Strange output when passing data through two Arduinos

Projects Programming
1

Hello,

I am currently working on a project on Tinkercad, in particular, I'm trying to send data from one to the other. I have connected the two as you see in the screenshot down below:
immagine

The first Arduino (the one on the top) has the following code:


#include <LiquidCrystal.h>
#include <SoftwareSerial.h>

SoftwareSerial mySerial(9, 8);

const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);

void setup()
{
  lcd.begin(16, 2);
  lcd.print("Hello world");
  
  Serial.begin(9600);
  mySerial.begin(9600);
}

void loop()
{
  lcd.setCursor(0, 1);
  lcd.print(millis() / 1000);
  
  mySerial.println("Hello from Arduino A");
  delay(50000);
}

While the second one (the one on the bottom left), has the following code:

#include <Keypad.h>
#include <SoftwareSerial.h>

SoftwareSerial mySerial(13, 12);
  
const byte COLS = 4;
const byte ROWS = 4;

char hexaKeys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'},
};

byte rowPins[ROWS] = {9, 8, 7, 6}; 
byte colPins[COLS] = {5, 4, 3, 2}; 

Keypad customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS); 

String password = "A196*", input = "";
char customKey;

void setup()
{
  Serial.begin(9600);
  mySerial.begin(9600);
}

void loop() {
  char customKey = customKeypad.getKey();
  if (customKey) {
    input += customKey;
    Serial.println(input);
  }
  
  if (mySerial.available()) { // Controlla se ci sono dati disponibili
    String message = mySerial.readStringUntil('\n'); // Leggi i dati ricevuti fino a un newline
    Serial.println("Received message: " + message); // Stampa i dati ricevuti sulla seriale del computer
  }
}

Everything works fine, in fact when I run the code I receive in the second Arduino some text, but the problem is that it's not what the first one sent:
Message: Hello from Arduino A
I receive: Received message: ¤²‹ë2ɽµA V_åý

I really hope you can help me.
Thank you very much in advice

2

Why do you have Rx and Tx (pins 0 and 1) of both Arduinos connected to each other? Those pins are also used for communication with the PC.

3

Put a /0 terminator on the end of the above string.

4

@xfpd , why would /0 help?

5

It is called process of elimination. Ruling out possibilities.

Sending the end of text character would validate or invalidate the transmitter as the problem.

6

I've tried with this

mySerial.println("Hello from Arduino A/0");

But I still got
Received message: ¤²¶ë 2ɽµA VWåý

7

I've used .write for the Serial transmission. Now it works