Arduino Hand Gesture Smart Watch

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The SmartTime Watch is an Arduino-based smartwatch that displays the current date and time on an OLED screen when you bring your hand near an IR sensor. Using a Real-Time Clock (RTC) module, the watch accurately shows the date and time for 3 seconds, after which the display goes into an idle state, turning off the screen for a more energy-efficient design.

Components needed:

  1. Arduino board (e.g., Arduino Uno, Nano, or any compatible board)
  2. OLED display (I2C, 128×64 pixels, for time display)
  3. IR sensor (to detect when you bring your hand near)
  4. RTC module (like DS3231 or DS1307 to keep track of time)

Libraries required:

  • Wire: For communication with the I2C devices (like OLED and RTC)
  • Adafruit_SSD1306: For controlling the OLED display
  • RTClib: For RTC communication

Wiring:

  1. OLED Display:
    • VCC to 5V
    • GND to GND
    • SCL to A5 (for Arduino Uno)
    • SDA to A4 (for Arduino Uno)
  2. IR Sensor:
    • VCC to 5V
    • GND to GND
    • OUT to a digital pin (let’s assume pin 2)
  3. RTC Module (DS3231):
    • VCC to 5V
    • GND to GND
    • SCL to A5 (same as OLED)
    • SDA to A4 (same as OLED)

Code:

#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <RTClib.h>

// OLED display settings
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1  // Reset pin not used with I2C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// IR sensor pin
const int irPin = 2;

// RTC instance
RTC_DS3231 rtc;

unsigned long displayStartTime = 0; // To track when to switch from date and time to idle
const unsigned long displayDuration = 5000; // 5 seconds for date and time display
bool handDetected = false;  // To track if hand is detected near the IR sensor

void setup() {
  // Start serial communication
  Serial.begin(9600);

  // Initialize the OLED display
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {  // Use 0x3C for most displays
    Serial.println(F("OLED initialization failed"));
    while (true);
  }
  display.display();
  delay(2000); // Wait for a while

  // Initialize the RTC
  if (!rtc.begin()) {
    Serial.println(F("Couldn't find RTC"));
    while (true);
  }

  // Set the time automatically from the computer (if needed)
  // Uncomment to set time once (use it once and then comment out)
  rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));

  // Set IR sensor pin mode
  pinMode(irPin, INPUT);

  // Initially clear the display
  display.clearDisplay();
}

void loop() {
  // Check if hand is near the IR sensor
  if (digitalRead(irPin) == HIGH) {  // IR sensor detects hand (HIGH)
    if (!handDetected) {
      handDetected = true; // Mark hand as detected
      displayStartTime = millis();  // Start the timer when hand is detected
    }

    unsigned long elapsedTime = millis() - displayStartTime;

    // Show the date and time for 3 seconds
    if (elapsedTime < displayDuration) {
      DateTime now = rtc.now();
      display.clearDisplay();
      display.setTextSize(1);  // Smaller text for date
      display.setTextColor(SSD1306_WHITE);
      display.setCursor(0, 0);  // Set starting position for date
      display.print(now.day(), DEC);
      display.print('/');
      display.print(now.month(), DEC);
      display.print('/');
      display.print(now.year(), DEC);

      display.setTextSize(2);  // Larger text for time
      display.setCursor(0, 20);  // Set position for time
      display.print(now.hour(), DEC);
      display.print(':');
      if (now.minute() < 10) display.print('0');
      display.print(now.minute(), DEC);
      display.print(':');
      if (now.second() < 10) display.print('0');
      display.print(now.second(), DEC);
      
      display.display();
    } else {
      // After 3 seconds, go idle (clear the screen)
      display.clearDisplay();
      display.display();
    }

  } else {
    // When hand is away, reset the hand detection and clear the screen
    if (handDetected) {
      handDetected = false; // Mark hand as not detected
      display.clearDisplay(); // Clear the screen when hand is no longer detected
      display.display();
    }
  }
}
  1. Libraries:
    • Wire.h allows I2C communication between the Arduino and the OLED/RTC.
    • Adafruit_SSD1306.h is used to interact with the OLED display.
    • RTClib.h helps with the RTC (Real-Time Clock) module.
  2. Initialization:
    • The setup() function initializes the OLED, RTC, and IR sensor pin.
    • The time is set from the computer’s date and time when rtc.adjust() is uncommented and used once to set the initial time.
  3. Main logic:
    • In the loop() function, the IR sensor is constantly monitored. When the sensor detects your hand (i.e., digitalRead(irPin) == HIGH), the time from the RTC module is fetched and displayed on the OLED screen.

How to Set Time:

  • If you’re uploading the code for the first time and want to set the RTC from your computer’s current date and time, uncomment the line rtc.adjust(DateTime(F(__DATE__), F(__TIME__))); in the setup() function, and upload the code.
  • After the initial setup, comment out this line again to keep the time from the RTC running.