Unit 12: Triggered countdown

 

 

Wiring Image:

 

Schematic:

Code for Sketch One: 

#include 

// Define pins for TM1637 display
const int CLK_PIN = 3;
const int DIO_PIN = 2;

// Define pins for wires
const int WIRE1_PIN = 10, WIRE2_PIN = 11, WIRE3_PIN = 12, WIRE4_PIN = 13;
// Define pin for the buzzer
const int BUZZER_PIN = 8;

// Create display object
GyverTM1637 display(CLK_PIN, DIO_PIN);

// Variables to manage the countdown timer
int timeRemaining = 120; // Countdown time in seconds (2 minutes)
unsigned long previousMillis = 0;
const long interval = 1000; // Interval for countdown (1 second)

// Variable to track if the countdown is running
bool countdownRunning = true;
bool wireCut[4] = {false, false, false, false}; // Track which wires have been cut

void setup() {
  // Initialize the display
  display.clear();
  display.brightness(7);
  updateDisplay();

  // Initialize pins for wires
  pinMode(WIRE1_PIN, INPUT_PULLUP);
  pinMode(WIRE2_PIN, INPUT_PULLUP);
  pinMode(WIRE3_PIN, INPUT_PULLUP);
  pinMode(WIRE4_PIN, INPUT_PULLUP);

  // Initialize pin for the buzzer
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  // Check if the countdown is running
  if (countdownRunning) {
    // Check if it’s time to update the countdown
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval) {
      previousMillis = currentMillis;

      timeRemaining--;
      updateDisplay();

      // If the time runs out, sound the alarm
      if (timeRemaining <= 0) {
        countdownRunning = false;
        soundAlarm();
      }
    }
  }

  // Check the status of the wires
  checkWires();
}

// Function to check the status of the wires
void checkWires() {
  if (digitalRead(WIRE1_PIN) == HIGH && !wireCut[0]) {
    soundAlarm();
    wireCut[0] = true;
  } else if (digitalRead(WIRE2_PIN) == HIGH && !wireCut[1]) {
    timeRemaining -= 10;
    if (timeRemaining < 0) timeRemaining = 0;
    updateDisplay();
    wireCut[1] = true;
  } else if (digitalRead(WIRE3_PIN) == HIGH && !wireCut[2]) {
    timeRemaining -= 10;
    if (timeRemaining < 0) timeRemaining = 0;
    updateDisplay();
    wireCut[2] = true;
  } else if (digitalRead(WIRE4_PIN) == HIGH && !wireCut[3]) {
    timeRemaining -= 10;
    if (timeRemaining < 0) timeRemaining = 0;
    updateDisplay();
    wireCut[3] = true;
  }
}

// Function to update the display
void updateDisplay() {
  int minutes = timeRemaining / 60;
  int seconds = timeRemaining % 60;
  display.display(0, minutes / 10);   // Tens of minutes
  display.display(1, minutes % 10);   // Ones of minutes
  display.display(2, seconds / 10);   // Tens of seconds
  display.display(3, seconds % 10);   // Ones of seconds
  display.point(1);                   // Display the colon
}

// Function to sound the alarm
void soundAlarm() {
  digitalWrite(BUZZER_PIN, HIGH);
  delay(3000); // Sound the alarm for 3 seconds
  digitalWrite(BUZZER_PIN, LOW);
}

    

 

Code for Sketch Two: 

#include 

// Define pins for the display, wires and buzzer
const int WIRE1_PIN = 10, WIRE2_PIN = 11, WIRE3_PIN = 12, WIRE4_PIN = 13, BUZZER_PIN = 8, CLK_PIN = 3, DIO_PIN = 2;

// Create display object
GyverTM1637 display(CLK_PIN, DIO_PIN);

int timeRemaining = 120; // Countdown time in seconds (2 minutes)
unsigned long previousMillis = 0;
const long interval = 1000; // Interval for countdown (1 second)

bool countdownRunning = true;
bool wireCut[4] = {false, false, false, false};

// Random safe wire variable
int safeWire;

void setup() {
  // Initialize random seed
  randomSeed(analogRead(0));

  // Select a random safe wire
  safeWire = random(1, 5); // Random number between 1 and 4

  // Initialize the display
  display.clear();
  display.brightness(7);
  updateDisplay();

  // Initialize pins for wires
  pinMode(WIRE1_PIN, INPUT_PULLUP);
  pinMode(WIRE2_PIN, INPUT_PULLUP);
  pinMode(WIRE3_PIN, INPUT_PULLUP);
  pinMode(WIRE4_PIN, INPUT_PULLUP);

  // Initialize pin for the buzzer
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  if (countdownRunning) {
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval) {
      previousMillis = currentMillis;

      timeRemaining--;
      updateDisplay();

      // If the time runs out, sound the alarm
      if (timeRemaining <= 0) {
        countdownRunning = false;
        soundAlarm();
      }
    }
  }

  checkWires();
}

void checkWires() {
  if (digitalRead(WIRE1_PIN) == HIGH && !wireCut[0]) {
    if (safeWire == 1) {
      countdownRunning = false;
    } else {
      timeRemaining -= 10;
      if (timeRemaining < 0) timeRemaining = 0;
    }
    updateDisplay();
    wireCut[0] = true;
  } else if (digitalRead(WIRE2_PIN) == HIGH && !wireCut[1]) {
    if (safeWire == 2) {
      countdownRunning = false;
    } else {
      timeRemaining -= 10;
      if (timeRemaining < 0) timeRemaining = 0;
    }
    updateDisplay();
    wireCut[1] = true;
  } else if (digitalRead(WIRE3_PIN) == HIGH && !wireCut[2]) {
    if (safeWire == 3) {
      countdownRunning = false;
    } else {
      timeRemaining -= 10;
      if (timeRemaining < 0) timeRemaining = 0;
    }
    updateDisplay();
    wireCut[2] = true;
  } else if (digitalRead(WIRE4_PIN) == HIGH && !wireCut[3]) {
    if (safeWire == 4) {
      countdownRunning = false;
    } else {
      timeRemaining -= 10;
      if (timeRemaining < 0) timeRemaining = 0;
    }
    updateDisplay();
    wireCut[3] = true;
  }
}

void updateDisplay() {
  int minutes = timeRemaining / 60;
  int seconds = timeRemaining % 60;
  display.display(0, minutes / 10);   // Tens of minutes
  display.display(1, minutes % 10);   // Ones of minutes
  display.display(2, seconds / 10);   // Tens of seconds
  display.display(3, seconds % 10);   // Ones of seconds
  display.point(1);                   // Display the colon
}

// Function to sound the alarm
void soundAlarm() {
  digitalWrite(BUZZER_PIN, HIGH);
  delay(3000); // Sound the alarm for 3 seconds
  digitalWrite(BUZZER_PIN, LOW);
}

    

 

Notes: 

Use the display library by writing: #include <gyvertm1637.h> at the top of the sketch. This page treats it as instruction, so will not let us show it in the main code itself.