Dummy Sensor Project

Setup a dummy sensor that generates dummy water data which can be pushed to either the screen, a file, or MQTT.

Getting Started

Prerequisites

You will need Docker Compose and Docker installed.

Installing

Use docker-compose to build the images:

docker-compose build

Sensor configuration

The sensor readings are configured in the wq-config.yaml file which is built into the container. If you want to add/remove sensors or changes sensor parameters, you need to edit this file and rebuild the image.

Start the sensor and MQTT and push readings to MQTT

Use docker-compose to start up the MQTT server and start the dummy sensor. The dummy sensor will push data to MQTT in JSON format. The dummy-server service in the doocker-compose.yaml contains configuration parameters that you might want to change.

• interval This is the time in seconds between readings. Currently set to 0.5 = 2 readings per second.
• count This is the maximum number of readings before stopping. Currently set to -1 for infinite readings
• mqtt_topic This is the MQTT topic that the sensor readings will be published to. Currently set to topic/dummy-sensor

docker-compose up -d

Use a mosquitto client (eg. Eclipse Mosquitto) to check that the duumy sensor is ending readings.

mosquitto_sub -p 1883 -t topic/dummy-sensor

And you can stop it by:

docker-compose down

Start the sensor directly

Alternatively, you can run the sensor directly from your Python virtual environment:

pip install -r requirements.txt

# Output readings to screen
python dummy-sensor.py -c wq-config.yaml --interval 0.1 --count 30

# Output readings to file
python dummy-sensor.py -c wq-config.yaml --interval 0.1 --count 30 -o wq-data.txt

# Output readings to a locally available MQTT server
python dummy-sensor.py -c wq-config.yaml --interval 0.1 --count 30 --mqtt-topic topic/dummy-sensor --mqtt-hostname localhost --mqtt-port 1833

Backfill data

If you want to backfill with historical data, use the backfill_date parameter:

python dummy-sensor.py -c wq-config.yaml --interval 600 --backfill_from 2020-04-03 --mqtt_topic topic/dummy-sensor