Solved - DFRobot W5500 sketch doesn't startwith ext.supply?

Using Arduino Microcontrollers
1

Hi,
I do not what is going on. I use DFRobot Ethernet W5500 board and when I create wery simple sketch like this:

void setup() {
  pinMode(13, OUTPUT);
   while(!Serial);
  Serial.begin(9600);
  Serial.println(F("TEST"));
  
}
void loop() {
  digitalWrite(13, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                   // wait for a second
  digitalWrite(13, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                  // wait for a second
}

it doesn't start when I'm powering the board with an external power supply? To be honest program start when I start "Serial monitor".
Problem doesn't appear when I comment everything related with serial port.

Do you know how to mitigate this problem?

Regards
Michał

2

I've solved a problem, line
while(!Serial);
should be removed. In documentation we read "if(Serial) This will only return false if querying the Leonardo's USB CDC serial connection before it is ready."

3

So is your problem solved, or not? If so, modify the subject line of your first post here to add "(Solved)". (Do not remove any other part of it.)