Building a Mood Barometer: The IoT Workshop at Swiss Re

In early 2020, I hosted a hands-on IoT workshop at Swiss Re. The challenge? Build a mood barometer — a physical dial that reflects the emotional “weather” of a space.

Each team flashed an ESP32, wrote Arduino code to read mood values over HTTP or MQTT, and moved a dial to match. No soldering — just ESP32 boards, stepper motors, and a magnet sensor wired up to detect calibration points. A few hundred francs in parts. Build it. Ship it. Make it move.

I prepped three micro-projects to help them get there:

• mood-barometer:
  ESP32-based analog mood dial powered by a stepper motor and magnet sensor. It listens for MQTT messages and moves the needle to happy, neutral, or sad. Includes the GIMP dial art and Fusion 360 housing.

• mood-infrared-controlled:
  For teams that didn’t want to mess with networking. Used any IR remote to manually set the mood. Just fun to play with.

• mood-mqtt-client-nodejs:
  Node.js MQTT publisher — a CLI tool to simulate inputs or act as a bridge between UI and device.

A colleague stepped up and helped design a custom PCB, so teams weren’t fumbling with jumper wires all day. That took things to another level. Everyone had something solid to build with — and take home.

Some used a local MQTT bridge, others connected to Azure IoT Hub with device provisioning and telemetry reporting. A few hundred francs in hardware, a shared repo, and some printed cheat sheets — that’s all it took.

It turned out to be one of the most satisfying workshops I’ve ever run.