GPS Tracker

GPS Tracker

Image: Garmin GPS at Greenwich Observatory.jpg by Brian Dell via Wikimedia Commons, Public domain

How It Works

• A GPS module (NEO-6M) continuously receives satellite signals and computes the device's current latitude and longitude.
• The Arduino/microcontroller reads these coordinates from the GPS module's serial output (NMEA sentences).
• A GSM module (SIM800L) sends the coordinates via SMS to a registered phone, or an ESP8266/ESP32 uploads them to an online tracking dashboard over Wi-Fi/cellular data.
• Readings repeat at a set interval, building a continuous location trail rather than a single snapshot.

Components

Arduino Uno / ESP8266 (for Wi-Fi variant)
GPS module (NEO-6M)
GSM module (SIM800L) or Wi-Fi connectivity
Battery pack (vehicle 12V supply for automotive use)

Applications

• Vehicle and fleet location tracking
• Logistics and delivery tracking
• Personal safety/child or elderly location tracking

Advantages

• Continuous, remotely accessible location data, not a one-time check
• SMS fallback works even without a data connection, as long as GSM signal is available
• Compact enough to embed discreetly in a vehicle or bag

Sample Code — Reading GPS Coordinates and Sending via SMS

// Simplified GPS + GSM tracker - Arduino
#include 
TinyGPSPlus gps;

void sendLocationSMS(float lat, float lng) {
  Serial.println("AT+CMGF=1");
  delay(200);
  Serial.println("AT+CMGS=\"+91XXXXXXXXXX\"");
  delay(200);
  Serial.print("Location: http://maps.google.com/?q=");
  Serial.print(lat, 6); Serial.print(","); Serial.print(lng, 6);
  Serial.write(26); // Ctrl+Z to send
}

void loop() {
  while (Serial1.available() > 0) { // GPS module on Serial1
    if (gps.encode(Serial1.read())) {
      if (gps.location.isValid()) {
        sendLocationSMS(gps.location.lat(), gps.location.lng());
        delay(300000); // send every 5 minutes
      }
    }
  }
}

Related Research

• Vehicle Tracking and Anti-theft System using GPS-GSM — IJERT