PM2.5 is a pollution sensor base with affordable price and high performance. Integrated with PMSA003 and SHT20, makes it possible to measure the ambient quality of air, temperature, and humility all at one device.
Much discussion and research have taken place within academic and government environmental organizations as to how accurate such sensors are and whether they have a place in the enforcing of environmental regulation, or even providing an indication of air quality trends to citizens.
With M5Stack product series, the system makes it much easier to deploy the measurement node all around the city and make it possible to build a complete ecosystem from regulation enforcement to citizen indication.
With regards to PMSA003, it is a digital universal particulate concentration sensor designed by using the principle of laser scattering method. It is capable of continuous acquisition and computing the number of suspended particles in per unit volume which is also the particulate concentration distribution. Then turn it into mass concentration and output through digital GPIO.
- Precise measurement implemented by laser scattering method.
- Digital output, standard UART communication
- 0 error alarm rate
- real-time response
- continuous acquisition
- Minimum particle size resolution: 0.3 µm
- Pattern structure design, 6-sides full dimension cover, high anti jamming capability
- Alternative in-outlet direction, wide application scale. users no need to redesign the air flue.
- Tiny body, 12 mm. good for portable and wearable device
SHT20 is a Humidity and temperature sensor IC.
- Fully calibrated
- Digital output, I2C interface
- Low power consumption
- The excellent long term stability
- DC 5V
- Compatible with M5stack stackable and extension system.
- M5Core pedestal (Pin out SPI/I2C/Power)
- Proto board
- USB Type-c port
- 1x PM2.5 base
- 1x M5Stack Basic
- 1x M5Core pedestal
- 1x Type-c cable
- 2x M3 screw
LEARN AND DOCUMENTS
First off just about all of these m5stack units are great little dev kits with enough fit and finish to use in final projects. The PM sensor is well-integrated into the back making this a really compact. However the temperature sensor is practically worthless. I am assuming the SHT20 is genuine but the design of this puts the sensor way too close to the heat of the microcontroller/backlight/etc. Both units I purchased read about 7-8 degrees C over ambient air (and the humidity is similarly reading about 10% low). I can't help but thinking they would have been better off with their other temp sensor stand as a base rather than trying to integrate the temp sensor so tightly next to the PM sensor. However, this is not the end of the world--they appear to be relatively consistent in their error so you can do some calibration in your software or you can use a separate sensor off the I2C port for your own temperature/humidity. I also added a VOC sensor making it a great full-featured DIY IAQ solution. PM sensor appears to report reasonable/consistent results. Aside from the temp/humidity sensor issues, the only other thing I'd have liked to see is more GPIO broken out somewhere, since the standard m5stack backplate is replaced by the PM sensor you only get the I2C port and the small handful of pins on the bottom for the stand. Great little kit though, if you want a decent looking DIY PM sensor with a screen that you don't have to make your own enclosure for, get it!
PM2.5 Air Quality Kit (PMSA003 + SHT20)
The M5stack with pm2.5 sensor makes the job out of the box. Software support is based on github and the environment visual studio code (not arduino devkit). Information on building such programming environment is too limited. Thus there is no out of the box, easy way to compile and modify the script for example to build a small api.