#define BLYNK_PRINT Serial
#define BLYNK_TEMPLATE_ID "TMPL6SDwaG6I0"
#define BLYNK_TEMPLATE_NAME "Traffic light by Thieu Quang"
#define BLYNK_AUTH_TOKEN "8MKkq6ab3XxXDlLmM0bZAcUSL8-1XqmH"
#define pinRed 12
#define pinYellow 27
#define pinGreen 25
#include <WiFi.h>
#include <WiFiClient.h>
#include <LiquidCrystal_I2C.h>
#include <BlynkSimpleEsp32.h>
BlynkTimer timer;
LiquidCrystal_I2C lcd(0x27, 16, 2); // I2C address 0x27, 16 column and 2 rows
char auth[] = BLYNK_AUTH_TOKEN;
char ssid[] = "Wokwi-GUEST";
char pass[] = "";
// Traffic light timing variables (in seconds)
int greenTime = 10;
int yellowTime = 3;
int redTime = 10;
// Function to update the traffic light status
void updateTrafficLight() {
// Green
digitalWrite(pinGreen, HIGH);
lcd.setCursor(0, 0);
lcd.print("Green: ");
for (int i = greenTime; i >= 0; i--) {
lcd.setCursor(7, 0);
lcd.print(i);
delay(1000);
// Clear the display before updating the next digit
lcd.setCursor(0, 0);
lcd.print("Green: ");
}
digitalWrite(pinGreen, LOW);
// Yellow
digitalWrite(pinYellow, HIGH);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Yellow: ");
for (int i = yellowTime; i >= 0; i--) {
lcd.setCursor(8, 0);
lcd.print(i);
delay(1000);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Yellow: ");
}
digitalWrite(pinYellow, LOW);
// Red
digitalWrite(pinRed, HIGH);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Red: ");
for (int i = redTime; i >= 0; i--) {
lcd.setCursor(7, 0);
lcd.print(i);
delay(1000);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Red: ");
}
digitalWrite(pinRed, LOW);
}
BLYNK_CONNECTED(){
Blynk.syncVirtual(V0);
Blynk.syncVirtual(V1);
Blynk.syncVirtual(V2);
}
BLYNK_WRITE(V0) {
greenTime = param.asInt();
}
BLYNK_WRITE(V1) {
yellowTime = param.asInt();
}
BLYNK_WRITE(V2) {
redTime = param.asInt();
}
void setup() {
Serial.begin(9600);
Blynk.begin(auth, ssid, pass);
pinMode(pinRed, OUTPUT);
pinMode(pinYellow, OUTPUT);
pinMode(pinGreen, OUTPUT);
// Initial state
digitalWrite(pinRed, HIGH); // Red
lcd.init( );
lcd.backlight();
}
void loop() {
Blynk.run();
timer.run();
updateTrafficLight();
}