Project name: Care Dispenser
Project by: Vishal
Abstract:
Menstrual hygiene is a fundamental need, yet immediate access to sanitary products on campus and even in nearby areas students are left with no quick or dignified way to access sanitary pads when needed. My project set out to solve this problem by engineering a modern, reliable, and fully cashless IoT vending machine from the ground up. I designed the complete mechanical and electronic systems, developed a user-friendly web application for payment, and built a cloud-based backend to connect it all. This report documents the journey from a simple idea to a fully functional, deployed product that provides a seamless and dignified solution for students.
1. Introduction & Objectives:
Solving a Real-World Problem
The core objective of this project was to address the critical lack of access to sanitary products on campus. I aimed to design, manufacture, and deploy a fully functional, cashless vending machine to provide a reliable and dignified solution for students.
The key goals were:
► Create Access: To build the first on-campus, 24/7 source for sanitary pads.
► Ensure Privacy & Dignity: To develop a fully digital and cashless system, allowing private and quick purchases via smartphone.
► Guarantee Reliability: To engineer a robust mechanical and electronic system that works every time.
2. System Architecture & Design
I structured the project into three parts, each part was modular and robust. This model separates the user interface, the backend logic, and the physical hardware.
► The Frontend (Web Application): The user-facing website built with HTML, CSS, and JavaScript, allowing for product selection and payment.
► The Backend (Cloud Infrastructure): A secure, serverless system using Firebase Functions to handle sensitive operations like payment verification with Razorpay.
►The Hardware (IoT Device): The physical machine, controlled by an ESP32 microcontroller, that dispenses the product.
3. Technical Implementation
3.1 Mechanical Design & Manufacturing
To design and oversee the fabrication of a compact, durable, and serviceable 4-channel smart vending machine enclosure with precise component integration.
Engineering Drawing to Physical Product
► Engineering Drawing:
Initiated the design with a full set of manual 2D drawings.
Utilized orthographic projections (top, front, side) and isometric views to define the machine's fundamental structure and component layout.
Overall Cabinet.
Front Door Assembly.
Merchandise Display Window.
Internal Shelves (4 Channels).
Pickup Box (Dispensing Bay).
► Digital for Fabrication (Laser Cutting Sketches):
Translated hand drawings into 2D sketches in laser cutting software to generate the flat patterns for sheet metal fabrication.
Applied DFM principles by standardizing bend radii and hole sizes to ensure cost-effective manufacturing.
► Geometric Dimensioning & Tolerancing (GD&T):
Applied fundamental GD&T controls to ensure precise alignment of the motor-spiral mechanism, which is critical for preventing product jams.
The positional tolerance of motor mounting holes was controlled relative to shelf datum planes to guarantee shaft perpendicularity.
A general profile tolerance of ±0.5mm was specified for all fabricated components.
► Material Selection:
Cabinet Material: 1.5mm CRCA (Cold Rolled Close Annealed) Mild Steel was selected for its excellent formability, weldability, and superior surface finish.
Finishing Process: A 7-tank powder coating process was specified for a professional finish and long-term corrosion resistance.
► Bill of Materials (BOM):
Compiled a detailed BOM listing all 52 components for the assembly.
This included custom fabricated sheet metal parts, standard fasteners (M4 screws), and procured items like the motor-spiral assemblies ► Final Specifications: The final manufactured design is 85cm (H) x 55cm (W) x 20cm (D). The core of the machine is the 4-channel spiral dispensing mechanism, with each spiral engineered with a 22mm pitch to perfectly hold and dispense a standard sanitary pad.
► The final design is 85cm (H) x 55cm (W) x 20cm (D), built from powder-coated mild steel.
3.2 Electronics & Hardware Integration Bringing the Machine to Life The electronics bridge the digital commands and the mechanical action.
► The Brain: An ESP32 microcontroller was chosen for its built-in Wi-Fi, allowing a direct connection to the cloud.
► The Muscle: Two L298N Motor Drivers were used to handle the high power requirements of the four 12V DC Gear Motors. These drivers take low-power signals from the ESP32 and use them to switch the main 12V supply to the motors.
3.3 Software & Cloud Implementation The Full-Stack Experience The software makes the machine "smart". I developed the entire full-stack application.
**► Website:**Created a simple and intuitive website useing HTML, CSS, JavaScript, This website allows users to select a product and complete the payment securely.
► The Cloud Connection: To handle payments and commands, I used Google's Firebase platform. A secure cloud function verifies each transaction with Razorpay. After a successful payment, the app sends a signal through the Firebase Realtime Database directly to the vending machine.
4. My Project Journey:
From an Idea to a Real-World Solution
► The Payment System:
► Hardware Integration:
► Manufacturing:
5. ► Future Scope:
From Prototype to Product
Evolving the Design for the Real World After building this first machine, I identified several key improvements to make it a true, market-ready product. My future plans are focused on enhancing the mechanical design, intelligence, and software.
► Mechanical & Design Enhancements
► Software and Analytics
6. Conclusion
This project successfully demonstrates a complete, end-to-end IoT solution for a real-world problem. By integrating a modern web application with a secure, serverless backend and custom-programmed hardware, I was able to create a reliable, cashless, and user-friendly vending machine. The journey reinforced the importance of robust architecture, systematic debugging, and the potential for technology to create practical and dignified solutions.