#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#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
#define TRIG_PIN 3
#define ECHO_PIN 4
int count = 0;
long duration;
int distance;
bool objectDetected = false; // To avoid multiple counts for the same object
void setup() {
// Initialize serial monitor
Serial.begin(9600);
// Pin modes
pinMode(TRIG_PIN, OUTPUT);
pinMode(ECHO_PIN, INPUT);
// OLED initialization
if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
Serial.println(F("SSD1306 allocation failed"));
for (;;);
}
display.clearDisplay();
display.setTextSize(1); // Smaller text to fit OLED
display.setTextColor(SSD1306_WHITE);
display.setCursor(0, 10);
display.println("Head Counter");
display.display();
delay(2000);
}
void loop() {
// Send 10us pulse to trigger pin
digitalWrite(TRIG_PIN, LOW);
delayMicroseconds(2);
digitalWrite(TRIG_PIN, HIGH);
delayMicroseconds(10);
digitalWrite(TRIG_PIN, LOW);
// Read echo pin
duration = pulseIn(ECHO_PIN, HIGH);
distance = duration * 0.034 / 2; // Convert to cm
Serial.print("Distance: ");
Serial.println(distance);
// If object is within 15 cm and was not previously detected
if (distance < 50 && !objectDetected) {
count++;
objectDetected = true;
// Update OLED
display.clearDisplay();
display.setTextSize(1);
display.setCursor(0, 20);
display.print("Count: ");
display.println(count);
display.display();
delay(500);
}
// Reset detection when object moves away
if (distance > 20) {
objectDetected = false;
}
delay(100);
}