Variable-Speed Slow Bean Feeder for DF64 / DF64V Coffee Grinders

This slow bean feeder provides consistent, controlled feeding of coffee beans into DF64 or DF64V grinders.

Features:

• Variable Speed via potentiometer
• USB Powered (5V) with optional LiPo battery support
• Direction Reverse with push button to clear jamming

Required Components:

• 28BYJ-48 Stepper Motor (5V)
• Stepper Motor Driver Board (e.g., ULN2003)
• Arduino Nano (or compatible board)
• M6 Toggle Switch (to toggle power)
• Potentiometer with knob (1K recommended)
• ~10mm Momentary Micro Push Button (to reverse direction)
• 3 M3x5 Machine Screws (to fasten base to enclosure)

Optional:

• Small LiPo Battery
• TP4056 (or similar) Charger + Protection Module 

Assembly:

1. Mount the stepper motor from the bottom using two M3 machine screws and nuts.
2. Mount the toggle switch, push button and potentiometer and wire them into the arduino.
3. Attach the cabling between stepper motor, driver board and arduino.
4. (optional) Connect LiPo to TP4065 and TP4065 to arduino. 
5. Flash the arduino and test the setup. (Arduino sketch is provided under other files).
6. Push all components into enclosure and attach base with three M3 screws.
7. Push bean wheel onto stepper motor shaft.
8. Remove the bellows from the grinder and place the Slow Feeder on top. (You can replace the bellows after the grinding is finished).

Wiring:

Arduino Connections:

Power and Ground Connections: