of dust particle sensors are supported:

• PMS7003, from the well known brand Plantower.¹⁾
• Nova SDS011 made by Inovafitness.

Through the use of an optional MH-Z19 sensor, the Air Quality Monitor can also be used to monitor CO₂ levels in a room, greenhouse or outside.³⁾
The AQM (Air Quality Monitor) device can work in two different modes, simultaneously:

• First, as a transmitter to a WeatherDuino weather station²⁾ with Air Quality data, which can, in turn, be uploaded to WU, ThingSpeak or even to your own server for storage in a SQL database.
• Second, as an independent device that could be used by anyone, whether they have a WeatherDuino weather station or not.

In the Assembly Guide / Hints section below, we will explain how to set-up the AQM for each mode of use.

Example screen from an WeatherDuino Pro2 Compact receiver, showing Air Quality data, received from our Air Quality Monitor system.

Microcontroller: Arduino Nano
RF Frequency: 433Mhz or 315Mhz ⁴⁾
Dust Sensor: PMS7003 or Nova SDS011
CO2 Sensor: MH-Z19 (optional)
Power Requirements: 9VDC 1A power supply

• Get the Part List from here: WeatherDuino Pro2 & Pro2 PLUS - PCB and Parts lists
  
• Always buy the PMS7003 sensor with the adapter cable included.
• There are two versions of the MH-Z19 sensor, preferably choose the MH-Z19B version.

The Air Quality Monitor should be installed in a well-ventilated area outside the house, not exposed directly to elements such as rain, or direct sunlight.
A porch or a balcony is a good place to install it.
Choose an enclosure suitable for the environmental conditions where the AQM will be installed. If exposed to rain, the enclosure should be waterproof but allow air circulation.

¹⁾ - The very expensive PurpleAir Air Quality Monitor, uses an Plantower sensor (the PMS5003, older than PMS7003).
²⁾ - See systems compatibility here.
³⁾ - Precision measure of CO₂ concentration in open air, is a very complicated task, not achievable with simple equipment. According to specifications the error margin of an MH-Z19 sensor is +- 50ppm for indoor use, maybe more in outdoor use.
⁴⁾ - Must match the frequency used by other Transmitter units.