Grafana is one of the most powerful platforms to manage and visualize data. After installation, select Grafana in the dashboard list and click
The browser will open and show us the page http://localhost:3001. You can also connect to this page from any device connected to the same network as OpenPlotter using the address http://openplotter.local:3001.
The initial username and password are both set to admin. On the next page we will be asked to change and verify a new password.
There are many ways to manage and display data in OpenPlotter using Grafana, but in this short tutorial we will focus on how to display data from the Signal K server in real time. We want to catch the delta messages that the server sends over the websocket connection, so we will use the WebSocket API plugin that is pre-installed in OpenPlotter.
Add data source. Select WebSocket API at the end of the list and write ws://localhost:3000/signalk/v1/stream?subscribe=all in
After saving, Grafana will be ready to receive all delta messages for all existing Signal K keys and values. Now we need to filter a Signal K key to be displayed on a dashboard, for this example we will use environment.outside.temperature.
Add a new panel. In the
Query tab, select WebSocket API as the
Data Source and add 3
Fields by filling in the
Alias fields using the data from the image below:
Finally go to
Transform tab and add the
Filter data by values transformation using the settings shown in the image below:
Signal K uses the Kelvin unit for temperature, so if we want to convert the data to Celsius, we can add another transformation
Add field from calculation using the settings in the image above.
Once you are happy with your panel click
Save and continue building your perfect dashboard by adding more panels.