Oszilloskop am Calliope

// Connect P1 with Channel 1 X and P2 with Channel 2 Y of your Oscilloscope
void setup() {  
  pinMode(1, OUTPUT);
  pinMode(2, OUTPUT);
}

void loop(){
  digitalWrite(1, HIGH);
  digitalWrite(2, HIGH);
  digitalWrite(1, LOW);
  digitalWrite(2, LOW);

}