What is it?

The current used by different appliances can tell you a lot about what they are doing. With IoT it becomes even more useful to track the current and act on it. This is an Arduino UNO shield (used primarily with Yun) that was designed to track two channels of current and provide a status LED to go with it.

Why did you make it?

In our office people were always getting up to see if there was a fresh pot of coffee made. With 20 people sharing a standard pot, this became harder to time. So I built a device that would track the current used by the coffee maker and determine where in the brew cycle it was at any given moment. First the current was logged, then the Arduino was able to detect different current usage and determine when the cycle had completed. After that it would send a message to our internal chat platform. Now you only needed to get up when there was definitely fresh coffee!

What makes it special?

We called the "robot" CoffeeBot and it became a cool symbol of culture in the workplace. I'm honoured that I could build something that so many people have gotten value from.

What is needed?

There are no additional components included in the sale. The minimum elements needed to get a working device are:

• male headers (note that if you want to use something like a Yun with an ethernet port, you'll want longer ones)
• 2x 3.5mm cable to board connectors
• 2x electrolytic capacitors
• 3x 5mm status LEDs with relevant resistors

The board has expansion ports to connect an Adafruit OLED screen as well as a load cell to track actual coffee usage. Have fun!