Introduction
Why This Project
Circuit Connections
How It Works
Programming
Designing a Professional Enclosure With JUSTWAY
Manufacturing Services Available
Results
Future Improvement
Conclusion

Published June 27, 2026 © GPL3+

How to Interface MFRC522 RFID Reader with the ESP32-S3-BOX

Build a touchscreen RFID scanner with the ESP32-S3-BOX-3 using LovyanGFX, displaying RFID card UIDs instantly on the built-in display.

BeginnerFull instructions provided5

How to Interface MFRC522 RFID Reader with the ESP32-S3-BOX

Things used in this project

Hardware components

Espressif ESP32 S3 Box3

Jumper wires (generic)

RFID reader (generic)

Software apps and online services

Arduino IDE

Story

Introduction

The ESP32-S3-BOX-3 is one of the most feature-packed ESP32 development boards available today. It combines a high-resolution capacitive touchscreen, Wi-Fi, Bluetooth, audio support, and a powerful dual-core ESP32-S3 processor into a single compact development platform.

While many examples demonstrate its display or AI capabilities, there are very few projects showing how to integrate external SPI peripherals like the MFRC522 RFID reader alongside the built-in display.

Since both the display and the RFID reader rely on SPI communication, many beginners assume they cannot be used together. In reality, with proper SPI initialization and chip-select handling, both devices can work seamlessly on the same ESP32-S3.

In this project, we'll build a simple RFID scanner that reads the UID of any RFID card and displays it instantly on the ESP32-S3-BOX-3 touchscreen using the LovyanGFX graphics library.

Why This Project?

The ESP32-S3-BOX-3 is rapidly becoming one of the most popular development boards for embedded GUI applications.

However, one challenge that many developers face is integrating additional SPI peripherals without interfering with the onboard display.

This project demonstrates a clean and reliable method to connect an MFRC522 RFID reader while continuing to use the BOX-3 display normally.

The same approach can later be expanded into projects such as:

RFID Attendance System
Smart Door Lock
NFC Login Terminal
library Management
Smart Inventory Tracking
Industrial Access Control

Circuit Connections

MFRC522 ESP32-S3-BOX-3

SDA GPIO10

SCK GPIO12

MOSI GPIO11

MISO GPIO13

RST GPIO9

VCC 3.3v

GND GND

How It Works

When an RFID card is placed near the MFRC522 module, the reader captures the card's unique identifier (UID).

The ESP32-S3 reads this UID over SPI and immediately displays it on the touchscreen while simultaneously printing it to the Serial Monitor.

Although both the display and RFID reader use SPI communication, they coexist without conflict because each device uses its own chip-select line.

This makes it possible to build much larger touchscreen applications while continuing to use external SPI peripherals.

Programming

The project is written using the Arduino IDE

The following libraries are used:

LovyanGFX
MFRC522v2
SPI

LovyanGFX handles the onboard display while the MFRC522v2 library communicates with the RFID reader.

After initializing both devices, the program continuously waits for a new RFID card. Whenever a card is detected, its UID is converted into a hexadecimal string and displayed on the screen.

Designing a Professional Enclosure With JUSTWAY

Although the RFID scanner works perfectly on a breadboard, If you wanted the final prototype to look more like a finished product than a development setup. A custom enclosure not only protects the electronics but also improves portability, cable management, and the overall presentation of the project during demonstrations.

To build the enclosure, I designed the parts in CAD and had them manufactured through JUSTWAY. Instead of manually fabricating the enclosure, using a professional manufacturing service resulted in a much cleaner finish and ensured that the ESP32-S3-BOX-3, RFID module, and wiring all fit together accurately.

One feature I particularly appreciate is the instant online quotation system. After uploading the CAD files, the platform automatically generates pricing and allows you to customize materials, colors, surface finishes, and manufacturing processes without waiting for manual quotations.

Another useful feature is their free Design for Manufacturability (DFM) review, which helps identify issues such as thin walls, unsupported features, or tolerance problems before production begins. Catching these issues early can save both time and material, especially when working on functional prototypes.

For this project, 3D printing was the ideal manufacturing method because it allowed me to quickly produce a durable enclosure while preserving the fine details of the design. However, if the project evolves beyond a prototype, JUSTWAY also offers several manufacturing options that make scaling much easier.

Manufacturing Services Available

3D Printing – Rapid prototyping using multiple materials including PLA, ABS, Resin, Nylon, PETG, and engineering plastics.
CNC Machining – Precision machining for aluminum, brass, stainless steel, copper, plastics, and other engineering materials.
Sheet Metal Fabrication – Laser cutting, bending, welding, and finishing for custom enclosures and brackets.
Injection Molding – Suitable for large-scale manufacturing with consistent quality and excellent repeatability.
Urethane Vacuum Casting – Ideal for producing small batches of production-quality parts before investing in injection molds.
PCB Manufacturing – Multi-layer PCB fabrication with various finishes, solder mask options, and quality inspection.
PCB Assembly (PCBA) – Complete SMT and through-hole assembly services, making it possible to receive fully assembled circuit boards.
Rapid Prototyping Services – Fast iteration cycles with engineering support to refine designs before mass production.

