Caliber (Smart Nutrition Scale)

Manufacturing-ready smart nutrition scale with custom multi-board PCB, load-cell sensing, barcode scanning, and a connected app.

C++ESP32KiCadAWS IoTMQTTReact Native
Back to Projects

Overview

Smart nutrition scale that automatically logs food and nutrition by combining load-cell sensing, barcode scanning, and a connected React Native app.

Designed and fabricated a manufacturing-ready scale with a custom multi-board PCB, sourcing components and negotiating with suppliers to reduce BOM cost.

Implemented C++ firmware on ESP32 with an AWS IoT/MQTT cloud backend connecting the device to the companion app.

Media

Caliber demo

V2 prototype shown in the demo video

Highlights

  • Every item scanned seamlessly with the built-in barcode reader.
  • All scanned items tracked automatically with no further input required.
  • Clean exterior design with an integrated display and tactile controls.
  • App and scale demonstrated live communication over the cloud backend.
  • End-to-end workflow shown from scan and weigh to nutrition logging in the app.

Next steps

  • ESP32 S3 Supermini antenna testing
  • Beta testing
  • Initial fundraising

Development

Caliber V2

Caliber V2

Electrical wiring and components of the module shown in the demo video.

Caliber V4

Caliber V4

New redesign for manufacturing with a multi-board PCB and solderless connections. Top plate removed for visibility.

Updated BOM

PCB bill of materials only. Enclosure, fasteners, and other assembly parts are not listed.

Motherboard

  • ESP32 S3 Supermini
  • M5Stack Mini Scales Module
  • 1kΩ Resistor
  • 10kΩ Resistor (×3)
  • 100kΩ Resistor
  • MOSFET P-CH 30V 4A

Daughterboard

  • 0.1 µF capacitor (×3)
  • 47 µF capacitor (×1)
  • 100 µF capacitor (×1)
  • 2.4" TFT LCD Display
  • EMT8120AD Barcode Scanner Module
  • Push Buttons (×3)