Displaying text on dot matrix through Blynk app using Arduino platform (Maker UNO + ESP WiFi Shield).

ESP8266Blynk.ino

/* Comment this out to disable prints and save space */
//#define BLYNK_PRINT Serial

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "BlynkAuthToken";

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "YourWiFiSSID";
char pass[] = "YourWiFiPass";

BLYNK_WRITE(V0)
{
  String textIn = param.asStr();
  Serial.print(textIn + "\n");
}

void setup()
{
  // Debug console
  Serial.begin(9600);

  Blynk.begin(auth, ssid, pass);

  delay(5000);
  Serial.print("Blynk Ready\n");
}

void loop()
{
  Blynk.run();
}

MakerUNOBlynkDotMatrix.ino

#include <MD_Parola.h>
#include <MD_MAX72xx.h>
#include <SPI.h>
#include <SoftwareSerial.h>

SoftwareSerial blynkSerial(2, 3);

// Define the number of devices we have in the chain and the hardware interface
// NOTE: These pin numbers will probably not work with your hardware and may
// need to be adapted
#define HARDWARE_TYPE MD_MAX72XX::FC16_HW
#define MAX_DEVICES 4
#define CLK_PIN   13
#define DATA_PIN  11
#define CS_PIN    10

#define NOTE_G4 392
#define NOTE_B4 494
#define BUZZER  8

int melody[] = {NOTE_B4, NOTE_G4};
int noteDurations[] = {8, 8};

// HARDWARE SPI
MD_Parola P = MD_Parola(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);

// Scrolling parameters
uint8_t scrollSpeed = 25;    // default frame delay value
textEffect_t scrollEffect = PA_SCROLL_LEFT;
textPosition_t scrollAlign = PA_LEFT;
uint16_t scrollPause = 2000; // in milliseconds

// Global message buffers shared by Serial and Scrolling functions
#define  BUF_SIZE  75
char curMessage[BUF_SIZE] = { "" };
char newMessage[BUF_SIZE] = { "Cytron Technologies" };
bool newMessageAvailable = true;

void readSerial(void)
{
  static char *cp = newMessage;

  while (blynkSerial.available()) {
    *cp = (char)blynkSerial.read();
    if ((*cp == '\n') || (cp - newMessage >= BUF_SIZE - 2)) { // end of message character or full buffer
      *cp = '\0'; // end the string
      // restart the index for next filling spree and flag we have a message waiting
      cp = newMessage;
      newMessageAvailable = true;
    }
    else  // move char pointer to next position
      cp++;
  }
}

void setup()
{
  Serial.begin(9600);
  Serial.print("\n[Parola Scrolling Display]\nType a message for the scrolling display\nEnd message line with a newline");

  blynkSerial.begin(9600);

  P.begin();
  P.displayText(curMessage, scrollAlign, scrollSpeed, scrollPause, scrollEffect, scrollEffect);
}

void loop()
{
  if (P.displayAnimate()) {
    if (newMessageAvailable) {
      beep();
      strcpy(curMessage, newMessage);
      newMessageAvailable = false;
    }
    P.displayReset();
  }
  readSerial();
}

void beep()
{
  for (int thisNote = 0; thisNote < 2; thisNote++) {
    int noteDuration = 1000 / noteDurations[thisNote];
    tone(BUZZER, melody[thisNote], noteDuration);
    int pauseBetweenNotes = noteDuration * 1.30;
    delay(pauseBetweenNotes);
    noTone(BUZZER);
  }
}