HopCart

Inspiration

Grocery shopping often feels less like shopping and more like searching. Large supermarkets can carry tens of thousands of items, and shoppers frequently wander through aisles trying to locate products. This leads to backtracking, wasted time, and unnecessary fatigue.

Our team wanted to rethink the grocery experience by asking a simple question:

What if grocery shopping worked like Google Maps?

Instead of wandering through a maze of aisles, shoppers could enter their grocery list and follow an optimized route through the store.

This idea led to HopCart, an autonomous grocery cart that guides shoppers along the most efficient path to collect their items.

Beyond convenience, we were also inspired by accessibility. For elderly shoppers, people with mobility challenges, or anyone navigating large stores, reducing unnecessary walking can make a meaningful difference.

What it does

HopCart is an autonomous grocery cart that guides shoppers through the fastest path in a store.

Users enter their grocery list into a mobile interface. The system then:

Maps each item to its location in the store
Computes an optimized route through the store layout
Guides the shopper aisle by aisle using the cart

The result is a clear path from entrance to checkout, minimizing backtracking and unnecessary walking.

In practice, HopCart helps:

Reduce time spent searching for items
Lower physical fatigue from wandering aisles
Improve store navigation for accessibility
Create smoother traffic flow in busy stores

Instead of circling the store, shoppers simply follow the cart’s route.

How we built it

We built HopCart as a hardware + software prototype during the hackathon.

Hardware

The physical cart prototype includes:

Arduino microcontroller
Stepper motors for cart movement

This allows the cart to physically demonstrate guided navigation.

Software

The navigation system works in several steps:

Grocery List Input Users enter items into a mobile interface.
Store Map Graph The store layout is modelled as a graph where nodes represent key locations (aisles, intersections, entrance).
Route Optimization The backend calculates an efficient path through the store based on item locations.
Cart Guidance The optimized route is sent to the cart, which guides the user along the path.

Conceptually, the routing problem resembles a shortest-path optimization problem across a graph of store locations.

Sponsor Technologies Used

To bring HopCart to life, we integrated several sponsor technologies across our hardware, software, and user experience.

ElevenLabs

We used ElevenLabs to generate natural voice directions for shoppers as they navigate the store. Instead of reading text instructions, users receive clear spoken guidance such as “Turn left to aisle 4 for dairy products.” This makes the navigation system more intuitive and accessible, especially for users who may prefer audio guidance.

Lovable

We used Lovable to build the frontend of our web application. Lovable allowed us to quickly prototype a clean interface where users can input their grocery lists, visualize the store map, and see their optimized shopping route. This helped us rapidly design and deploy a usable UI during the hackathon.

Google Gemini API

We integrated the Google Gemini API to provide grocery list insights and nutritional information. When users enter items into their shopping list, Gemini can surface helpful context such as nutritional facts or dietary insights, helping shoppers make more informed choices.

1Password

Users log in with email and password through Supabase Auth, which hashes passwords with bcrypt and issues encrypted JWT tokens. Sessions auto-refresh so users stay logged in, and every page checks for a valid session, if you're not authenticated, you get redirected to the login screen immediately. We also enforce a minimum password length, let users toggle password visibility so they can verify what they're typing, and show a clear "Encrypted & private" badge on the login page so they know their credentials are protected.

Together, these tools helped us build HopCart as a complete system combining hardware navigation, intelligent software, and user-friendly interfaces.

Challenges we ran into

Building a physical prototype within a short hackathon timeline came with several challenges.

Hardware constraints Initially, we planned to build a fully autonomous wheeled robot (a completely different idea), but finding the right motors and wheel setup proved difficult during the event. We pivoted to a mini cart prototype using available components. This was also the first time any of us on the team have experimented with hardware.

Mapping a grocery store Real stores are complex environments with constantly changing layouts. For the demo, we simplified the store into a structured graph of aisles and intersections.

Route optimization logic Determining an efficient path between multiple items while maintaining a logical shopping flow required experimenting with routing strategies.

Hardware-software integration Connecting the route logic to the Arduino-driven cart required debugging communication between the software navigation system and the physical prototype.

Accomplishments that we're proud of

Building a working hardware prototype, not just a concept
Designing a route optimization system for grocery navigation
Demonstrating a full pipeline from shopping list → optimized path → cart guidance
Successfully pivoting when our original hardware plan changed
Creating a system that addresses both convenience and accessibility

What we learned

This project taught us a lot about building end-to-end systems under tight time constraints.

We learned how to:

Translate a real-world problem into a graph-based optimization problem
Rapidly prototype hardware and embedded systems
Integrate route planning algorithms with physical robotics
Adapt our approach when hardware constraints forced a pivot

We also learned how powerful good user experience design can be. A simple change—turning grocery shopping into a guided route—can drastically improve the experience.

What's next for HopCart

Our hackathon prototype demonstrates the concept, but there are many opportunities to expand HopCart further.

Future directions include:

Mobile App Experience

Due to the time constraints of the hackathon, we focused our development efforts on the hardware prototype and routing system, so the mobile app was designed but not fully implemented.

Real store integration Partnering with grocery stores to use actual store maps and inventory locations.

Indoor positioning systems Using sensors or computer vision to track the cart’s location inside large stores.

Accessibility features Supporting shoppers with mobility challenges through easier navigation and fatigue reduction.

Store analytics Providing retailers with insights into traffic flow and aisle congestion.

Personalization Integrating promotions, preferences, and dietary filters into the route planning system.

Our long-term vision is for route guidance to become the operating system of physical retail, helping both shoppers and stores navigate the complexity of modern supermarkets.