Anyone have experience using a laser based air quality sensor? Do they actually work and provide useful information?
Just ordered a Plantower PMS5003 for $32, will try to hook it up to a Pi to experiment with once it gets here from china. It’s at least much cheaper than consumer units like Dylos or Speck which are $200-$300.
I don’t have any direct experience but a UT Dallas speaker for a group that I organize discussed a project testing them, machine learning for interesting information from the resulting dataset, and an upcoming local deployment of them at various locations around DFW.
http://www.utdallas.edu/news/2016/3/7-31941_Project-Aims-to-Make-Breathing-Easier-by-Mapping-A_story-wide.html?WT.mc_id=NewsHomePage
https://davidlary.info/
http://www.dallas-sensor.com/march-sensor-forum-intelligence-at-the-edge-the-intel-quark-line/
Ended up ordering 2 to compare, got in the SDS018
It appears to work, it measured the soot from blowing out a candle by pegging the PM2.5 meter at 999 ug/m^3, over 1 minute:
Now the question is how to package it to make it useful at DMS, just sending data to a cloud service would probably be the easiest thing to do, only requiring a powersupply to be plugged in.
Woodshop air monitor!
(insert evil grin here…)
This service looks promising, http://sensorcloud.com/
Anyone know of other similar IOT sensor collecting services? SensorCloud has a free tier, but limited to 25,000 transactions per month, will have to buffer the data for an hour then upload data sampled at 15 or 30 seconds worth.
Another is ATT M2X at https://m2x.att.com/ but it has the same model as all that I know of ie free for small volume, $ for large volume.
Thanks for the tip, M2X looks awesome and very easy to use, I haven’t written the code to push data yet but it can be made public like: https://m2x.att.com/catalog/4f62aee459c385ac304f53bc16a26bad
They even have a Go library, but using the rest api looks just as easy
Trying to test out the Plantower PMS 5003 with the same smoke test as above, but as soon as a candle is lit anywhere near it the sensor locks up, not sure if its just the PMS5003 or in combination the cheap serial to usb converter it’s going through, dmesg shows:
cp210x ttyUSB0: usb_serial_generic_read_bulk_callback - urb stopped: -32
Going by the quality of the datasheet, I prefer the SDS018 by a lot anyway, was hoping to be able to run two different sensors in parallel.
I’m throwing in an AM2302 to read temp/humidity, but the control scheme on that chip is a one off single pin requiring precise timing to read, there is an adafruit python library that uses a c driver, but having the program shell out to python is too shameful (not to mention the whole retry lots of time because kernel may interupt while reading reliability issues)
Since I would like to run all the sensors off a powered usb hub anyway, I can just use an arduino just to interface with the temp sensor, and then communicate over a usb to serial converter to that arduino
So I will have microcontrollers to talk to microcontrollers to talk to microcontrollers
Got around to getting all the sensors working and mounted on something. Some other tips, don’t buy a USB 3 hub for a raspberry pi (very likely not supported), and making symlinks for the /dev/ttyUSB# devices makes them a lot easier to work with. Now just need to throw together some code to post these values to a rest api every couple minutes or so
Got a cron job setup to execute the go program to post data every 4 minutes to here (to stay below the 100k values / month free tier with 7 values being tracked here). The source is on github, it is very basic
Now just need to hang this piece of wall art inconspicuously in woodshop and see how long it survives (the outlets on ceiling powering the hanging box air filters should work great for this)
In theory this is a png that is generated on demand with latest data(currently running on my desk and not at DMS) as long as discourse will keep the actual link and not cache the image
System is mounted on the wall in woodshop and running, I must be incorrectly reading the PMS sensor but the SDS and temp are working.
The costs for the parts on the one in woodshop would be $190 if you had to buy everything, but you could most likely get away with running one air sensor and the temp sensor directly off the pi instead of through a powered hub, then your costs would be something like:
Raspberry Pi 3 $35.00
SDS 021 $22.56
Arduino Uno $10.00
DHT22 Temp Sensor $9.99
Pi Power supply $7.50
Pi 3 case 2/ heatsinks $6.95
CP2102 USB UART $5.47
~$100
Insteresting to compare against current statewide PM2.5 readings or hourly downtown reading, if the sensors are accurate then at least right now the air in the woodshop is cleaner than the outside air.
Just contributing another service I have played with:
and my test channel
