Internet of Smells: Giving a Machine the Job of Sniffing Out Spoiled Food

Has the food in your pantry turned? Sometimes it’s the sickening smell of rot that tells you there’s something amiss. But is there a way to catch this before it makes life unpleasant? If only there were machines that could smell spoiled food before it stinks up the whole place.

In early May, I was lucky enough to attend the fourth FabLab Asia Network Conference (Fan4). The theme of their event this year was ‘Co-Create a Better World’. One of the major features of the conference was that there were a number of projects featured, often from rural areas, that were requesting assistance throughout the course of the conference.

Overall there were many bright people tackling difficult problems with limited resources. This is how I met [Yogesh Kulkarni] who runs a FabLab in Pabal, a farming community not far from Pune, India. [Yogesh] has also appeared on TED Talks (video here). He explained to me that in his area, vendors sell milk-based desserts. These are not exactly refrigerated, and sometimes people become ill from eating them. It would be nice if there was a way for the vendors to avoid selling the occasional harmful product.

I’ve had similar concerns with food safety in my area (Vietnam), and while it has been fine nearly all of the time, a few years ago I nearly died from a preventable food-borne illness. I had sufficient motivation to do a little research.

Continue reading “Internet of Smells: Giving a Machine the Job of Sniffing Out Spoiled Food”

Monitoring Air Quality, One Sleepy Meeting At A Time

To those of us in the corporate world, the conference room is where hope goes to die. Crammed into a space too small for the number of invitees, the room soon glows with radiated body heat and the aromas of humans as the time from their last shower gradually increases. To say it’s not a recipe for productivity is an understatement at best.

Having suffered through too many of these soporific situations, [Charles Ouweland] took matters into his own hands and built this portable air quality meter for meetings. With an OLED display on top and sensors inside, it displays not only the temperature, humidity, and barometric pressure, but also the CO₂ concentration and the levels of volatile organic compounds (VOC), noxious substances sometimes off-gassed from building materials, furniture upholstery, and coworkers alike.

The monitor quantifies his meeting misery, which we’re sure wins him points with his colleagues. For our part, though, what we find interesting is his design process. He started where many of us would, with an Arduino Uno. The sensor modules, a CCS811 for VOC and CO₂ as well as a BME280 for temperature, humidity, and pressure, both needed 3.3 volts, so he added a regulator to knock the Arduino’s 5-volt supply into range and some MOSFETs for level matching. Things were getting bulky, though, so he set about reducing the component count. The Uno went by stripping out its already programmed MCU. That killed the need for the regulator and MOSFETs, since everything would be happy with 3.3 volts. A few more rounds of optimization led to the final product, compact enough to run on a pair of AA batteries.

This is a great lesson in going from prototype to product. And it’s so compact, it could even ride on top of a Roomba to map the conference room’s floor-level air quality.

Air Quality Surveillance for Whole Cities

Air quality is becoming a major issue these days, and not just for cities like Beijing and Los Angeles. It’s important for health, our environment, and our economy no matter where we live. To that end, [Radu] has been working on air quality monitors that will be widely deployed in order to give a high-resolution air quality picture, and he’s starting in his home city of Timisoara, Romania.

[Radu] built a similar device to measure background radiation (a 2014 Hackaday Prize Semifinalist), and another to measure air quality in several ways (a 2015 Hackaday Prize Finalist and a Best Product Finalist; winners will be announced next weekend). He is using the platforms as models for his new meter. The device will use a VOC air sensor and an optical dust sensor in a mobile unit connected to a car to gather data, and from that a heat map of air quality will be generated. There are also sensors for temperature, pressure, humidity, and background radiation. The backbone of the project is a smart phone which will upload the data to a server.

We’ve seen other air quality meters before as well, and even ones based around the Raspberry Pi,  but this one has a much broader range of data that it is acquiring. Its ability to be implemented as an array of sensors to gather data for an entire city is impressive as well. We can envision sensor networks installed on public transportation but to get to all parts of every neighborhood it would be interesting to team up with the Google Streetview Cars, Uber, or UPS.

Watch those VOCs! Open Source Air Quality Monitor

Ever consider monitoring the air quality of your home? With the cost of sensors coming way down, it’s becoming easier and easier to build devices to monitor pretty much anything and everything. [AirBoxLab] just released open-source designs of an all-in-one indoor air quality monitor, and it looks pretty fantastic.

Capable of monitoring Volatile Organic Compounds (VOCs), basic particulate matter, carbon dioxide, temperature and humidity, it takes care of the basic metrics to measure the air quality of a room.

Exploded CAD View

All of the files you’ll need are shared freely on their GitHub, including their CAD — but what’s really awesome is reading back through their blog on the design and manufacturing process as they took this from an idea to a full fledged open-source device.

Did we mention you can add your own sensors quite easily? Extra ports for both I2C and analog sensors are available, making it a rather attractive expandable home sensor hub.

To keep the costs down on their kits, [AirBoxLab] relied heavily on laser cutting as a form of rapid manufacturing without the need for expensive tooling. The team also used some 3D printed parts. Looking at the finished device, we have to say, we’re impressed. It would look at home next to a Nest or Amazon Echo. Alternatively if you want to mess around with individual sensors and a Raspberry Pi by yourself, you could always make one of these instead.

Air Wick Odor Detect teardown

air_wick_odor_detect_teardown

[Hunter’s] wife came home from her latest extreme couponing session with a handful of free Air Wick Odor Detect air fresheners, and since they had so many of the things sitting around, he was compelled to take one apart to see what makes them tick.

The casing was secured with melted snap tabs which had to be cut, making disassembly a one-way street. Once opened, he found a trio of white label AA cells and an ARNIE COMPACT3 ISS.4 controller board, complete with an epoxy-sealed microcontroller. A similarly branded sensor board was attached to the controller, and he spotted a solenoid with a built-in nozzle for spraying air freshener as well.

The sensor board piqued his curiosity the most, and after some research he’s pretty sure that the Air Wick uses an Applied Sensor VOC air quality module to get the job done. The tiny sensor uses a special substrate containing electrodes, which measure the resistance of the sensing layer while it is heated to upwards of 400° C.  A change in resistance lets the air freshener know that it’s time to handle the odoriferous emanations floating about.

Thanks to [Hunter] for taking the time to tear the Air Wick down and letting us know what’s inside!