Coffee Grinder Timer ☕️

The project was started when I bought a used Mazzer Super Jolly and wanted to mod it and control it based on time. I removed the doser from the grinder, added a funnel, had the grinder repainted, and started working on this project.

The project is built in Visual Studio Code.

(click to play video)

Parts list

• Arduino Nano
• ST7735 1.8" TFT (https://www.ebay.co.uk/itm/191786659555)
• Rotary encoder w. click (Something like https://www.elextra.dk/details/H35684/rotary-encoder-18-trin-m-trykknap-funktion)
• Relay(s) (I don't really know much about relays and am still experimenting with this. When I originally started this project I did this drawing for my Mazzer Super Jolly, so perhaps two relays are needed.)
• Possibly some sort of power supply

Pins

Connection between ST7735 and Arduino Nano

• VCC ⟶ 5V
• GND ⟶ GND
• CS ⟶ D10
• RESET ⟶ D8
• A0 / DC ⟶ D9
• SDA ⟶ D11
• SCK ⟶ D13
• LED ⟶ 3V3

Connection between rotary encoder and Arduino Nano

• Rotary envoder pin 1 ⟶ A0

• Rotary envoder pin 2 ⟶ GND

• Rotary envoder pin 3 ⟶ A1

• Button pin 1 ⟶ A2

• Button pin 2 ⟶ GND

Connection between relay and Arduino Nano

These specifications are speculations as I currently don't have a relay hooked up - but it should be fairly simpel:

• GND ⟶ GND
• VCC ⟶ 5V
• IN ⟶ D2

Interface

Everything is controls by either turning (Turn), clicking (Click) or holding (Hold (∞)) / holding+releasing (Hold (2s)+R) the rotary encoder:

General

• Turn to pick one of the following grinding options:

• Manual grinding

  • Hold (∞) to grind

• Single grinding

  • Click to start grinding
    • Click to cancel grinding
  • Hold (2s)+R to enter settings:
    • Turn to change time
    • Click to save settings
    • Hold (2s)+R to exit settings without saving

• Double grinding

  • Click to start grinding
    • Click to cancel grinding
  • Hold (2s)+R to enter settings:
    • Turn to change time
    • Click to save settings
    • Hold (2s)+R to exit settings without saving