#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Wire.h>
// OLED Display settings
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
// Ultrasonic Sensor pins
const int trigPin = 9;
const int echoPin = 10;
// LED and Buzzer pins
const int ledPin = 6;
const int buzzerPin = 7;
void setup() {
Serial.begin(9600);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(ledPin, OUTPUT);
pinMode(buzzerPin, OUTPUT);
// Initialize OLED
if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("OLED display not found!"));
while (true); // Stop here
}
display.clearDisplay();
display.setTextSize(1);
display.setTextColor(SSD1306_WHITE);
}
void loop() {
// Trigger pulse
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Read echo time
long duration = pulseIn(echoPin, HIGH);
// Convert to distance
float distanceCM = duration * 0.034 / 2;
float distanceInches = distanceCM / 2.54;
// Display on OLED
display.clearDisplay();
display.setCursor(0, 10);
display.setTextSize(2);
display.print("CM: ");
display.println(distanceCM, 1);
display.setCursor(0, 35);
display.setTextSize(2);
display.print("In: ");
display.println(distanceInches, 1);
display.display();
// Alert section
if (distanceCM <= 10) {
digitalWrite(ledPin, HIGH);
// Beeping like bomb
for (int i = 0; i < 3; i++) {
tone(buzzerPin, 1000); // Beep sound
delay(100);
noTone(buzzerPin);
delay(100);
}
} else {
digitalWrite(ledPin, LOW);
noTone(buzzerPin);
}
delay(500); // Refresh every 0.5 seconds
}