DUEN Drink Dispenser (DDD)

The Spring 2024 cohort "Lil Maxies" built the DUEN Drink Dispenser (DDD), a wooden drink dispenser controlled via a React web app. Users place a cup under the dispenser, navigate to the website, input their cup volume, select from available drinks (Water, Apple Juice, Cranberry Juice, Lemonade), choose percentage splits, and click Dispense. An Arduino Uno R4 WiFi receives the request and triggers motorized ball valves and a peristaltic pump to dispense the exact drink blend. The wooden casing was custom-built using a table saw, wood glue, and drilled holes for tubing and wiring.

• —App-controlled dispensing via React website and Arduino Uno R4 WiFi
• —Peristaltic pump at 500ml/min with motorized ball valves for precise drink selection
• —Supports drink blending with user-defined percentage splits
• —Custom wood casing with CAD-designed electronic enclosure
• —Completed within budget ($444.15 of $450 after refunds)

• —React
• —Arduino IDE
• —CAD (SolidWorks)

• Apr 21Brainstorm week — introduced to construction project, brainstormed proposals and presented three ideas.
• Apr 28Planning and designing — cohort started planning and designing after construction project was revealed.
• May 5Planning and buying materials — began purchasing materials.
• May 12Constructing project — cohort began constructing the final build to present on May 18th.

• —Prototyping: Drew and edited blueprints based on design needs and component sizes. Built cardboard prototype to finalize dimensions, focusing on functionality and portability.
• —CAD Modeling: Designed electronic box, railings for glass and wood slide, and nosal for tube. Updated designs for electronics safety and pump mounting.
• —Woodworking: Cut wood using table saw based on prototype dimensions. Assembled with wood glue. Drilled holes through shelves for tubing and electrical wires.
• —Electronics: Arduino Uno R4 WiFi integrated with React web app via built-in WiFi. 12V power supply stepped down to 5V via buck converter. 8-channel relay controls valves and pump. Flyback diodes protect against back-EMF.
• —Water system: Peristaltic pump at 500ml/min moves liquid through silicone tubing and Y-shaped connectors. Motorized ball valves control drink selection. Tubes heated with hairdryer for secure connections.
• —App/Website: React web app allows users to input cup volume, select drinks, choose percentage splits (25/50/75/100%), and dispense. Confirmation screen shown after successful dispense.

• Problem: Total spending of $507.51 exceeded the $450 budget.

  Solution: Pursued returns on eligible items, bringing effective cost to $444.15 — $5.85 under budget after refunds.

• Problem: Electronics at risk of liquid splash from tubing.

  Solution: Positioned the electronic board away from splash zones; used careful mounting and routing.

• Problem: Securing silicone tubing to connectors.

  Solution: Used a hairdryer to heat and expand tubes for a tight, secure fit onto barbed adapters.

• —4 Motorized Ball Valves
• —12V Power Supply
• —Wood
• —Peristaltic Pump
• —Arduino Uno R4 WiFi
• —Barbed Adapters
• —4-Pack Containers
• —Buck Converter (12V to 5V)
• —8-Channel Relay
• —Silicone Tubing
• —Y-Shaped Connectors
• —Flyback Diodes
• —Killswitch
• —Breadboard
• —Wood Glue

Total cost: $444.15

• 01Ensure your cup is placed under the dispenser nozzle.
• 02Navigate to the website on your phone or device.
• 03Input the volume of your cup (in ml) and click Go.
• 04Select your desired drink(s) from the available options: Water, Apple Juice, Cranberry Juice, or Lemonade.
• 05Choose your desired fill percentage (25%, 50%, 75%, or 100%). Multiple drinks can be selected with percentage splits.
• 06Click "Dispense" to begin. Wait for the confirmation screen: "Your drink has been successfully dispensed!"
• 07Enjoy your beverage! Click "Make another drink" to start over.