Grinder is an iOS 10 app I made to turn on my espresso machine from my phone and grind my coffee. Mostly, I use it to turn on the espresso machine from bed in the morning so I don't have to wait for it to preheat. It also lets me grind coffee from my phone and even specify the amount of coffee I want ground.

Pictured, gaggia classic espresso machine with Arduino microcontroller and relay connected to the espresso machine power switch. The Arduino is of the Wemos variety so it has a wifi chip built in and can connect to the internet.

Pictured, Starbucks barista burr grinder with Arduino microcontroller and relay connected to the power switch. This is an Arduino uno with a Red Bear Labs bluetooth low energy shield so it can connect to my iphone via bluetooth.

How does it work

Tab 1 of the app accesses a mobile friendly webpage that is hosted on an Arduino microcontroller that is connected to the power switch on my espresso machine in my kitchen. Tab 2 connects using Bluetooth to another Arduino that is wired to my coffee grinder. I can specify a weight of ground coffee I would like, and the Arduino will stop the coffee grinder once this weight has been reached. 

Pictured, tab 1 of Grinder app

Tab 2 of Grinder app

Links to Source Code

Grinder on github