ESP32 Dev Mod in Arduino IDE

Using Arduino Programming Questions
1

What the hell?????

I see YYYYYYYY in serial monitor.
But I never see XXXXXXX.
void setup() must be called otherwise I would never see YYYYYYYY.
But why is XXXXXXX never output????

void setup() 
{
  Serial.begin(115200);
  while (!Serial);

  Serial.println(F("XXXXXXX"));
}

void loop() 
{
  Serial.println(F("YYYYYYYY"));
  delay(1000);
}
2

try adding a short delay to give Serial time to start, e.g.

void setup() 
{
  Serial.begin(115200);
  while (!Serial);
  delay(1000);
  Serial.println(F("XXXXXXX"));

on an ESP32 serial monitor displays

XXXXXXX
YYYYYYYY
YYYYYYYY
YYYYYYYY
YYYYYYYY
YYYYYYYY
YYYYYYYY
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3

Have you checked that !Serial actually pauses, add a small delay before the XXX. Note the timestamp, subtract the delay and that is how long the Serial port took to initialize.

4

It won't. The !Serial construct is only useful if used on a processor with native USB port, not a UART-based port as on an ESP32 Dev Board.

Yes.

3 Likes