WiFi-Synced Alarm Robot

#include <Arduino.h>
#include <WiFi.h>
#include <time.h>

// Enter your own Wi-Fi details before deploying.

// Forward declarations
void stopRobot();
void moveForward();
void spinRight();
bool stopButtonPressed();
void startWiFiIfNeeded();
void updateMotion();

const char *WIFI_SSID = "YOUR_WIFI_SSID";
const char *WIFI_PASSWORD = "YOUR_WIFI_PASSWORD";

// Set this to your UTC offset in seconds. Example: India (IST) is 19800.
const long GMT_OFFSET_SECONDS = 19800;
const int DAYLIGHT_OFFSET_SECONDS = 0;
const char *NTP_SERVER = "pool.ntp.org";

const int MOTOR_A_IN1 = 16;
const int MOTOR_A_IN2 = 17;
const int MOTOR_B_IN3 = 18;
const int MOTOR_B_IN4 = 19;
const int STOP_BUTTON_PIN = 21;

const int TARGET_HOUR = 7;
const int TARGET_MINUTE = 0;
const unsigned long FORWARD_MS = 800;
const unsigned long TURN_MS = 400;
const unsigned long WIFI_RETRY_MS = 10000;
const unsigned long BUTTON_DEBOUNCE_MS = 35;

bool alarmActive = false;
int silencedYearDay = -1;
bool movingForward = true;
unsigned long motionStartedAt = 0;
bool lastButtonReading = HIGH;
bool stableButtonState = HIGH;
unsigned long lastButtonChangeAt = 0;
unsigned long lastWiFiAttemptAt = 0;

void stopRobot() {
  digitalWrite(MOTOR_A_IN1, LOW);
  digitalWrite(MOTOR_A_IN2, LOW);
  digitalWrite(MOTOR_B_IN3, LOW);
  digitalWrite(MOTOR_B_IN4, LOW);
}

void moveForward() {
  digitalWrite(MOTOR_A_IN1, HIGH);
  digitalWrite(MOTOR_A_IN2, LOW);
  digitalWrite(MOTOR_B_IN3, HIGH);
  digitalWrite(MOTOR_B_IN4, LOW);
}

void spinRight() {
  digitalWrite(MOTOR_A_IN1, HIGH);
  digitalWrite(MOTOR_A_IN2, LOW);
  digitalWrite(MOTOR_B_IN3, LOW);
  digitalWrite(MOTOR_B_IN4, HIGH);
}

bool stopButtonPressed() {
  const bool reading = digitalRead(STOP_BUTTON_PIN);
  const unsigned long now = millis();

  if (reading != lastButtonReading) {
    lastButtonChangeAt = now;
    lastButtonReading = reading;
  }

  if (now - lastButtonChangeAt >= BUTTON_DEBOUNCE_MS && reading != stableButtonState) {
    stableButtonState = reading;
    return stableButtonState == LOW;
  }
  return false;
}

void startWiFiIfNeeded() {
  if (WiFi.status() == WL_CONNECTED || (lastWiFiAttemptAt != 0 && millis() - lastWiFiAttemptAt < WIFI_RETRY_MS)) {
    return;
  }

  lastWiFiAttemptAt = millis();
  Serial.printf("Connecting to %s\n", WIFI_SSID);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
}

void updateMotion() {
  const unsigned long now = millis();
  const unsigned long phaseLength = movingForward ? FORWARD_MS : TURN_MS;

  if (now - motionStartedAt < phaseLength) {
    return;
  }

  movingForward = !movingForward;
  motionStartedAt = now;
  if (movingForward) {
    moveForward();
  } else {
    spinRight();
  }
}

void setup() {
  Serial.begin(115200);

  pinMode(MOTOR_A_IN1, OUTPUT);
  pinMode(MOTOR_A_IN2, OUTPUT);
  pinMode(MOTOR_B_IN3, OUTPUT);
  pinMode(MOTOR_B_IN4, OUTPUT);
  pinMode(STOP_BUTTON_PIN, INPUT_PULLUP);
  stopRobot();

  WiFi.mode(WIFI_STA);
  startWiFiIfNeeded();
  configTime(GMT_OFFSET_SECONDS, DAYLIGHT_OFFSET_SECONDS, NTP_SERVER);
}

void loop() {
  startWiFiIfNeeded();

  struct tm now;
  const bool timeValid = getLocalTime(&now, 10);
  if (!timeValid) {
    stopRobot();
    alarmActive = false;
    delay(10);
    return;
  }

  const bool scheduledMinute = now.tm_hour == TARGET_HOUR && now.tm_min == TARGET_MINUTE;
  const bool wasSilencedToday = silencedYearDay == now.tm_yday;

  if (scheduledMinute && !wasSilencedToday && !alarmActive) {
    alarmActive = true;
    movingForward = true;
    motionStartedAt = millis();
    moveForward();
    Serial.println("Alarm active: robot is moving.");
  }

  if (alarmActive) {
    if (stopButtonPressed()) {
      alarmActive = false;
      silencedYearDay = now.tm_yday;
      stopRobot();
      Serial.println("Alarm silenced until tomorrow.");
    } else {
      updateMotion();
    }
  } else {
    stopRobot();
  }

  delay(10);
}