By Collin Allen

BrewBot - Sending Coffee Notifications to Slack

September 16, 2017

At work, we have a coffee machine that serves dozens of people in the building, and it’s difficult to know when to come get fresh coffee. You might arrive when it’s empty and be tasked with making more, but the ideal situation is to arrive just as a fresh pot is being brewed.

We also use Slack for team chat and various notifications, so integrating the coffee machine status was a no-brainer. Using a non-invasive/inductive current sensor and Raspberry Pi, the following setup monitors coffee machine energy consumption and waits for a significant rise in current draw, followed by several minutes of sustained usage. Once a time threshold has passed, it does an HTTP POST to a Slack webhook, sleeps for about 15 minutes, then starts monitoring again. This “brewbot” code is available on GitHub, and a parts list can be found below.

Completed kit

Packaged in box

ADC board

Full parts list:

Related reading: Hyper Text Coffee Pot Control Protocol