This is a simple example of how to use asyncio to simulate async reading from sensors and write it to a database (either mongo or sqlite).

Mosquitto is needed for mqtt messaging.

SQLite3 is needed for managing the DB.

(Optional) MongoDB is needed for managing the DB.

Virtualenv provided:

• python 3.7
• asyncio 3.4.3
• numpy 1.16.2
• paho-mqtt 1.4.0
• pymongo 3.7.2

There are 3 main files:

• initsqlite.py initializes the database and defines the schema to be used.
• sensors.py uses asyncio to simulate data from different sensors and publishes those readings through mqtt.
• subscriber.py subscribes to the different topics and writes everything on a database.

Always run initsqlite.py first to create or reset the database. Then, run subscriber.py to start listening and don't lose any message and finally run sensors.pyto start publishing the data.

First install all the requirements:

apt-get install mosquitto
apt-get install sqlite3 mongodb-org

$ git clone https://github.com/HernanG234/sensors_async_sim.git
$ cd sensors_async_sim
$ git checkout sample
$ source venv/bin/activate
# You should see (venv) at the beggining of your terminal
(venv) $ python initsqlite.py
(venv) $ python subscriber.py

# Open a new terminal
$ source venv/bin/activate
(venv) $ python sensors.py

If you are not using the virtualenv provided, install the requirements using pip and then run the steps above:

$ pip install -r requirements.txt

Check that everything worked from SQLite:

$ sqlite3 iot-sqlite.db
sqlite> .tables
frequency     pressure      temperature
sqlite> select * from pressure;
# You should see the readings here!

Install all the requirements:

• Download Mosquitto QuickInstall for Windows: http://www.steves-internet-guide.com/install-mosquitto-broker/
• Download Sqlite for Windows: https://sqlite.org/2019/sqlite-tools-win32-x86-3280000.zip
• pip install requirements.txt

Execute each in a separate PowerShell:

.\mosquitto

python initsqlite.py
python subscriber.py
python sensors.py

Once it is finished, you can check that it worked from sqlite:

sqlite3.exe

Inside Sqlite:

.open iot-sqlite.db
.tables
select * from pressure;

• MQTT messaging
• Implement writing to mongo.
• Implement writing to sqlite.
• Add "signals" to sensors (noise, step, ramp, etc.) to plot ant query sth nicer
• Accept arg to select mongo or sqlite.
• Plot