Smart Light | Room Simulator

Presence‑activated RGB light using an ESP32, an HC‑SR04 ultrasonic sensor, and a KY‑016 RGB LED. The light toggles when someone is detected close to the sensor and can also be controlled via a simple web page.

What it does

• Measures distance with HC‑SR04; when an object is detected closer than ~8 cm, the light toggles on/off (with a 2 s debounce).
• Serves a minimal web UI to turn the light ON/OFF over Wi‑Fi.
• RGB “on” color is purple (R=128, G=0, B=255); “off” is all off.

Core sketch: Smartlight.ino
Optional extra (clap toggle demo): SoundSensor.ino

Hardware and wiring

• ESP32 development board
• HC‑SR04 ultrasonic sensor
• KY‑016 RGB LED + 3 current‑limiting resistors (e.g., 220 Ω)

Pins (from Smartlight.ino):

• HC‑SR04
  • TRIG → GPIO 23
  • ECHO → GPIO 18
  • VCC → 5V, GND → GND
  • Important: Echo output is 5V. Use a level shifter or resistor divider to ~3.3V before ESP32 GPIO 18.
• KY‑016 RGB LED
  • R → GPIO 2 (through resistor)
  • G → GPIO 4 (through resistor)
  • B → GPIO 5 (through resistor)
  • Common → GND (common‑cathode) is assumed by the code. If your LED is common‑anode (common to 3.3V), invert the duty (e.g., write 255 - value).

Optional clap sensor (separate demo, not used with Wi‑Fi):

• Microphone signal → GPIO 15 (ADC). Note: On ESP32, ADC2 (GPIO 15) can’t be read while Wi‑Fi is active.

Setup

Requirements:

• Arduino IDE with ESP32 boards package (Espressif)
• Libraries: ESPAsyncWebServer, AsyncTCP, NewPing

Configure Wi‑Fi in Smartlight.ino:

const char* ssid = "Your_SSID";
const char* password = "Your_PASSWORD";

Build and flash:

• Select your ESP32 board and port in Arduino IDE, then Upload.
• Open Serial Monitor (115200) to get the assigned IP address.

Use

• Web UI: http:///
• Endpoints:
  • GET /led/on → turn light on
  • GET /led/off → turn light off

How it works (quick)

• Every ~300 ms, the HC‑SR04 distance is sampled via NewPing.
• If distance > 0 and < 8 cm and not in debounce, the code toggles the current light state and starts a 2 s debounce.
• Web commands keep the state in sync and immediately update the RGB output.

Built in a 24‑hour hackathon by:

• Jennifer Corte
• Aleanny Burgos
• Christian Ramirez
• Jeraldine Rodriguez