How to add a string datasource to a graph?

I’m using Grafana with influxdb to analyze my smart home data. I have some data that contains strings such as “on” or “off” for example. THey are not all boolean, some data chanels include 3 to five different states.
Anyway I’m total noob with grafana and didn’t managed to make string data show up in my graph. I would really appreciate if someone could give me a hint how to do this.