Saturday 2 p.m.–2:20 p.m.

Coffeebot 3000 - An IoT story with a RaspberryPI, Redis, LEDs, and Mario

James Alexander

Audience level:


This is a story about the creation, maintenance and on-going features built onto an IoT device to measure the amount of coffee in a coffee pot.


Topics and technology covered:

  • Managing RaspberryPI Wifi connections
  • Reading binary data from a USB scale
  • Drawing Bitmap art to an LED Display connected via GPIO to the RaspberryPI
  • Using Redis PubSub to control the queue of graphics and animations displayed on the LED panel.

Features of Coffeebot 3000:

  • Measures the remaining coffee in a pot, and displays the amounts on an LED panel
  • Responds when a user lifts the pot, and updates the display after replacing the pot
  • If the pot has less than 1 mug, or has been on the scale for 2 hours or more, a random animation will be shown. Possible animations: Mario running across the display, a group of Red LEDs oscillating back and forth, or Conway's Game Of Life in various initial configurations with random colors for each pixel.