Real-Time Digital Information Display Using LED Matrix with Wireless Control via BLE and ESP32
WHAT IS LED MATRIX
Tools and Materials
How It Works
Conclusion
Example Results

Team UHUY LED PARTNER:

Muhammad Rio Agustan 77

•

Muhammad Allen

•

Ananda Agung Styadi 69062

•

Rayhan_Rahmatullah113

•

Hendra Kusumah

Published May 15, 2025

LED Matrix Information Board Via Bluetooth

Designed to display real-time scrolling text that can be directly controlled via Bluetooth.

BeginnerProtipOver 2 days92

LED Matrix Information Board Via Bluetooth

Things used in this project

Hardware components

Seeed Studio XIAO ESP32S3 Sense

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Jumper Wire Kit, Machine Pin

Story

Real-Time Digital Information Display Using LED Matrix with Wireless Control via BLE and ESP32

Real-Time Digital Information Display Using LED Matrix with Wireless Control via BLE and ESP32. Users simply send text from a smartphone through the BLE Scanner application, and the text will immediately be displayed as scrolling text on the LED Matrix screen. This system operates in real-time and does not require any wired connection to change the message content.

Thanks to its success, the LED board can be utilized for various purposes such as name displays, announcements, or digital notifications in both public and private spaces. The display can be changed at any time quickly and conveniently through a BLE connection.

WHAT IS LED MATRIX?

LED Matrix is an array of LED (Light Emitting Diode) lights arranged in a grid or matrix form—usually square-shaped with rows and columns, such as 8x8, 8x32, or 16x64. Each point (or pixel) in the matrix is a single LED that can be turned on or off in a controlled manner.

The function of this LED Matrix-based digital information board is designed to display scrolling text in real time, which can be directly controlled via a smartphone. This system uses the ESP32 microcontroller, which features Bluetooth Low Energy (BLE) connectivity, allowing users to send text wirelessly.

With the convenience of operation via smartphone only, this device is highly suitable for use in various places such as waiting rooms, stores, classrooms, exhibitions, and offices, to deliver information quickly and efficiently. This technology offers high flexibility in changing messages instantly and practically whenever needed.

Tools and Materials

This is picture Tools and Materials

1. ESP32 (XIAO ESP32-S3)

2. 4-in-1 LED Matrix (with MAX7219/FC16 chipset)

3. Jumper wires

4. BLE Scanner application on Android / iOS

5. Cardboard box

6. USB Type C Cable

How It Works

1. Connect the jumper wires to the MCU and LED matrix according to the pins.

2. Create a code as planned, using Bluetooth functionality.

3. Run the code and upload it to the MCU.

4. Download the NRF Connect app.

5. Turn on your phone's Bluetooth, then create any desired text.

Conclusion

This project demonstrates that a combination of ESP32 and LED Matrix can be used to build a smart, energy-efficient, and user-friendly information board. Through BLE connectivity, users can instantly update the message content directly from a mobile device.

Example Results

"This photo shows the result of what we have built. Here, the smartphone used can be either Android or iOS, and the text displayed can be changed using an application called nRF Connect."

Schematics

Code

Real-Time Digital Information Display Using LED Matrix with Wireless Control via BLE and ESP32

#include <MD_Parola.h>
#include <MD_MAX72xx.h>
#include <SPI.h>
#include <BLEDevice.h>
#include <BLEUtils.h>
#include <BLEServer.h>

#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define MAX_DEVICES 4

#define DATA_PIN D6  // DIN
#define CS_PIN   D5  // CS
#define CLK_PIN  D7  // CLK

MD_Parola display = MD_Parola(HARDWARE_TYPE, DATA_PIN, CLK_PIN, CS_PIN, MAX_DEVICES);

BLECharacteristic *pCharacteristic;
bool newText = true;
String receivedText = "UHUY LED READY TO PAIR";

#define SERVICE_UUID        "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
#define CHARACTERISTIC_UUID "beb5483e-36e1-4688-b7f5-ea07361b26a8"

class MyCallbacks : public BLECharacteristicCallbacks {
  void onWrite(BLECharacteristic *pCharacteristic) {
    String newValue = String((char*)pCharacteristic->getData());  // ← SOLUSI FIX
    receivedText = newValue;
    newText = true;
  }
};

void setup() {
  Serial.begin(115200);
  display.begin();
  display.setIntensity(5);
  display.displayClear();

  BLEDevice::init("UHUY LED");
  BLEServer *pServer = BLEDevice::createServer();
  BLEService *pService = pServer->createService(SERVICE_UUID);
  pCharacteristic = pService->createCharacteristic(
                      CHARACTERISTIC_UUID,
                      BLECharacteristic::PROPERTY_WRITE
                    );
  pCharacteristic->setCallbacks(new MyCallbacks());
  pService->start();
  BLEAdvertising *pAdvertising = BLEDevice::getAdvertising();
  pAdvertising->start();

  Serial.println("BLE aktif. Kirim teks dari HP ke matrix.");
}

void loop() {
  if (newText) {
    display.displayClear();
    display.displayScroll(receivedText.c_str(), PA_LEFT, PA_SCROLL_LEFT, 65);
    while (!display.displayAnimate()) delay(10);
    newText = true;
  }
}

LED Matrix Information Board Via Bluetooth