This server hosts an MQTT broker for "internet of things" applications within the Department of Chemistry at the University of Wisconsin-Madison.

This server is maintained by Blaise Thompson and the Chemistry Instrument Shop. Please contact them with any questions or concerns. This service is "best-effort" and uptime is not guaranteed. Please design your instrumentation software to be robust in the event of an outage. Luckily MQTT's core design makes this relatively easy!


This server runs mosquitto, an MQTT broker. Briefly, MQTT is a lightweight publish-subscribe protocol that allows many devices to communicate. The broker provides structured topics, e.g. "sensor42/temperature" and "instrument9/opa2/wavelength". Clients can publish topic updates. Other clients can subscribe to be notified each time a topic is updated. Refer to for more information.

Anyone on the campus network can subscribe to the topics served here. There are lots of great MQTT clients you can use. We recommend:

To see all topic updates on your command line:

mosquitto_sub -h -t "#" --verbose

You'll need a password to publish to this broker. Talk to Blaise Thompson to get a password.


MQTT doesn't have any data recording capabilities built-in. It's easy to set up your own little recording application, or you can build on top of our infrastructure by using the Homie Convention.

We have built tooling around the Homie convention. Any data published to this server obeying the homie convention will be automatically recorded into our time series database, Graphite. We also have a Grafana appliance set up to visualize data from Graphite.


Here are some dashboards.

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