Express Basket

Express Basket streamlines the grocery shopping experience by utilizing scanners and load sensors to provide a portable self-checkout.


Have you ever gone to the grocery store to buy a few groceries and found that the process took much longer than it should've been? Sure the express line speeds up the process, but we can do better. With the Express Basket, you can easily and efficiently purchase your key items in much less time with just the use of your phone.


Board of Awesomeness

  • Samsung tablet and Microsoft Kinect used to track shoppers
  • Express Basket tackles the same problem while also providing the portable self checkout experience.
  • The lack of tags makes Express Basket a more viable solutions especially in grocery stores

Shopping Buddy

  • Includes a tablet that allows the user to browse all of the grocery store items and scanner to eliminate the checkout process
  • Express Basket's interface is on a smartphone application which will provide the user with a more familiar interface and save on costs.

Standard Self Checkout

  • Standard self-checkout technology that exists at most grocery stores
  • Express Basket aims to mobilize this experience and utilize localization to provide useful functionality.


Hardware Requirements

  • Raspberry Pi 3 (microcontroller)
  • Pressure/Weight sensor
  • Battery
  • USB Fast charging cables/adapter
  • Smart Phone (Android)
    • Camera

Software Requirements

  • Mobile App
    • Barcode Scanner
    • Checkout Integration
    • Fraud Detection
    • Bluetooth Communication

User Experience Requirements

The following requirements would greatly improve the user experience:

  • Easy to check out a basket - Easy Pairing
  • Stable and sleek cart - 3D printed housing
  • Charge the user’s phone - 2 USB port powerbank

System Description

Hardware Components

  1. Load Sensor
  2. The load sensor will be able to detect a range of weights. It will communicate its observed weights to the microcontroller.

  3. Scale
  4. A piece of acrylic is secured over the load sensors to distribute the weight evenly

  5. Power
  6. The Smart Basket will be powered by an onboard battery that is charged using the USB Type-C fast charging specifications. We will also charge the user’s phone on the same battery.

  7. Hx711 Amplifier
  8. A small breakout board for the HX711 IC that reads the changes in the resistance of the load cell in order to calibrate and get accurate weight measurements

  9. Load Sensor Combinator
  10. Bare PCB that combines four load sensors into a standard 4-wire wheatstone configuration

  11. Microcontroller
  12. The microcontroller will be used to orchestrate the usage of all of the sensors and communication with transmitters. It will read and write data from the load sensor, and bluetooth transceiver.

Mobile Application

Barcode Scanner

The application will feature a barcode scanner so the system can easily identify the product and obtain its correct weight. This requires the mobile device in question to have a camera.

Virtual Cart

The mobile application will also maintain a list of items that have been checked into the cart known as the virtual cart. It will list items as well as the current total of the cart. Users will be able to remove items from their virtual cart, by interacting with the app.

Online Checkout

We will be integrating online payment to ease the user’s checkout experience. By leveraging the built-in security of the device, we aim to have an extremely secure point of sale.

Basket Integration

The application will communicate with the basket via bluetooth. When the app scans a barcode, it will record the item’s expected weight, then let the user and the basket that the product should be weighed. Upon weighing the product the microcontroller will read from the weight sensor and report the weight via the bluetooth transceiver back to the phone. The phone will then verify the actual weight by comparing it to the expected weight of the product. If the product is of the correct weight, the product is added to the virtual cart.

System Architecture

Use Cases

Initial Interaction

Adding Item

Removing Item