Side Projects – Air Quality Sensor

As we have all been acutely aware the past few weeks, the air quality in the Bay Area has been abysmal at times due to the various wildfires. The smoke blanketing the area was the product of 10,000 buildings, and the nearly 100 people that perished. This was not just ordinary wood fire smoke. It was full of all kinds of nasty particulates, carcinogens, and burned over areas that previously contained radioactive waste. Not good. You could go to sites like airnow.gov to see what is going on regionally. But what about in your area specifically? Or even in your home? There are actually very few sensors in South County. One solution is purpleair.com which is a network of personally or corporate sponsored sensors. But they are again, expensive, around $250 or more with shipping.

There are certain benefits to these more expensive sensors. They typically have additional data like temperature, barometric pressure, and humidity. They also use dual sensors in a parity configuration to help ensure accuracy. But what if you don’t really need all that?

So why not build your own? For about $70 and a couple hours of your time, you can assemble the components and get a fairly good quality particulate sensor up and running for your home or office. You can get output that looks similar to this:

Current N6DZK air quality: PM1.0: 3ug/m3, PM2.5: 6ug/m3, PM10: 9ug/m3, PM2.5 AQI index 25 (good)

Electric Imp is a company that enables IOT (Internet of Things). They are based here in the Bay Area, and naturally were also impacted by the air quality crisis at the time. I have built projects with their products before. They have proven to be extremely reliable, with one project having been online for several years now. Over on their blog, their CEO and co-founder, Hugo Fiennes, published a post on how to build your own AQI sensor using their card, and a little development breakout board, and a sensor from Amazon.  So, why not? I ordered up the parts, and 3 days later assembled them together, ran the provided code, and had a working sensor telling me how dirty my home office air really is (turns out it was actually not that bad).

Follow the directions on the blog post. It is not much to look at, but it does get the job done for a fraction of the cost of commercial versions. And you can then alter the web page to look like anything you wish. It is cloud hosted, no local server to run or deal with. And Electric Imp has proven to be a robust, reliable, long term solution.

There are some intermediary steps that someone new to Electric Imp will have to complete prior to getting your sensor online. You will need to create an account, download the app to your phone that programs the Imp device to get on your home WiFi, and a few other minor steps. But Imp devices are remarkably easy to get up and running.

Enjoy!

 

Category: DIY