HW-488 Infrared Obstacle Avoidance Sensor

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

// OLED display dimensions
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1  // Reset pin not used

// Create OLED display object
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Pin definitions
const int sensorOutPin = 2;  // Sensor output pin
const int buzzerPin = 3;     // Buzzer control pin

// Global variables
int obstacleCount = 0;       // Counter for detected obstacles
bool lastObstacleState = false;  // Previous state of obstacle detection

void setup() {
  Serial.begin(9600);
  
  // Configure pin modes
  pinMode(sensorOutPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
  digitalWrite(buzzerPin, LOW);  // Ensure buzzer is off initially
  
  // Initialize OLED display
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("OLED initialization failed"));
    for(;;);  // Halt execution if display fails to initialize
  }
  
  // Clear display and show initial count of 0
  display.clearDisplay();
  display.setTextSize(4);       // Large text size
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(50, 20);    // Centered position
  display.println("0");
  display.display();
  
  Serial.println("System started");
}

void loop() {
  // Read current sensor state (LOW indicates obstacle detected)
  bool currentObstacleState = (digitalRead(sensorOutPin) == LOW);
  
  // Detect state change: no obstacle -> obstacle detected
  if (currentObstacleState && !lastObstacleState) {
    obstacleCount++;       // Increment counter
    triggerAlarm();        // Activate buzzer
    updateDisplay();       // Update count on display
    Serial.print("Count: ");
    Serial.println(obstacleCount);
  }
  
  // Save current state for next comparison
  lastObstacleState = currentObstacleState;
  delay(50);  // Short delay for debouncing
}

// Activate buzzer for brief alert
void triggerAlarm() {
  digitalWrite(buzzerPin, HIGH);
  delay(200);
  digitalWrite(buzzerPin, LOW);
}

// Update OLED display with current count
void updateDisplay() {
  display.clearDisplay();
  display.setTextSize(4);       // Large text size
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(50, 20);    // Centered position
  display.println(obstacleCount);
  display.display();
}