Monitor The Pollution On Your Commute

June 22, 2019 by Jenny List 17 Comments

Commuting through the urban sprawl of a 21st century city brings exposure to significant quantities of pollution. For a Medway Makers member that meant the Isle of Dogs, London, and a drive through the Blackwall Tunnel under the Thames. When you can taste the pollution in the air it’s evident that this isn’t the best environment to be in, but just how bad is it? Time to put together an environmental monitoring and recording rig.

Into the build went an ESP32 module, an SPS30 particulate sensor, an MH-Z19 CO₂ sensor, an HTU21D temperature and humidity sensor, and a uBlox NEO 6M GPS module. The eventual plan is to add an SD card for data logging, but in the absence of that it connects to a Raspberry Pi running Grafana over InfluxDB for data analysis. The result provides a surprising insight into the environmental quality of not just a commute but of indoor life. We’re sorry to say that they don’t seem to have posted any of the code involved onto the Medway Makers writeup, though we hope that’s an oversight they’ll rectify by the time this has gone live.

This isn’t the first environmental monitor to grace these pages, indeed we’ve had quite a few as Hackaday Prize entries.

Building An Army Of ESP32 Air Quality Sensors

April 5, 2019 by Tom Nardi 20 Comments

The ESP8266 and its heavyweight sibling the ESP32 are fantastic boards to develop with as they allow you to quickly and easily get a project online. Just tack a few sensors and some LEDs on them, and you’re well on the way to producing your own “Internet of Things”. The real challenge is utilizing the incredible capabilities these boards offer us to do something meaningful.

Judging by what he’s got so far, we think [Samuel Klit] is well on his way. He’s using the ESP32 and some off-the-shelf modular components to create an Internet-connected air quality monitoring station. But he’s not just building one or two of them, he’s building enough so they can be distributed and collect data over a wide area. Who knows, perhaps you’ll be building one next.

[Samuel] is using the CCS811 sensor which can pick up potentially harmful Volatile Organic Compounds (VOCs) and determine carbon dioxide concentrations, as well as a BMP280 sensor to read ambient temperature and atmospheric pressure. There’s also an SD card reader for local data storage, a 1602 LCD display that provides a basic user interface, and the electronics required to support the 18650 Li-Ion batteries which power the unit for up to 12 hours on a charge. Everything’s held in a professional looking enclosure that we’ll be sure to add to our next AliExpress order.

Collecting data is one thing, but what do you do with it once you’ve got it? To that end, each node runs a web interface that not only allows you to view current hardware status and download the locally stored data, but also provides an easy to understand visual representation of the environmental conditions. To get around the limited storage space for web assets on the chip, [Samuel] is calling out to Chart.js to inject some slick graphics into the web interface on-demand. The web interface is a particularly nice touch, and an excellent use of the power and capabilities offered by the ESP32.

We’ve previously seen air quality sensors added to Taxi cabs in Peru, the homes surrounding Barcelona’s Plaza del Sol, and of course [Radu Motisan] has done incredible work towards the goal of creating city-wide environmental monitoring networks. With increasingly capable technologies, it looks like citizens are studying the world around them in greater numbers than ever before.

Continue reading “Building An Army Of ESP32 Air Quality Sensors” →

Forbes Says The Raspberry Pi Is Big Business

March 18, 2019 by Tom Nardi 45 Comments

Not that it’s something the average Hackaday reader is unaware of, but the Raspberry Pi is a rather popular device. While we don’t have hard numbers to back it up (extra credit for anyone who wishes to crunch the numbers), it certainly seems a day doesn’t go by that there isn’t a Raspberry Pi story on the front page. But given that a small, cheap, relatively powerful, Linux computer was something the hacking community had dreamed of for years, it’s hardly surprising.

But how popular is the Raspberry Pi among people who don’t necessarily spend their free time reading weird black-background websites? Well, according to a recent article in Forbes, the Pi has been spotted putting in an honest days work all over the world. From factories to garbage trucks, everyone’s favorite Linux computer has come a long a way from its humble beginnings. How does it feel knowing a $35 computer has a longer resume than you do?

Unfortunately, the Forbes article doesn’t have the sort of deep technical details we’re used to around these parts. The fact that the article opens by describing the Raspberry Pi as a “stripped-down circuit board covered with metal pins and squares” should tell you all you need to know about the overlap between Forbes and Hackaday readers, but we think author [Parmy Olson] still tells an story interesting regardless.

So where has the Pi been seen punching a clock? At Sony, for a start. The consumer electronics giant has been installing Pis in several of their factories to monitor various pieces of equipment. They record everything from temperature to vibration and send that to a centralized server using an in-house developed protocol. Some of the Pis are even equipped with cameras which feed into computer vision systems to keep an eye out for anything unusual.

[Parmy] also describes how the Raspberry Pi is being used in Africa to monitor the level of trash inside of garbage bins and automatically dispatch a truck to come pick it up for collection. In Europe, they’re being used to monitor the health of fueling stations for hydrogen powered vehicles. All over the world, businesses are realizing they can build their own monitoring systems for as little as 1/10th the cost of turn-key systems; with managers occasionally paying for the diminutive Linux computers out of their own pocket.

The impact the Pi has had on the hardware world is difficult to overstate. It’s redefined the status quo for single board computers, and with the platform continuing to evolve, there’s no sign its incredible journey is slowing down anytime soon.

[Thanks to Itay for the tip.]

A Network Attached Radiation Monitor

February 13, 2019 by Tom Nardi 25 Comments

It started as a joke, as sometimes these things do. [Marek Więcek] thought building a personal radiation detector would not only give him something to work on, but it would be like having a gadget out of the Fallout games. He would check the data from time to time and have a bit of a laugh. But then things got real. When he started seeing rumors on social media that a nearby nuclear reactor had suffered some kind of radiation leak, his “joke” radiation detector suddenly became serious business.

With the realization that having his own source of detailed environmental data might not be such a bad idea after all, [Marek] has developed a more refined version of his original detector (Google Translate). This small device includes a Geiger counter as well as sensors for more mundane data points such as temperature and barometric pressure. Since it’s intended to be a stationary monitoring device, he even designed it to be directly plugged into an Ethernet network so that it can be polled over TCP/IP.

[Marek] based the design around a Soviet-era STS-5 Geiger tube, and outfitted his board with the high voltage electronics to provide it with the required 400 volts. Temperature, barometric pressure, and humidity are read with the popular Bosch BME280 sensor. If there’s no Ethernet network available, data from the sensors can be stored on either the built-in SPI flash chip or a standard USB flash drive.

The monitor is powered by a PIC32MX270F256B microcontroller with an Ethernet interface provided by the ENC28J60 chip. In practice, [Marek] has a central Raspberry Pi that’s polling the monitors over the network and collecting their data and putting it into a web-based dashboard. He’s happy with this setup, but mentions he has plans to add an LCD display to the board so the values can be read directly off of the device. He also says that a future version might add WiFi for easier deployment in remote areas.

Over the years we’ve seen a fair number of radiation monitors, from solar-powered WiFi-connected units to the incredible work [Radu Motisan] has done building his global network of radiation detectors. It seems hackers would rather not take somebody else’s word for it when it comes to the dangers of radiation.

The Short And Tragic Story Of Life On The Moon

January 23, 2019 by Tom Nardi 66 Comments

The Moon is a desolate rock, completely incapable of harboring life as we know it. Despite being our closest celestial neighbor, conditions on the surface couldn’t be more different from the warm and wet world we call home. Variations in surface temperature are so extreme, from a blistering 106 C (223 F) during the lunar day to a frigid -183 C (-297 F) at night, that even robotic probes struggle to survive. The Moon’s atmosphere, if one is willing to call the wispy collection of oddball gasses including argon, helium, and neon at nearly negligible concentrations an atmosphere, does nothing to protect the lunar surface from being bombarded with cosmic radiation.

Yet for a brief time, very recently, life flourished on the Moon. Of course, it did have a little help. China’s Chang’e 4 lander, which made a historic touchdown in the Von Kármán crater on January 3rd, brought with it an experiment designed to test if plants could actually grow on the lunar surface. The device, known as the Lunar Micro Ecosystem (LME), contained air, soil, water, and a collection of seeds. When it received the appropriate signal, LME watered the seeds and carefully monitored their response. Not long after, Chinese media proudly announced that the cotton seeds within the LME had sprouted and were doing well.

