Purple Air PAII sensor data collection

PurpleAir: Real-time Air Quality Monitoring make a number of devices for measuring airborne pollution. When registered the device data can be viewed on the purple air map. There are also APIs for downloading historic sensor data from the cloud.

The device has its own REST API for direct polling - all you need to know is the hostname/ip-address of your sensor(s) and you can point a browser at it. The paii_poll.py script is intended to run continuously, polling the device at regular intervals and storing the data in a (postgresql+timescaledb) database.

Pull requests are welcome.

INSTALLATION

As a prerequisite to run the code you should have:

• a working postgres server
• with a database named "timeseries" (unless you override the name in options)
• a role/user with CREATE TABLE and write access to the "timeseries"
• network setup to access allow the user to access it.
• installation of timescaledb. Note it probably will work without this at a small scale, you would need to supply the --no-timescaledb option.

I have only tested this on fedora/centos. Get the code:

git clone https://github.com/PaulSorenson/purpleair_sensor.git
cd purpleair_sensor

Run directly from source:

PYTHONPATH=. python3.8 scripts/paii_poll.py

Install:

python3.8 setup.py install --user
# or
sudo python3.8 setup.py install

Although scripts/purple_air.ini is not essential it will make running the paii_poll.py script more convenient. To do that make a copy of scripts/purple_air.ini.template alongside paii_poll.py and adjust the entries as necessary.

To manage passwords to your postgres server, there are a few choices:

• If you have installed python keyring and a working back end (eg gnome) then keyring set <user> postgres should stash your postgres password away safely and paii_poll.py will try to retrieve it from there.
• Can add it to the command line - it will be in your bash history so be careful.
• add it to purple_air.ini. At least you can set the permissions so no one else can read it.
• you can be prompted for it.