Air Quality Bricklet

Features

  • Measures IAQ (indoor air quality) index, air pressure, humidity and temperature
  • IAQ index and humidity values are temperature compensated
  • Configurable temperature compensation for use cases in enclosures

Description

The Air Quality Bricklet can measure

  • IAQ (indoor air quality) index,
  • Air pressure in mbar,
  • Humidity in %RH and
  • Temperature in °C.

The IAQ index is a measurement for the quality of air. To calculate the IAQ index the Bricklet detects ethane, isoprene (2-methylbuta-1,3-diene), ethanol, acetone and carbon monoxide (often called VOC, volatile organic components) by adsorption. These gas measurements are combined with the measurements of air pressure, humidity and temperature to calculate the final IAQ index.

The IAQ index has a range of 0-500:

IAQ index scale

Typical applications for this Bricklet are the monitoring of air quality, environmental statistics, home automation and similar.

The Air Quality Bricklet has a 7 pole Bricklet connector and is connected to a Brick with a 7p-10p Bricklet cable.

Technical Specifications

Property Value
Sensor BME680
Current Consumption 100mW (20mA at 5V)
   
IAQ Index Resolution 1
Air Pressure Resolution 0.0018mbar
Humidity Resolution 0.008%RH
Temperature Resolution 0.01°C
IAQ Index Accuracy ±15 and ±15% of reading
Air Pressure Accuracy ±0.12mbar (700-900mbar at 25-40°C), ±0.6mbar (full scale)
Humidity Accuracy ±3%RH (20-80%RH at 25°C)
Temperature Accuracy ±0.5°C (at 25°C), ±1.0°C (0-65°C)*
Measurement Frequency 0.3 measurements per second
   
Dimensions (W x D x H) 25 x 20 x 5mm (0.98 x 0.79 x 0.19")
Weight 2.1g

* This is the temperature at the exact position of the sensor. If the Bricklet is used inside of an enclosure, the air around the Bricklet may heat up more than the ambient air. The Bricklet does have API to calibrate this kind of offset.

Calibration of the temperature value is recommended, since the temperature value is used to compensate the IAQ index and humidity values.

Resources

IAQ Index Accuracy

The Bricklet is building a database of measurements and uses this data to calculate an accurate IAQ index over time. It will take 1-2 days until the IAQ index has a high reliability. The API of the Bricklet returns a best guess about the accuracy (ranging from unreliable to high).

The Bricklet saves the current database of values and calculated coefficients every 12 hours in its internal flash memory. If the Bricklet loses power it will not take as long to receive reliable data again.

Test your Air Quality Bricklet

To test a Air Quality Bricklet you need to have Brick Daemon and Brick Viewer installed. Brick Daemon acts as a proxy between the USB interface of the Bricks and the API bindings. Brick Viewer connects to Brick Daemon. It helps to figure out basic information about the connected Bricks and Bricklets and allows to test them.

Connect the Air Quality Bricklet to a Brick with a Bricklet Cable.

If you connect the Brick to the PC over USB, you should see a new tab named "Air Quality Bricklet" in the Brick Viewer after a moment. Select this tab. If everything went as expected you can now see the values for IAQ index, air pressure, humidity and temperature.

Air Quality Bricklet in Brick Viewer

After this test you can go on with writing your own application. See the Programming Interface section for the API of the Air Quality Bricklet and examples in different programming languages.

Case

A laser-cut case for the Air Quality Bricklet is available.

Case for Air Quality Bricklet

The assembly is easiest if you follow the following steps:

  • Screw spacers to the Bricklet,
  • screw bottom plate to bottom spacers,
  • build up side plates,
  • plug side plates into bottom plate and
  • screw top plate to top spacers.

Below you can see an exploded assembly drawing of the Air Quality Bricklet case:

Exploded assembly drawing for Air Quality Bricklet

Hint: There is a protective film on both sides of the plates, you have to remove it before assembly.

Programming Interface

See Programming Interface for a detailed description.

Language API Examples Installation
C/C++ API Examples Installation
C# API Examples Installation
Delphi/Lazarus API Examples Installation
Java API Examples Installation
JavaScript API Examples Installation
LabVIEW API Examples Installation
Mathematica API Examples Installation
MATLAB/Octave API Examples Installation
Perl API Examples Installation
PHP API Examples Installation
Python API Examples Installation
Ruby API Examples Installation
Shell API Examples Installation
Visual Basic .NET API Examples Installation
TCP/IP API    
Modbus API