The first step of my sensor network is completed. A BMP280 barometer sensor, a Raspberry Pi with an MQTT broker, a round robin database, an apache webserver and some Python and shell magic.
A Python scripts reads the pressure and the temperatur from the sensor and sends the values to an MQTT broker. This happens every minute. A shell script running as a sort of a deamon reads these values and sends them to the appropriate RRD. Every five minutes another shell script reads the database and creates graphs for last hour, last week, last month, and last year. The graphs are copied to the local web server.
Here is the one-week-graph for the air pressure:
And the corresponding graph for the temperature:
The scripts are on github.
