Circuit Documentation

Summary

This circuit is designed to utilize an Arduino UNO as the central microcontroller to interface with various components including LEDs, a buzzer module, an HC-SR04 ultrasonic sensor, a servo motor, and a power supply consisting of 2x 18650 batteries. The circuit is capable of measuring distance using the ultrasonic sensor and responding to certain distance thresholds by activating LEDs, a buzzer, and a servo motor. A rocker switch is used to control the power supply to the Arduino UNO.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• It has 14 digital input/output pins, 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button.

LED: Two Pin (red)

• A red light-emitting diode with an anode and cathode pin.

LED: Two Pin (green)

• A green light-emitting diode with an anode and cathode pin.

HC-SR04 Ultrasonic Sensor

• An ultrasonic distance sensor with VCC, TRIG, ECHO, and GND pins.

Servo

• A motor capable of precise position control, with ground (gnd), power (vcc), and control (pulse) pins.

2x 18650 Battery Pack

• A power supply unit consisting of two 18650 batteries with vcc and gnd terminals.

Buzzer Module

• An audio signaling device with ground (GND), power (Vcc), and input/output (I/O) pins.

Rocker Switch

• A switch with two terminals used to control the connection of the power supply to the circuit.

Wiring Details

Arduino UNO

• 5V pin connected to Vcc of Buzzer Module, HC-SR04 Ultrasonic Sensor, and Servo.
• GND pin connected to GND of Buzzer Module, HC-SR04 Ultrasonic Sensor, Servo, red LED, green LED, and 2x 18650 Battery Pack.
• D9 pin connected to anode of red LED.
• D8 pin connected to anode of green LED.
• D10 pin connected to I/O of Buzzer Module.
• D7 pin connected to pulse of Servo.
• D6 pin connected to TRIG of HC-SR04 Ultrasonic Sensor.
• D5 pin connected to ECHO of HC-SR04 Ultrasonic Sensor.
• Vin pin connected to terminal 2 of Rocker Switch.

LED: Two Pin (red)

• Cathode connected to GND.
• Anode connected to D9 of Arduino UNO.

LED: Two Pin (green)

• Cathode connected to GND.
• Anode connected to D8 of Arduino UNO.

HC-SR04 Ultrasonic Sensor

• VCC connected to 5V of Arduino UNO.
• TRIG connected to D6 of Arduino UNO.
• ECHO connected to D5 of Arduino UNO.
• GND connected to GND of Arduino UNO.

Servo

• Gnd connected to GND of Arduino UNO.
• Vcc connected to 5V of Arduino UNO.
• Pulse connected to D7 of Arduino UNO.

2x 18650 Battery Pack

• Gnd connected to GND of Arduino UNO.
• Vcc connected to terminal 1 of Rocker Switch.

Buzzer Module

• GND connected to GND of Arduino UNO.
• Vcc connected to 5V of Arduino UNO.
• I/O connected to D10 of Arduino UNO.

Rocker Switch

• Terminal 1 connected to Vcc of 2x 18650 Battery Pack.
• Terminal 2 connected to Vin of Arduino UNO.

Documented Code

#include <Servo.h>

// Definición de pines
const int trigPin = 6;
const int echoPin = 5;
const int redLedPin = 9;
const int buzzerPin = 10;
const int greenLedPin = 8;
const int servoPin = 7;

Servo myServo;

void setup() {
  Serial.begin(9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(redLedPin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
  myServo.attach(servoPin);

  // Estado inicial
  digitalWrite(redLedPin, HIGH);
  digitalWrite(greenLedPin, LOW);
  noTone(buzzerPin); // Detiene el sonido
  myServo.write(0); // Posición inicial del servo
}

void loop() {
  // Medición de distancia
  long duration, distance;
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration / 58.2; // Convertir tiempo a distancia

  // Impresión de variable
  Serial.print("Distancia: ");
  Serial.print(distance);
  Serial.println(" cm");

  // Lógica de control
  if (distance < 7) {
    digitalWrite(redLedPin, LOW);
    digitalWrite(greenLedPin, HIGH);
    myServo.write(90); // Abrir la puerta
    tone(buzzerPin, 220); // Genera un tono de 1000 Hz
    delay(1000); // 1segundo de espera
    noTone(buzzerPin); // Detiene el sonido
    delay(5000); // Mantener abierta por 5 segundos
  } else if (distance >= 10) {
    digitalWrite(redLedPin, HIGH);
    digitalWrite(greenLedPin, LOW);
    noTone(buzzerPin); // Detiene el sonido
    myServo.write(0); // Cerrar la puerta
  }

  delay(100); // Espera para estabilizar las lecturas
}

This code is designed to run on an Arduino UNO and controls the circuit's response to distance measurements taken by the HC-SR04 ultrasonic sensor. When an object is detected within 7 cm, the red LED turns off, the green LED turns on, the servo moves to a 90-degree position, and the buzzer emits a tone for 1 second. If the object is further than 10 cm, the red LED turns on, the green LED turns off, the buzzer stops, and the servo returns to the 0-degree position. The system stabilizes for 100 milliseconds before taking another measurement.