Project Hub /Audio Displays & Interactive Media/LED Matrix & Cube Displays/DIY IoT-enabled Talking Weighing Scale

Intermediate

ESP32

₹1,500 – ₹5,000

3 – 6 Hours

Partial Kit

DIY IoT-enabled Talking Weighing Scale

Build a smart talking grocery scale using an IndusBoard Coin, load cell, and audio amplifier that provides instant voice feedback and logs sales data.

Originally published on ElectronicsForU

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

HX711 Dual-Channel 24 Bit Precision A/D weight Pressure Sensor Out of stock
0.96 Inch I2C/IIC 4pin OLED Display Module White Rs. 349.00
Cable for Arduino Nano (USB 2.0 A to USB 2.0 Mini B) 30cm Rs. 69.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

We don't carry yet: WiFi Module (generic)
Speaker / Audio Amplifier

Browse all components

How It Works

The DIY IoT-enabled Talking Weighing Scale integrates hardware and software to measure weight, display data, and provide audio feedback over a Wi-Fi-enabled microcontroller network. At the core of the system is the IndusBoard Coin WiFi MCU Board, which coordinates data acquisition and processing. Weight is measured using a YZC-133 load cell capable of handling loads from 5kg to 50kg. Because the electrical changes produced by a load cell under pressure are extremely small, an HX711 load cell amplifier module is used to amplify these analog signals and convert them into digital data that the IndusBoard Coin can interpret. Once the microcontroller calculates the precise weight, it sends visual information to a 0.96-inch OLED display using the SSD1306 driver, allowing users to view the measurement clearly. Simultaneously, the system can generate audio prompts or voice feedback by streaming digital audio data through the I2S protocol to a MAX98357 I2S amplifier module. This amplifier drives an 8-ohm mini speaker, translating the digital audio signals into audible speech or sound alerts. Because the IndusBoard Coin features built-in Wi-Fi connectivity, the device can also transmit weighing and sales data over a network for logging or remote monitoring. The entire system is programmed using the Arduino IDE and is powered and flashed via a USB-C cable.

Why Build This

Create an accessible retail checkout or grocery weighing device that offers instant audio feedback for visually impaired users.

Automate inventory and sales data logging in small retail shops using Internet of Things (IoT) connectivity.

Gain practical experience building interactive embedded systems that combine precision analog sensing, visual displays, and digital audio output.

Real-World Application

Retail grocery stores, small shops, and accessible weighing solutions for visually impaired users.

Skills You'll Learn

Load cell signal conditioning

HX711 bridge amplifier interfacing

I2C communication

I2S audio streaming

Wi-Fi data logging

OLED display rendering

Safety Precautions

No specific precautions noted for this build — always follow general electronics safety practices.

Technology Tags

IOT

ESP32

LOAD CELL

HX711

MAX98357

OLED

AUDIO OUTPUT

WEB DASHBOARD

ARDUINO IDE

PCB DESIGN

Frequently Asked Questions

How do I calibrate the YZC-133 load cell with the HX711 amplifier?

You will need to use a known reference weight (such as a standard calibration weight) in your Arduino sketch to map the raw digital values read from the HX711 module to accurate mass units like grams or kilograms.

Can the system generate actual voice words without an external internet connection?

Yes, depending on how you program the microcontroller in the Arduino IDE, you can store pre-recorded audio samples or tone frequencies in memory to play simple spoken numbers and alerts through the MAX98357 amplifier and mini speaker.

What is the purpose of the USB-C cable in this project?

The USB-C cable is used both to supply power to the IndusBoard Coin during testing and to upload your compiled Arduino code from your computer to the microcontroller board.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

PRJ-01581