You now have all the know-how to build our safety box!
Let's start with the code:
//Initializing a variable to store the value of the button state
int lidState = 0;
int keyState = 0;
int lidPin = 2;
int keyPin = 3;
int alarmPin = 9;
// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital I/O pins
pinMode(lidPin, INPUT);
pinMode(keyPin, INPUT);
pinMode(alarmPin, OUTPUT);
}
// the loop function runs over and over again forever
void loop() {
lidState = digitalRead(lidPin);
if ( lidState == LOW )
{
keyState = digitalRead(keyPin);
if ( keyState == HIGH )
digitalWrite(alarmPin, LOW);
else
digitalWrite(alarmPin, HIGH);
}
else
digitalWrite(alarmPin, LOW);
}
We start by storing the pin numbers in variables...