One aspect that makes the platform especially convenient is that all these services are available through a single workflow. As a project grows from a simple prototype into a production-ready product, there is no need to switch between different manufacturing vendors.

Whether you're building a one-off hobby project, preparing a prototype for a competition, or planning to manufacture a product in larger quantities, having access to multiple fabrication technologies under one platform significantly simplifies the development process while maintaining professional quality.

Results

The RFID scanner successfully detects multiple RFID cards and displays their unique identifiers instantly on the ESP32-S3-BOX-3 display with virtually no noticeable delay.

At the same time, the UID is printed to the Serial Monitor, making debugging and integration with larger projects much easier.

This simple project serves as a solid foundation for more advanced embedded systems involving authentication, attendance, inventory management, and IoT.

Future Improvement

This project can easily be extended with:

Wi-Fi Database Logging
Google Sheets Integration
MQTT Support
Touchscreen Menus
User Databse
Access Control
NFC Authentication
Cloud Dashboard
Thermal Printer Support

Conclusion

Interfacing an MFRC522 RFID reader with the ESP32-S3-BOX-3 is much simpler than it first appears. By properly configuring the SPI interface and using LovyanGFX for the onboard display, both peripherals can operate simultaneously without conflict.

Although this project is intentionally minimal, it provides a reliable starting point for anyone looking to build more sophisticated RFID-enabled embedded systems using the ESP32-S3 platform.

Code

#include <Arduino.h>
#include <SPI.h>

#define LGFX_ESP32_S3_BOX_V3
#include <LGFX_AUTODETECT.hpp>
#include <LovyanGFX.hpp>

#include <MFRC522v2.h>
#include <MFRC522DriverSPI.h>
#include <MFRC522DriverPinSimple.h>

// ================= DISPLAY =================
static LGFX lcd;

// ================= RFID PINS =================
#define SS_PIN    10
#define SCK_PIN   12
#define MISO_PIN  13
#define MOSI_PIN  11

// ================= RFID =================
MFRC522DriverPinSimple ss_pin(SS_PIN);

SPIClass RFID_SPI(FSPI);

MFRC522DriverSPI driver{ss_pin, RFID_SPI};

MFRC522 mfrc522{driver};

String getUIDString()
{
  String uid = "";

  for (byte i = 0; i < mfrc522.uid.size; i++)
  {
    if (mfrc522.uid.uidByte[i] < 0x10)
      uid += "0";

    uid += String(mfrc522.uid.uidByte[i], HEX);
  }

  uid.toUpperCase();
  return uid;
}

void setup()
{
  Serial.begin(115200);

  // Display
  lcd.init();
  lcd.setRotation(1);
  lcd.setBrightness(255);

  lcd.fillScreen(TFT_BLACK);
  lcd.setTextColor(TFT_WHITE);
  lcd.setTextSize(2);

  lcd.drawString("SCAN RFID CARD", 50, 40);

  // RFID
  RFID_SPI.begin(
    SCK_PIN,
    MISO_PIN,
    MOSI_PIN,
    SS_PIN
  );

  mfrc522.PCD_Init();

  Serial.println("================================");
  Serial.println("RFID READY");
  Serial.println("SCAN A CARD...");
  Serial.println("================================");
}

void loop()
{
  if (!mfrc522.PICC_IsNewCardPresent())
    return;

  if (!mfrc522.PICC_ReadCardSerial())
    return;

  String uid = getUIDString();

  // Serial Monitor
  Serial.println();
  Serial.println("CARD DETECTED");
  Serial.print("UID : ");
  Serial.println(uid);
  Serial.println("----------------------");

  // Display
  lcd.fillRect(0, 90, 320, 120, TFT_BLACK);

  lcd.setTextColor(TFT_GREEN);
  lcd.drawString("CARD DETECTED", 40, 90);

  lcd.setTextColor(TFT_YELLOW);
  lcd.drawString("UID:", 20, 140);
  lcd.drawString(uid, 20, 170);

  mfrc522.PICC_HaltA();
  mfrc522.PCD_StopCrypto1();

  delay(1000);
}

Credits

Rohan Barnwal

46 projects • 40 followers

Rohan Barnwal - maker, hacker, tech enthusiast. I explore new tech & find innovative solutions. See my projects on hackster.io!

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How to Interface MFRC522 RFID Reader with the ESP32-S3-BOX

How to Interface MFRC522 RFID Reader with the ESP32-S3-BOX

Things used in this project

Hardware components

Software apps and online services

Story

Introduction

Why This Project?

Circuit Connections

How It Works

Programming

Designing a Professional Enclosure With JUSTWAY

Manufacturing Services Available

Results

Future Improvement

Conclusion

Code

Code

Credits

Rohan Barnwal

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