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
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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 V3

Caliber V3

New redesign for manufacturing with a multi-board PCB and solderless connections. ESP32 S3 Supermini is not featured in this image for testing antenna interference.

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)