Arduino Keypad Countdown Timer with Rainbow Alarm & Tilt Shutoff

1#include <Adafruit_NeoPixel.h>
2#include <Keypad.h>
3#include <Adafruit_LEDBackpack.h>
4
5const byte ROWS = 4;
6const byte COLS = 3;
7const int LED = 4;
8const int NUM_PIXELS = 24;
9const char KEYMAP[ROWS][COLS] =
10{
11  {'1', '2', '3'},
12  {'4', '5', '6'},
13  {'7', '8', '9'},
14  {'*', '0', '#'},
15};
16
17String input = ""; 
18const int TILT = A0;
19int isTilt = 0;
20
21byte ROW_PINS[ROWS] = {13, 12, 11, 10};
22byte COL_PINS[COLS] = {9, 8, 7}; 
23
24Keypad keypad = Keypad(makeKeymap(KEYMAP), ROW_PINS, COL_PINS, ROWS, COLS);
25Adafruit_7segment display = Adafruit_7segment();
26Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUM_PIXELS, LED, NEO_GRB + NEO_KHZ800);
27
28// Timer Variables
29long totalSeconds = 0;       
30bool timerRunning = false;   
31unsigned long lastTick = 0;  
32
33// Alarm State Variables
34bool alarmActive = false;    // Tracks if the alarm is currently going off
35const int SPEAKER = 6;   
36
37void setup()
38{
39  pinMode(TILT, INPUT);
40  pinMode(SPEAKER, OUTPUT);
41  Serial.begin(9600);
42  display.begin(); 
43  updateDisplay(0);   
44  pixels.begin();
45  pixels.setBrightness(150);
46  pixels.show();
47}
48
49void loop()
50{
51  char key = keypad.getKey();
52
53  // Read the tilt sensor state continuously
54  if (analogRead(TILT) == 1013) {
55    isTilt = 0;
56  } else {
57    isTilt = 1;
58  }
59
60  // --- TILT SENSOR ALARM TURN OFF ---
61  // If the alarm is currently blasting and the tilt sensor is triggered (isTilt == 1), shut everything down and reset.
62  if (alarmActive && isTilt == 1) {
63    resetTimer();
64    alarmActive = false;
65    noTone(SPEAKER); // Stop the sound
66    clearPixels();
67    Serial.println("Alarm turned off via Tilt Sensor!");
68  }
69
70  if (key != NO_KEY) {
71    tone(SPEAKER, 350, 40);
72    // CASE 1: Numeric input (Only if timer/alarm isn't active)
73    if (key >= '0' && key <= '9' && !timerRunning && !alarmActive && input.length() < 4) {
74      input += key;
75      updateDisplay(input.toInt());
76    }
77    
78    // CASE 2: '#' Starts the countdown
79    else if (key == '#' && !timerRunning && !alarmActive && input.length() > 0) {
80      int targetTime = input.toInt();
81      int minutes = targetTime / 100;
82      int seconds = targetTime % 100;
83      
84      totalSeconds = (minutes * 60) + seconds;
85      
86      if (totalSeconds > 0) {
87        timerRunning = true;
88        lastTick = millis(); 
89        Serial.println("Timer Started!");
90      }
91    }
92    
93    // CASE 3: '*' Resets everything
94    else if (key == '*') {
95      resetTimer();
96      alarmActive = false;
97      noTone(SPEAKER);
98      clearPixels();
99      Serial.println("Timer Reset.");
100    }
101  }
102
103  // TIMER TICK LOGIC
104  if (timerRunning) {
105    if (millis() - lastTick >= 1000) {
106      lastTick += 1000; 
107      totalSeconds--;   
108      
109      int displayMinutes = totalSeconds / 60;
110      int displaySeconds = totalSeconds % 60;
111      int displayTime = (displayMinutes * 100) + displaySeconds;
112      
113      updateDisplay(displayTime);
114      
115      // Check if time is up
116      if (totalSeconds <= 0) {
117        timerRunning = false;
118        alarmActive = true; // Trigger the alarm state!
119        Serial.println("TIME IS UP! Alarm Active. Tilt device to stop.");
120      }
121    }
122  }
123
124  // ALARM BEHAVIOR LOGIC
125  // If the alarm is active, run alert loop
126  if (alarmActive) {
127    // Flash the display "0000" on and off every 250ms using millis
128    if ((millis() / 250) % 2 == 0) {
129      display.clear();
130      display.writeDisplay();
131      noTone(SPEAKER);
132    } else {
133      updateDisplay(0);
134      tone(SPEAKER, 1000);
135    }
136    long firstPixelHue = (millis() * 250); // Multiply to adjust the spinning speed (higher = faster)
137    
138    for (int i = 0; i < NUM_PIXELS; i++) {
139      // Calculate a unique hue value for each pixel around the 24-LED ring
140      int pixelHue = firstPixelHue + (i * 65536L / NUM_PIXELS);
141      pixels.setPixelColor(i, pixels.gamma32(pixels.ColorHSV(pixelHue)));
142    }
143    pixels.show(); 
144  }
145}
146
147void updateDisplay(int value) {
148  display.print(value, DEC);
149  if (timerRunning) {
150    display.drawColon(true);
151  } else {
152    display.drawColon(false);
153  }
154  display.writeDisplay();
155}
156
157void resetTimer() {
158  timerRunning = false;
159  input = "";
160  totalSeconds = 0;
161  updateDisplay(0);
162}
163
164void clearPixels() {
165  for (int i = 0; i < NUM_PIXELS; i++) {
166    pixels.setPixelColor(i, pixels.Color(0, 0, 0));
167  }
168  pixels.show();
169}