Hardware

General Overview

There are two main parts in our design - cup dispenser and turntable with cup holes. On the turntable, it has five cup holes with 4'' diameter and one section for personal mug. The cup dispenser holds the reserved cups. We use Handy Board to control the turntable and the cup dispenser.

The top view of the turntable

 

 

 

 

 

 

 

 

 

 

 

Electrical

Basically, we use three photoreflectances to

  • make sure that the cup hole is exactly under the cup dispenser.
  • sense whether or not there is a cup in the cup hole.
  • avoid pouring coffee over the mug section

This is how the photoreflectance is connected. The output is connected to thr I/O ports in Handy Board.

Mechanical

In general, there are two mechanical sections - table section and dispenser section.

1) Table

  • DC motor turns the cup table by a pulley around a wheel connected to the bottom of the table
  • Photoreflectance sensor reacts to appropriately-placed black electrical tape strips on a white plastic tube to determine hole-under-dispenser alignment. White tube also acts as a spacer for desired table height.


2) Cup Dispenser

  • Cup replacement system consists of a "Dixie Cup"-type dispenser, a DC motor, a rack and pinion gear set, and a photoreflectance sensor positioned beneath the cup hole which aligns under the dispenser.
  • Extra cups are stored in the dispenser until a fresh cup is needed.
  • Cup positioning system positions an empty slot under the dispenser using the method described above.
  • DC motor drives the rack and pinion set to push slowly on the top of the stack of cups. This method is pretty helpful to distribute rack force using a circular disk attached to rack-cup interface.
  • When photoreflectance sensor under cup hole senses that the press has pushed one cup into the slot, the motor is instructed to stop.
  • The other motor, which is attached to the pulley, is then utilized to rotate the cup under the coffee spout. Again using the photoreflectance sensor and black electrical tape method to determine proper stopping location.

The picture shows the dispenser section with the rack, pinion and DC motor to push the cup into the empty slot.