Unfortunately, the success was exceptionally short-lived. Just a few days after announcing the success of the LME experiment, it was revealed that all the plants which sprouted had died. The timeline here is a bit hazy. It was not even immediately clear if the abrupt end of the LME experiment was intentional, or due to some hardware failure.

So what exactly do we know about Chang’e 4’s Lunar Micro Ecosystem, and the lifeforms it held? Why did the plants die? But perhaps most importantly, what does all this have to do with potential future human missions to that inhospitable rock floating just a few hundred thousand kilometers away from us?

Continue reading “The Short And Tragic Story Of Life On The Moon” →

The Electric Imp Sniffs Out California Wildfires

November 20, 2018 by Tom Nardi 13 Comments

The wildfires in California are now officially the largest the state has ever seen. Over 50,000 people have been displaced from their homes, hundreds are missing, and the cost in property damage will surely be measured in the billions of dollars when all is said and done. With a disaster of this scale just the immediate effects are difficult to conceptualize, to say nothing of the collateral damage.

While not suggesting their situation is comparable to those who’ve lost their homes or families, Electric Imp CEO [Hugo Fiennes] has recently made a post on their blog calling attention to the air quality issues they’re seeing at their offices in Los Altos. To quantify the problem so that employees with respiratory issues would know the conditions before they came into work, they quickly hacked together a method for displaying particulate counts in their Slack server.

The key to the system is one of the laser particle sensors that we’re starting to see more of thanks to a fairly recent price drop on the technology. A small fan pulls air to be tested into the device, where a very sensitive optical sensor detects the light reflected by particles as they pass through the laser beam. The device reports not only how many particles are passing through it, but how large they are. The version of the sensor [Hugo] links to in his blog post includes an adapter board to make it easier to connect to your favorite microcontroller, but we’ve previously seen DIY builds which accomplish the same goal.

[Hugo] then goes on to provide firmware for the Electric Imp board that reads the current particulate counts from the sensor and creates a simple web page that can be viewed from anywhere in the world to see real-time conditions at the office. From there, this data can be plugged into a Slack webhook which will provide an instantaneous air quality reading anytime a user types “air” into the channel.

We’ve covered a number of air quality sensors over the years, and it doesn’t look like they’re going to become any less prevalent as time goes on. If anything, we’re seeing a trend towards networks of distributed pollution sensors so that citizens can collect their own data on their air they’re breathing.

[Thanks to DillonMCU for the tip.]

Hacking The ZH03B Laser Particle Sensor

October 9, 2018 by Tom Nardi 23 Comments

Laser particle detectors are a high-tech way for quantifying whats floating around in the air. With a fan, a laser, and a sensitive photodetector, they can measure smoke and other particulates in real-time. Surprisingly, they are also fairly cheap, going for less than $20 USD on some import sites. They just need a bit of encouragement to do our bidding.

[Dave Thompson] picked up a ZH03B recently and wanted to get it working with his favorite sensor platform, Mycodo. With a sprinkling of hardware and software, he was able to get these cheap laser particle sensors working on his Raspberry Pi, and his work was ultimately incorporated upstream into Mycodo. Truly living the open source dream.

The ZH03B has PWM and UART output modes, but [Dave] focused his attention on UART. With the addition of a CP2102 USB-UART adapter, he was able to connect it to his Pi and Mac, but still needed to figure out what it was saying. He eventually came up with some Python code that lets you use the sensor both as part of a larger network or service like Mycodo and as a stand-alone device.

His basic Python script (currently only tested on Linux and OS X), loops continuously and gives a running output of the PM1, PM2.5, and PM10 measurements. These correspond to particles with a diameter of 1, 2.5, and 10 micrometers respectively. If you want to plug the sensor into another service, the Python library is a bit more mature and lets you do things like turn off the ZH03B’s fan to save power.

These sensors are getting cheap enough that you can build distributed networks of them, a big breakthrough for crowd-sourced environmental monitoring; especially with hackers writing open source code to support them.