7. Arduino GPIO Practices and Cautions

Question.4

Adam has connected the switch to GPIO 4 as follows. By running which of the following programs on Arduino UNO will damage its GPIO when the switch is pressed?

#define GPIO 4
void setup() {
  pinMode(GPIO, INPUT_PULLUP);
}
void loop() {
  bool readState = digitalRead(GPIO);
}

#define GPIO 4

void setup() {
  pinMode(GPIO, OUTPUT);
}
void loop() {
  digitalWrite(GPIO,LOW);
}

#define GPIO 4

void setup() {
  pinMode(GPIO, OUTPUT);
}
void loop() {
  digitalWrite(GPIO, HIGH);
}

#define GPIO 4

void setup() {
  pinMode(GPIO, INPUT);
}
void loop() {
  bool readState = digitalRead(GPIO);
}