CLUE Serial seems not to work correctly Moderators: adafruit_support_bill, adafruit

[johnsondavies]

Printing to the serial port on CLUE holds up the output for some reason. Here's a program to demonstrate:

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void setup() {
  Serial.begin(9600);
  while ( !Serial ) delay(10);
  Serial.println("Goodnight moon!");
  for (int i=0; i<10; i++) {
    Serial.println("Wait...");
  }
  delay(5000);
  Serial.println("Hello sun!");
}

void loop() {}

Running this from the Arduino IDE, and then opening the Serial Monitor, should display "Goodnight moon!" and "Wait..." etc, followed by "Hello sun!" after five seconds.

On the CLUE it displays nothing for five seconds, and then displays all the text. It also gives the incorrect result on the Adafruit ItsyBitsy nRF52840.

On all other boards I've tried, such as Grand Central M4, it works correctly.

It's a problem because it makes my Lisp interpreter, uLisp, unusable on these nRF52840 boards.

I'm using Adafruit nRF52 boards file 0.19.0. on Arduino IDE 1.8.9 on a Mac Powerbook.

[kevinjwalters]

If you stick a counter inside the while loop how many times is that running on the nRF52840 boards?

[johnsondavies]

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void setup() {
  Serial.begin(9600);
  int n = 0;
  while ( !Serial ) { n++; delay(10); }
  Serial.println(n);
}

prints 664.

[kevinjwalters]

So all the output does appear, it just appears in one lump?

For experimentation purposes, you could add a Serial.flush() after each println to see what it does.

[johnsondavies]

So all the output does appear, it just appears in one lump?

Yes, after five seconds.