We love getting our weather in a flurry of different methods, but have you tried building your own sensor suite to harvest the data for you? [Giovanni ‘CyB3rn0id’ Bernardo] needed to monitor isolated locations outside the reach of WiFi. His ray of hope is an ESP32 controller coupled with a LoRa module to beam data to a remote station that can access the cloud.
In addition to radios, he poured a deluge of sensors into the base station to read the temperature, barometric pressure, humidity, and fine dust. Why monitor dust as part of weather data collection? Particulate matter has a huge effect on air quality, something of great interest during a respiratory pandemic. For those readers near wildfires, quantifying your air quality (both indoors and out) is certainly of interest. [Giovanni] is using an SDS011 air quality sensor and has a long writeup just on this part. It uses a fan to move air past a laser-based sensing mechanism.
At the base station, live readings are shown on an OLED screen, but you can also connect to the ESP32 through your phone like a hotspot. If you keep a memory card installed, it will cache the readings in a perpetually-updated CSV file. In regular operation, the LoRa module overcasts the telemetry to its sister unit that acts as a Wifi/LoRa bridge so anyone can view gauges and graphs in real-time on ThingSpeak.
We want to shower [CyB3rn0id] with praise for seeing the
cirrus serious impact of harmful dust and making something that can alert people. We don’t want to rain on anyone’s parade, but sometimes it is better to stay inside.
When measuring air quality, particulate matter is an important metric to watch. The PM2.5 rating refers to particulate matter that has a diameter of less than 2.5 micrometers. While it’s often measured by authorities on a city-wide basis, [rabbitcreek] wanted a way to track down point sources indoors.
The tool [rabbitcreek] built is in a similar form factor to a typical infrared workshop thermometer. Inside, it packs a Honeywell HPMA115S0-TIR laser particle sensor, hooked up to an ESP32 which runs the show. The sensor chosen makes things easy, with the device already set up with a blower and inlet and outlet ports for taking accurate readings.. Results are displayed on an SSD1306 OLED screen. It’s all wrapped up in a 3D printed case with a trigger grip, and a dog nose on the front which hints at the devices true purpose.
In testing, the device proves capable of detecting point sources of atmospheric particulates like flowers and a toaster. It’s something we’re sure would prove handy to those working in HVAC and environmental assessment industries. We’ve seen other rigs for monitoring particulates before, too. Video after the break.
Continue reading “Particle Sniffer For Pollution Point Sources”
Air quality is one of those problems that is rather invisible and hard to grasp until it gets bad enough to be undeniable. By then, it may be too late to do much about it. But if more people were interested in the problem enough to monitor the air around them, there would be more innovators bringing more ideas to the table. And more attention to a problem usually means more accountability and eventual action.
This solar-powered particulate analyzer made by [rabbitcreek] is a friendly way to take the problem out of the stratosphere of ‘someday’ and bring it down to the average person’s backyard. Its modular nature makes it fairly simple to build, and the conch shell enclosure gives it a natural look. That shell also cleverly hides the electronics, while at the same time allowing air and particulates to reach the sensor. If you don’t like the shell enclosure, we think the right type of bird feeder could protect the electronics while allowing airflow.
[rabbitcreek] attached a sizeable solar panel to the shell on a GoPro mount so it can be adjusted to face the sun. The panel charges a Li-Po battery that gets boosted to 5V. Every two hours, a low-power breakout circuit wakes up the Feather ESP32 and takes a reading from the particulate sensor. [rabbitcreek] can easily see the data on his phone thanks to the Blynk app he created.
Why limit this to your yard? Bare ESP32s are cheap enough that it’s feasible to build a whole network of air quality sensors.