Project Hub /Basic Analog & Power Electronics/How to scan QR Codes using ESP32-CAM module?

Intermediate

ESP32

₹500 – ₹1,500

3 – 6 Hours

Complete Kit

How to scan QR Codes using ESP32-CAM module?

Learn how to build a cost-effective QR code scanner using an ESP32-CAM module, a push button, and an OLED display communicating with a cloud API.

Originally published on CircuitDigest

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.

ESP32 CAM WiFi Module Bluetooth with OV2640 Camera Rs. 810.00
0.96 Inch I2C/IIC 4pin OLED Display Module White Rs. 349.00
2-Slot 18650 Holder with Protective Cover and On/Off Switch – Case Rs. 109.00
USB to UART/ESP8266 Adapter Programmer for ESP-01 WiFi Modules with CH340G Chip Rs. 99.00
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
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

Browse all components

How It Works

This embedded system operates by capturing visual data through the ESP32-CAM module and processing it to decode embedded information. When the user positions a QR code in the camera's field of view and presses the tactile push button, the ESP32 microcontroller captures the image frame. Because the ESP32 features built-in Wi-Fi and processing capabilities, it can parse the image data or transmit it to a cloud-based API for decoding. Once the data is successfully retrieved or processed, the microcontroller communicates with the 0.96-inch OLED display via I2C protocol, rendering the decoded text, URL, or identification string onto the screen for the user to view. The USB to UART converter is utilized during the initial setup phase to program the ESP32-CAM from the Arduino IDE, acting as the physical bridge for serial communication and firmware flashing. The entire circuit is integrated on a breadboard using jumper wires to route power and data signals between the components.

Why Build This

Design a functional Internet of Things (IoT) edge device capable of optical data capture and cloud communication.

Implement a human-machine interface combining a physical tactile trigger, a camera sensor, and a graphical display.

Develop real-world automation prototypes applicable to smart retail, inventory control, and event access systems.

Real-World Application

Smart shopping carts, automated vending machines, inventory tracking, and event check-in systems.

Skills You'll Learn

Camera module interfacing

I2C communication protocol

Serial UART programming

Cloud API integration

Debouncing push buttons

Embedded display rendering

Safety Precautions

Ensure proper wiring and avoid short-circuiting the power supply pins when connecting the USB to UART module.

Technology Tags

ESP32-CAM

ARDUINO

IOT

QR CODE

OLED DISPLAY

HTTP

CLOUD API

C++

COMPUTER VISION

Frequently Asked Questions

Why do I need a USB to UART converter if the ESP32-CAM has a built-in camera?

The ESP32-CAM module lacks an onboard USB port to keep its footprint small and cost low. A USB to UART converter is required to connect the board to your computer via USB for uploading code from the Arduino IDE.

How does the OLED display connect to the ESP32-CAM?

The 0.96-inch OLED display typically communicates using the I2C protocol, meaning it connects to designated SDA and SCL pins on the ESP32-CAM alongside power and ground.

Can this project scan QR codes without an internet connection?

While basic decoding can sometimes be handled locally depending on library implementations, many standard implementations rely on a Wi-Fi connection to query a cloud API for robust image processing and data retrieval.

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-01019