#define BLYNK_TEMPLATE_ID "TMPL3jc_NcE-q"
#define BLYNK_TEMPLATE_NAME "smart traffic diversion system for road congestion"
#define BLYNK_AUTH_TOKEN "Oqz6G-ITkq0ywHrz3EvdPiwi1muURy7Z"
#include <Blynk.h>
#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
// WiFi credentials
const char* ssid = "Wokwi-GUEST";
const char* password = "";
const int trigPin = 5;
const int echoPin = 18;
const int redLED = 23;
const int yellowLED = 22;
const int greenLED = 21;
long duration;
int distance;
void setup() {
Serial.begin(115200);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(redLED, OUTPUT);
pinMode(yellowLED, OUTPUT);
pinMode(greenLED, OUTPUT);
// Connect to Wi-Fi and Blynk
WiFi.begin(ssid, password);
Blynk.begin(BLYNK_AUTH_TOKEN, ssid, password);
Serial.print("Connecting to WiFi ..");
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.print('.');
}
Serial.println("\nConnected to WiFi and Blynk");
}
void loop() {
Blynk.run();
// Clear the trigPin by setting it LOW
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
// Set the trigPin HIGH for 10 microseconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Read the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echoPin, HIGH);
// Calculate the distance
distance = duration * 0.034 / 2;
Serial.print("Distance: ");
Serial.println(distance);
// Traffic light logic based on distance
if (distance < 100) {
digitalWrite(redLED, HIGH);
digitalWrite(yellowLED, LOW);
digitalWrite(greenLED, LOW);
Serial.println("Heavy Traffic Detected: Red Light ON");
Blynk.virtualWrite(V2,HIGH);
Blynk.virtualWrite(V1,LOW);
} else if (distance < 200) {
digitalWrite(redLED, LOW);
digitalWrite(yellowLED, HIGH);
digitalWrite(greenLED, LOW);
Serial.println("Moderate Traffic Detected: Yellow Light ON");
} else {
digitalWrite(redLED, LOW);
digitalWrite(yellowLED, LOW);
digitalWrite(greenLED, HIGH);
Serial.println("Low Traffic Detected: Green Light ON");
Blynk.virtualWrite(V1,HIGH);
Blynk.virtualWrite(V2,LOW);
}
// Send traffic data to Blynk
Blynk.virtualWrite(V0, distance);
delay(10000); // Send data every 10 seconds
}