Pill Dispenser
Engn 1931D Design of Mechanical Assemblies - December 17, 2024
Collaborated in a team of six to design a low-tech, user-friendly pill dispenser. The device incorporates auditory and visual cues, straightforward setting controls, and a simple weekly refill system to promote independent and accurate medication management—without relying on a caregiver or smartphone. The project emphasized the hands-on assembly of mechanical components and an iterative prototyping process to develop a fully functional and accessible device.
Problem Statement
Many individuals need to take medication on a regular basis, but physical or cognitive challenges—and limited access to caregivers—can make this difficult. How might we support users of all language backgrounds in taking the correct dosage at the right time through a straightforward, intuitive, accessible, and low-tech solution that helps reduce health risks?
List Title
Requirements
Definition
1 / Easy Mechanical Operation (5)
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Minimal movement/pressure: one press or no press, single place to acquire pills, spring loaded button
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Little to no tech involved: no app or cord (either can be easier depending on audience)
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Easy to refill at the beginning of the week: auto distribution mechanism
2 / Auditory Aids (5)
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Auditory cues for reminder Give reminders for multiple times (people need to take medications at different times)
3 / Manufacturability (5)
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Easy and accessibly manufacturable
4 / Visual Aids (4)
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Visual cues for reminders
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High contrast for visibility
5 / Organization (5)
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Divide slots by day or by medication type
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Automatic organization
6 / Cost < $60 (3)
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Should be under $60
7 / Size restrictions (3)
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Pill outlet at least 2*2” for easy pick-up
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Total size: Less than 8” x 8”
8 / Weight restrictions (2)
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< 5 lb
9 / Modularity (1)
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Should be able to adapt for travel
10 / Blade for cutting pills (0)
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Blade should use a hidden design and shouldn't hurt the user by accident
Ideation
Early Prototyping
Assembly & Component Drawings
Final Protoype
Our final prototype features
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Six modular pill containers mounted on a rotating platform, each capable of dispensing a scheduled dose. The rotating mechanism is powered by servo motors and controlled by an Arduino.
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Auditory and visual reminders, using tactile push buttons with symbolic icons (check mark, arrow, etc.) for intuitive interaction regardless of language.
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Simple, tool-free weekly refill system with easily swappable lids and containers to streamline the caregiver's or user’s refill process.
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Large tactile buttons and a backlit interface to improve accessibility for users with visual or dexterity impairments.
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Funnel-based dispensing mechanism for accurate pill delivery into a tray, reducing the chance of spills.
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Minimalist, approachable enclosure designed with a clear layout of openings for the speaker, display, buttons, and pill drawer.
Arduino Code
1 / Capabilities
The code
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Allows user to configure pill dispensing amounts for all compartments.
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Dispenses the set amount pills once every 12 hours.
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Allows user to reset the system to default settings.
2 / Hardware Components
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Increase/Decrease Buttons: Adjusts pill amounts in each compartment.
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Left/Right Buttons: Navigate between the three modes.
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Confirm Button: Confirm actions in modes.
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LED & Buzzer: Provide visual and auditory cue.
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Servo Motors: Control pill dispensing for all compartments.
3 / Mode 0
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Setting Pill Amounts Adjust pill amounts using Increase/Decrease buttons. Press durations are tracked to count button presses. Holding a button will increase/decrease the amount of pills added.
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Every 12 seconds, the system updates the current motor's pill amount and switches to the next motor to allow pill amount adjustments in every compartment.
4 / Mode 1
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Interval Dispensing Activate interval-based pill dispensing by pressing the Confirm button.
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Pills are dispensed at regular intervals (12 hours, defined in variable pillIntervalMillis) and immediately upon activation when pressing the confirm button in mode 1.
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Each motor dispenses pills based on the preconfigured amount (pillAmounts[i]) and turns 500ms per pill to control dispensing time for precision.
5 / Mode 2
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Reset System Resets the pill amounts to their default values (1 pill). Deactivates interval dispensing.
Further Improvements
1 / Integration of Real-Time Clock (RTC)
To enable accurate, scheduled dispensing aligned with real-world time, the system could be upgraded with an RTC module (e.g., DS3231) and RTClib integration. This would allow users to set specific times for pill release rather than relying on internal timers.
2 / Optimization of Hardware Architecture
Switching to the Arduino DUE offers greater pin availability, but future iterations could benefit from custom PCBs and more compact hardware integration. This would reduce wiring complexity and improve durability beyond breadboard-based builds.
3 / Enhanced Display Functionality
The current e-ink display has limited support for text and graphics. Future development could involve using a more responsive screen or alternative displays that support clearer affordances like icons, visual instructions, or feedback animations for improved accessibility.
4 / Flexible Scheduling for Multiple Medications
Enabling independent time intervals for each compartment would support more personalized medication routines. This would require real-time tracking and a more advanced scheduling interface.
5 / Improved User Interaction for Setup
Currently, pill amount adjustments are limited to a fixed 12-second window per compartment. Adding dedicated buttons for motor switching or creating a more flexible UI would make the setup process more intuitive and accessible.
Final Design
The final design reflects the focus on mechanical simplicity, user independence, and language accessibility in both the interface and internal components.
