The Purple Grinder
Creator and Developer
The Purple Grinder is a smart coffee grinder. It was created as a low-cost and high-performance alternative to commercial grinders. TPG uses a Hario Slim grinder and can be controlled by an app.
THE PURPLE GRINDER
My goal with TPG was to create a very simple and straightforward device: it has just one activation button. After activated, the grinder runs by the configurated time - that can be changed using an app - that can vary from 1 to 5 minutes.
Even the building is very simple: the only modification that has to be made in the Hario Mill is the installation of a spring pin in the central axis.
Connecting and changing the TPG parameters with the app is also very simple: just points the smartphone camera to the special QR-Code in the device. After that, the app just connects to the 802.11 network of the device and then is possible to configure the TPG.
HOW I BUILT IT
This project took 60 hours of work. All the design, hardware integration, and software development were made by me.
I used an ESP8266 microcontroller. The code was made in C++11. I configurated the ESP8266 in AP mode and the implemented a REST web service API in it.
The Android app was made with Kotlin.