"Hello World! " program results in stutter.

Hi all, I'm starting at the very beginning with the "Hello World!" program on my Uno, but when I transfer to the Serial Monitor it shows an extra "Hell", ie: "HellHello World!" I know I'm a bit ham-fisted, but I didn't expect swearing!

void setup() {
  Serial.begin (9600);
  Serial.println ("Hello World!");
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

I tried changing line 3 to:- Serial.println (F("Hello World!")); but still the same stutter

I'm running Arduino 1.6.13 64bit in LinuxLite 3.2 64bit on a Toshiba notebook.

Any help would be greatly appreciated. Dave.

After the Serial.begin() call, try adding a small delay (10 milliseconds, maybe) before printing.

DaveC1940: it shows an extra "Hell", ie: "HellHello World!"

The first few characters are produced when the Arduino starts. Then when you open the Serial Monitor it restarts the Arduino and starts sending again.

Just ignore the first few characters. Maybe start your program by sending couple do Serial.println() to move on the a new line.

If you were receiving the Arduino output in a PC program that you wrote yourself you would code it to ignore those characters.

...R

Thanks guys, that's given me a couple of things to play with and a guide to how to look at problems. Regards, Dave.

DaveC1940:
Hi all, I’m starting at the very beginning with the “Hello World!” program on my Uno, but when I transfer to the Serial Monitor it shows an extra “Hell”, ie: “HellHello World!” I know I’m a bit ham-fisted, but I didn’t expect swearing!
Any help would be greatly appreciated. Dave.

Maybe your program starts twice in very short time aused by an automatic reset (opening the serial monitor) after a few milliseconds.

So better start output with a Serial.println() at the beginning, then following the “real” output. Perhaps

void setup() {
  Serial.begin (9600);
Serial.println();
  Serial.println ("Hello World!");

}

BTW: Which board is it? Is it an “Arduino LEONARDO” or “Arduino Micro”, perhaps?