Serial.print and Serial.write(byte[],length) not working properly

Products & Technology XIAO
1

Hello.
I’m trying to communicate between XIAO and PC.
When sending data in multiples of 64 bytes from XIAO, it is not sent immediately,
but is sent together when some other data is sent later.
The code is below:

void setup() {
  Serial.begin(9600);
  while (!Serial);
}
void loop() {
  Serial.println("Start");
  delay(3000);
//  Serial.print("012345678901234567890123456789012345678901234567890123456789012");//OK
  Serial.print("0123456789012345678901234567890123456789012345678901234567890123");//NG
//  Serial.print("01234567890123456789012345678901234567890123456789012345678901234");//OK
  delay(3000);
  Serial.println("\r\nEnd");
}

A similar problem occurs with Serial.write (data [], length).
Does anyone know about this?
Thank you.

2

You can pass flash-memory based strings to Serial.print() by wrapping them with F(). For example:

Serial.print(F("Hello World"))

Can you try the above method!

src: https://www.arduino.cc/reference/en/language/functions/communication/serial/print/