first commit, functional code

README.md

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+Allarme armadio aulastud
+l'obiettivo è fare da dissuasore, non ci sono password, o segnalazioni automatiche. solo avviso acustico con sirena.
+- attiny45
+- un rele
+- pulsante tattile per comando
+- led per informazione stato (abilitato o meno l'allarme)
+- microswitch nello sportello per accorgersi dell'apertura
+- l'allarme si abilita di default alla connessione
+- suona brevemente 2 volte per segnare abilitazione, 1 volta per disabilitazione
+- in caso scatti, suonerà a volume massimo per 10s, poi si disabiliterà fino a riavvio/nuovo comando

allarme_aula_stud.ino

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+#define relayPin 1 // enable/disable relay powering the siren
+#define switchPin 2 // tampering switch sensor
+#define buttonPin 3 // button to be held down to enable/disable alarm
+#define ledPin 4 // status LED to show when alarm is enabled
+#define ringTime 20 // time to ring the siren for (in seconds)
+int enableStatus = 1; // variable to store alarm status (1 = enabled); enabled at boot
+int countDown = 2; // times to repeat siren blip sound in sound() function
+
+void setup() {
+  // here we assign pins as in/out and pull-up the inputs
+  pinMode(relayPin, OUTPUT);
+  digitalWrite(relayPin, LOW);
+  pinMode(switchPin, INPUT_PULLUP);
+  digitalWrite(switchPin, HIGH);
+  pinMode(buttonPin, INPUT_PULLUP);
+  digitalWrite(buttonPin, HIGH);
+  pinMode(ledPin, OUTPUT);
+  digitalWrite(ledPin, LOW);
+  sound(); // give audible feedback at boot
+  delay(10000); // wait 10s, then exit setup
+  
+}
+
+void loop() {
+  
+  LED();
+  
+  ButtonCtrl();
+
+
+ //Main alarm logic follows
+  if (enableStatus == 1 && (digitalRead(switchPin) == LOW)){
+    delay(500); //switch debounce
+    if (digitalRead(switchPin) == LOW){
+      digitalWrite(relayPin, HIGH); //sound the siren!
+      delay(ringTime*1000); //let the siren sound for the duration of defined ringTime
+      digitalWrite(relayPin, LOW); //now switch off the siren
+      digitalWrite(ledPin, LOW);  //switch off status LED
+      enableStatus = 0; //disable the alarm after sounding
+    }
+  }
+}
+
+void sound() {
+  // sound alert function used at boot and alarm enabling
+  if (enableStatus == 1) {
+    while (countDown > 0) {
+      digitalWrite(relayPin, HIGH); //sound the siren!
+      delay(5);
+      digitalWrite(relayPin, LOW); //stop the siren
+      delay(500);
+      countDown--;
+    }
+  }
+}
+
+void LED() {
+  // status LED control logic
+  if (enableStatus == 1) {
+    digitalWrite(ledPin, HIGH); //turn on status LED
+  }
+  else {
+    digitalWrite(ledPin, LOW); //turn off status LED
+  }
+}
+
+void ButtonCtrl() {
+  // check if button is pressed, switch state accordingly
+  if ((digitalRead(buttonPin) == LOW) && enableStatus != 1){
+    delay(500); //button debounce
+    if (digitalRead(buttonPin) == LOW){
+      enableStatus = 1;
+      countDown = 2;
+      sound();
+    }
+  }
+  else if ((digitalRead(buttonPin) == LOW) && enableStatus != 0){
+    delay(500); //button debounce
+    if (digitalRead(buttonPin) == LOW){
+      countDown = 1;
+      sound();
+      enableStatus = 0;
+    }
+  }
+}