byte rowPins[] = { 2,  3};
byte colPins[] = {14, 15};
//-----------------------------------------------------------------
void setup() {
  Serial.begin(115200);
  for (int i = 0; i < 2; i++) {
    pinMode(rowPins[i], OUTPUT);
    pinMode(colPins[i], INPUT_PULLUP);
  }
}
//-----------------------------------------------------------------
void loop() {
  for (int i = 0; i < 2; i++) {
    digitalWrite(rowPins[i], LOW);
    Serial.print("rowPin  ");
    Serial.print(rowPins[i]);
    Serial.print(" ");
    Serial.print(digitalRead(rowPins[i]));
   Serial.print("  colPins  ");
    for (int j = 0; j < 2; j++) {
      
      Serial.print(colPins[j]);
      Serial.print(" ");
      Serial.print(digitalRead(colPins[j]));
       Serial.print(" ");
       delay(100);
    }
    digitalWrite(rowPins[i], HIGH);
    Serial.println(" ");
  }
  Serial.println(" ");
  delay(300);
}