Tag: Breathe2

Current placements of Breathe2 devices (Updated 18th Oct. 2019)

Subir / / Breathe2

IMD, Shivaji Nagar, Pune

– Mass,  number and ambient conditions

Example of PM2.5 live data –

Samuchit Enviro Tech Pvt. Ltd., Law college road, Pune

– Mass,  number and ambient conditions

Example of PM2.5 live data –

Near Indradhanushya Hall,  Rajendra Nagar, Pune.

– Mass,  number and ambient conditions

Example of PM2.5 live data –

Near Bapat Hospital, Model Colony, Pune

– Mass,  number and ambient conditions

Example of PM2.5 live data –

MIT College, Kothrud, Pune

– Mass,  number and ambient conditions

Example of PM2.5 live data –

All the data can be downloaded as a single CSV file from each channel. Here’s how:

  1. Identify which channel you wish to analyze for which device. Each device outputs 3 channels
    1. Mass concentrations of  – PM1, PM2.5, PM4 and PM10
    2. Number concentrations of – PM0.5, PM1, PM2.5, PM4 and PM10
    3. Ambient conditions – Relative Humidity (%), temperature (deg. C), and pressure (Pa)
  2. The channel number is the one at top left corner of the page (which opens when you click any of the mass, number and ambient conditions links) by name of “Channel ID”.
  3. Copy and paste the following command on any internet browser, and replace the <channel_ID> with the channel id you recovered from step 2 –
    1. https://api.thingspeak.com/channels/<channel_ID>/feeds.csv?results=8000
  4. This will download a csv file.

Major Flaw in Breathe2 V1 design

Subir / / Breathe2

After months of exposure to Shivajinagar’s traffic and running on a 12V fan 24×7 (or whenever the mood was not bad), here’s the dust settlement on the original version’s innards.

Intake and exit points of the SPS30 PM sensor.

Dust on SIM800 module which is way at the end of the air path.

All over the board there’s dust.

Another view of the dust on the SPS30 sensor.

So it proves that this design is bad at the fundamental level. This amount of dust, and expected condensation will definitely cause some shorting someday. The newest design Breathe2 V1.2 bypasses this condition by shielding the external environment from the components. Only the underside of the PCB (where there are no components except a LED) is exposed.

Breathe2 V1.1

Subir / / Breathe2

V1.1 was designed to fit into a cap of a PVC pipe and all this held upside down so that the cap is on top. The gaps in the PCB would allow the air sensor to get fresh air and so on. The PCB would have a dual task as a PCB and of keeping the components mounted on it from being exposed to external weather conditions.

A populated V1.1 board and its bottom with our name and version.

However, the biggest mistake (Subir’s) was the selection of the power supplies MP1584 (see the 5V written by hand on the left disc) which ran hot within a few minutes leading to resetting of the boards.

10 PCBs were made, some were populated, but due to the fundamental problem of power supply, all this had to be scrapped.

Prototype V1 (Created – 25th Apr 2019)

Subir / / Breathe2 
Inspired by Breathe device network of IndiaSpend.com

Aim:

Make a low cost but decent performance air quality monitoring device that can upload real-time data to the web for city-scale geographic analysis of air pollution.

Breathe2 Features:

 

Where is it installed:

For testing and calibration purposes Prototype1 has been installed about 10m away from the government’s SAFAR device situated at Indian Meteorological Department (IMD) Office (Shimla Office as known in Pune) at Shivajinagar, Pune.

Live data:

 

Physical structure overview

Challenges / next steps:

  • Verify if Particulate Matter (PM) data is similar to SAFAR data from Govt. of India.
  • See if device can withstand harsh external conditions such as thunderstorms, heat waves and dew condensation conditions.
  • See if device has repeatability over various environmental conditions.
  • Develop robust web-services for collection, analysis and public display of data.
  • Dream: Add a noise sensor to device.

 

Team:

  1. Abhijeet Savant
  2. Subir Bhaduri
  3. Mayuresh Kulkarni