python-friskby

Overview

The friskby module is a Python module for reading from external sensors (currently, only the SDS011 sensor is supported), store measurements to a temporary database and post the measurements to a webserver.

In the future we will add other sensors for temperature, relative humidity, barometric pressure, noise level detection, luminosity, etc, and will post data for such sensors to a webserver.

Install

To install, you may use pip:

sudo pip install friskby

Or from source:

git clone https://github.com/FriskByBergen/python-friskby.git
cd python-friskby
sudo pip install .

Description of functionality

The module consists of three primary features:

1. sampling
2. submitting
3. updating

FriskbySampler

The FriskbySampler is a module that connects to the sensor and samples information about the weather, air, climate or surrounding environment, and stores the data to the FriskbyDao. The FriskbyDao is a data access object that currently persists measured data to an SQLITE file using the sqlite3 Python module.

The underlying database scheme is simple:

CREATE TABLE samples (
    `id` INTEGER PRIMARY KEY,
    `value` FLOAT NOT NULL,
    `sensor` TEXT NOT NULL,
    `timestamp` TEXT NOT NULL,
    `uploaded` BOOL DEFAULT 0
    );

The sensor describes contains the sensor ID and describes what type of measurement has been done. The value is its value (in an assumed known (SI) unit). The uploaded flag signifies whether the measurement has been uploaded, which is dealt with by the

FriskbySubmitter

The FriskbySubmitter reads non-uploaded measurements from the FriskbyDao and submits these measurements to the prescribed webserver. The URL and API key for the webserver is defined in a config file provided by the caller. The submitter uses the requests module in Python (it is recommended that one has requests>=2.13.0, which is the latest one).

FriskbyManager

The job of the FriskbyManager is to read the aforementioned config file, contact the webserver and ask for today's news. They are rare, but may contain reconfiguration of API keys, URL's and occasionally requests that the client updates itself.

RPiParticle

These features mentioned above are used from the RPiParticle project, but can also be used by other daemons or cron jobs. The RPiParticle launches one systemd job for each of the above.