Microbit V2 delay slows down when using Visual Studio Code

[rouderaa42]

Hi,
A strange phenomenon I am encountering with using the microbit V2 with Visual Studio Code using debug. It seems that the delay() function becomes very slow after a few seconds. The following demo program runs a blinking led for about 3 seconds with the expected delay of 1000 ms but gets down to about a delay of 60 seconds per blink after that. Somehow this has to do with using Visual Studio Code because if I run the same code without Visual Studio Code then the same code with the delay does not slow down. The led blinks at a rate of 1 second as expected then.
Any ideas what might be causing this behavior ?

Kind regards,
Rob van der Ouderaa

#include <Arduino.h>

#define ROW 25
#define COL 3

void setup() {
  pinMode(ROW, OUTPUT);
  digitalWrite(ROW, HIGH);
  pinMode(COL, OUTPUT);
  digitalWrite(COL, LOW);
}

void loop() {
  digitalWrite(COL, LOW);
  delay(1000);                       // wait for a second
  digitalWrite(COL, HIGH);
  delay(1000);                       // wait for a second
}

[killzone_kid]

@rouderaa42

with using Visual Studio Code

What does this mean?

[rouderaa42]

It means that I start the microbit program from the Visual Studio Code IDE (https://code.visualstudio.com/). It allows me to debug the code running on the microbit. I can do things like single step through the source code and halt and examine the program that is running on the microbit.

[killzone_kid]

So you are not using Arduino IDE? Is micro bit even Arduino compatible? Haven’t seen c++ usage from quick search just python and some handicapped visual thingy

[rouderaa42]

Sure, the microbit V2 is designed to be Arduino programmable. But Arduino basically is just C++ with additional libraries and a very thin layer calling setup() and loop(). By using the Visual Studio Ide and including <Arduino.h> you can just program it like in the Arduino IDE but with the benefits of a better editor and real-time debugger. Cool stuff :-).