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 provided140

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.

Giving Your Project a Professional Finish

Building a working prototype is often only the first step of any hardware project. Whether you're developing an Arduino project, an ESP32 based IoT device, a robotics system, an embedded application, or even a custom PCB, there eventually comes a point where you want the final build to look clean, organized, and professional

While breadboards and exposed wiring are perfect during development, a custom enclosure protects the electronics from accidental damage, improves cable management, makes transportation easier, and gives the project a polished appearance. For engineering exhibitions, hackathons, client demonstrations, YouTube videos, or commercial prototypes, a professionally manufactured enclosure can make a significant difference in both durability and presentation.

Over the past few months, I've ordered several custom 3D printed parts from JUSTWAY for different electronics projects, and the overall experience has been consistently positive. The printed parts arrived well packed with good dimensional accuracy, clean surface quality, and required very little post-processing before assembly.

From Prototype to Production

One thing I particularly like about JUSTWAY is that it isn't limited to only 3D printing. The platform is designed to support the complete product development cycle—from rapid prototyping to low-volume manufacturing and eventually mass production.

Depending on your application, the platform offers several manufacturing services, including:

3D Printing for rapid prototyping, concept models, custom enclosures, and functional mechanical parts.
CNC Machining for precision components manufactured from aluminum, stainless steel, brass, titanium, copper, and engineering plastics.
Sheet Metal Fabrication for industrial enclosures, mounting brackets, control panels, and structural assemblies.
Injection Molding for producing large quantities of plastic parts with consistent quality.
Silicone Vacuum Casting for producing low-volume production-quality parts without investing in expensive tooling.

According to JUSTWAY, these services support customers ranging from individual makers and engineering students to startups and industrial manufacturers working in consumer electronics, robotics, automotive, aerospace, medical, and industrial automation.

Uploading Your CAD Design

The ordering process is refreshingly simple.

Instead of exchanging multiple emails for quotations, you simply upload your CAD model directly through the online quotation system.

The platform supports several commonly used engineering formats including:

STL
STEP / STP
OBJ

making it compatible with popular CAD software such as Fusion 360, SolidWorks, Autodesk Inventor, Creo, FreeCAD, and Onshape.

Once uploaded, the model is automatically prepared for quotation, allowing you to continue configuring the manufacturing parameters immediately.

For projects containing multiple components, several files can also be uploaded together, making it convenient to manufacture complete assemblies rather than individual parts.

Configuring the Manufacturing Parameters

After uploading the model, the platform provides a detailed configuration panel where almost every manufacturing parameter can be customized before placing the order.

Material Selection

Depending on the manufacturing process, a wide range of materials is available.

For FDM 3D printing, commonly available materials include:

PLA
ABS
PETG
Nylon
TPU
Polycarbonate (PC)
ASA
Carbon Fiber Reinforced Materials
Engineering-grade Thermoplastics

For CNC machining, users can choose from materials such as:

Aluminum 6061
Stainless Steel 304
Brass
Copper
Titanium
Engineering Plastics

Each material offers different characteristics depending on whether the priority is strength, heat resistance, flexibility, surface finish, or dimensional accuracy.

SLA Resin Printing Options

For projects requiring extremely fine details or presentation-quality models, JUSTWAY also offers SLA resin printing with multiple specialized materials.

Available resin options include:

Standard White Resin
Standard Black Resin
Transparent Resin (UTR-8100)
Translucent Resin
High-Temperature Resin
Flexible Resin
Engineering Resin
Tough Resin
ESD-Safe Resin
Dental and Professional Resins

These materials are designed for different applications ranging from display models and transparent covers to engineering validation, electronic fixtures, medical prototypes, and functional mechanical components.

For example:

Transparent Resin is excellent for display windows, LED covers, and visual prototypes.
Engineering Resins provide higher strength and dimensional stability for functional parts.
Flexible Resins are suitable for rubber-like components.
High-Temperature Resins perform better in applications exposed to elevated temperatures.
ESD Resins are useful when manufacturing fixtures for handling sensitive electronic assemblies.

Having access to different resin formulations makes it much easier to choose the right balance between appearance, strength, and functionality.

Color and Finish Options

The platform also allows users to customize the appearance of printed parts.

Depending on the selected material, various colors and finishes are available, including standard colors, silk finishes, matte textures, translucent options, and specialty finishes.

This is particularly useful when manufacturing demonstration models, educational kits, exhibition prototypes, or consumer-facing products where aesthetics are just as important as functionality.

Instant Online Quotation

One feature I personally appreciate is the instant quotation system.

As different materials, quantities, manufacturing technologies, or finishing options are selected, the estimated manufacturing cost updates automatically.

The quotation page also provides useful information such as:

Manufacturing Cost
Shipping Cost
Estimated Delivery Time
Shipping Method
Total Price
Part Weight

Being able to compare multiple material options within a few minutes makes it much easier to optimize both performance and budget before placing an order

Engineering Support Throughout the Process

Beyond manufacturing, JUSTWAY also offers several features that simplify product development.

Their platform provides instant online quotations, design review before production, order management, production tracking, and shipping updates, making it easy to monitor the entire manufacturing process from a single dashboard.

For larger production runs, additional services such as dedicated engineering support, DFM (Design for Manufacturability) review, First Article Inspection (FAI), and quality inspection reports are also available to help ensure consistent production quality.

Final Thoughts

Whether you're building a one-off hobby project, a university engineering project, an open-source hardware design, or preparing a commercial product, custom manufactured parts can significantly improve both reliability and presentation.

Having used JUSTWAY for several of my own projects, I found the platform straightforward to use—from uploading CAD files and selecting materials to receiving an instant quotation and tracking production. Its combination of rapid prototyping, precision manufacturing, and scalable production services makes it a practical solution for makers, students, startups, and professional hardware developers looking to turn their ideas into finished products.

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

52 projects • 41 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

Giving Your Project a Professional Finish

From Prototype to Production

Uploading Your CAD Design

Configuring the Manufacturing Parameters

Material Selection

SLA Resin Printing Options

Color and Finish Options

Instant Online Quotation

Engineering Support Throughout the Process

Final Thoughts

Results

Future Improvement

Conclusion

Code

Code

Credits

Rohan Barnwal

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