Vehicle Speed Measurement and LCD Output Using Arduino

**Introduction:**Measuring the speed of a vehicle is essential for various applications, from ensuring road safety to optimizing transportation systems. In this article, we will explore how to create a vehicle speed measurement system using an Arduino and display the results on an LCD screen. This project is not only educational but also has practical applications in traffic management, automotive engineering, and even sports.

**Working Principle:**The vehicle speed measurement system relies on the principle of measuring the time it takes for a vehicle to travel a known distance. By dividing the distance by the time taken, we can calculate the speed. To achieve this, we'll use an Arduino microcontroller, a sensor, and an LCD display.

**Things We Need:**To build this project, you will need the following components:

1. Arduino Uno or compatible board.
2. An ultrasonic distance sensor (e.g., HC-SR04).
3. A 16x2 LCD screen with an I2C backpack.
4. Jumper wires.
5. Breadboard or custom PCB for circuit connections.
6. A power source (battery or USB power bank).

Circuit Diagram

Connect the components as follows:

1. Connect the VCC and GND pins of the ultrasonic sensor to 5V and GND on the Arduino.
2. Connect the trigger (TRIG) and echo (ECHO) pins of the sensor to digital pins on the Arduino.
3. Connect the SDA and SCL pins of the LCD I2C backpack to the respective Arduino pins (usually A4 and A5).
4. Connect the VCC and GND pins of the LCD I2C backpack to 5V and GND on the Arduino.
5. Power the Arduino using a USB cable or an external power source.

Working of the System with Arduino

The ultrasonic sensor emits a high-frequency sound wave (ultrasonic) and measures the time it takes for the sound to bounce back after hitting an object (in this case, the passing vehicle).
Arduino calculates the distance to the vehicle using the time measured.
Knowing the distance and the time it took, the Arduino calculates the vehicle's speed.
The speed value is then displayed on the LCD screen through the I2C interface.

Arduino CodeHere's a basic Arduino sketch to get you started:

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
 
LiquidCrystal_I2C lcd(0x27, 16, 2); // Initialize the LCD screen
 
const int trigPin = 2; // Trigger pin of the ultrasonic sensor
const int echoPin = 3; // Echo pin of the ultrasonic sensor
 
void setup() {
  lcd.init(); // Initialize the LCD
  lcd.backlight();
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  Serial.begin(9600);
}
 
void loop() {
  long duration, distance;
  
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
 
  duration = pulseIn(echoPin, HIGH);
  distance = (duration * 0.0343) / 2;
  
  int speed = 3600 * distance / 1000; // Convert to km/h
 
  lcd.setCursor(0, 0);
  lcd.print("Speed: ");
  lcd.print(speed);
  lcd.print(" km/h  ");
 
  delay(1000);
  lcd.clear();
}

Conclusion:
By following this project, you can create a vehicle speed measurement system using an Arduino and an ultrasonic sensor. The system calculates the speed of passing vehicles and displays the results on an LCD screen. This project is a great way to learn about Arduino, sensors, and data display while also having practical applications in traffic monitoring and automotive engineering. Experiment with different sensors and display options to enhance the functionality of your vehicle speed measurement system.