GPS Tracker Using Arduino, SIM800L, and NEO-6M

Have you ever wanted to track your car, bike, or pet in real time using your own tracking device, instead of a commercial GPS tracker or a monthly subscription service? This DIY Arduino project uses the Arduino UNO, SIM800L GSM module, and NEO-6M GPS module to create a tracking system and connect it to a dashboard called GeoLinker that's completely free to use, and designed for hobby projects like this one!

What You'll Build

A complete GPS tracking system that:

• Captures real-time location data via GPS.
• Sends it to a cloud platform using GSM.
• It lets you visualize the path live on a web-based map.
• Costs under $30 with no subscription fee at all.

Note: Jio SIM won’t work in India (2G not supported). Use Airtel/Vi/BSNL.

Why Build Your Own Tracker?

• First of all, no monthly fees - Just a SIM with data
• Open Source & Fully Customizable
• GeoLinker Cloud Dashboard: You get a real-time view, speed/distance logs
• Arduino-Compatible: Works with Uno R3 and similar boards
• GeoLinker Lite Library: Memory-optimized for ATmega328P boards

How It Works

• The NEO-6M GPS module gets your location from satellites.
• The Arduino UNO processes that.
• The SIM800L GSM module sends data to the GeoLinker cloud through HTTP.
• You see your track on the GeoLinker Dashboard with timestamped points.

Circuit Diagram & Wiring

Key Connection Notes:

• GPS TX → Arduino RX (Pin 0)
• SIM800L TX → Arduino Pin 9
• SIM800L RX ← Arduino Pin 8 via voltage divider
• SIM800L VCC ← Arduino 5V (via diode for ~4.3V drop)
• Arduino Pin 2 → Arduino RESET pin (for switching between GPS and GSM modes)

GeoLinker Lite Library

To make things as simple as possible, we built a lightweight Arduino library just for this. It handles:

• GPS parsing
• SIM800L communication
• Cloud integration via HTTP

Install It:

• Open up Arduino IDE
• Go to Sketch > Include Library > Manage Libraries
• Search for GeoLinker Lite
• Hit Install

Or download it from GitHub: GeoLinkerLite GitHub

Just replace the placeholders with your own APN and API key.

#include <GeoLinkerLite.h>
GeoLinkerLite geoLinker(Serial, Serial);
void setup() {
Serial.begin(9600);
delay(1000);
geoLinker.setResetPin(2);
geoLinker.setGSMPins(8, 9);
geoLinker.setModemAPN("your.apn.here"); // Replace this
geoLinker.setAPIKey("your_api_key"); // Replace this
geoLinker.setDeviceID("arduino_tracker");
geoLinker.setMaxRetries(3);
geoLinker.setDebugLevel(1);
geoLinker.setTimeOffset(5, 30); // For India timezone
geoLinker.begin();
delay(1000);
geoLinker.run();
}
void loop() {
delay(1000); // geoLinker.run() handles everything else
}

You can grab your free API key from CircuitDigest Cloud. It’s free, and you can track multiple devices too.

Testing

Once your code is uploaded and everything's connected:

• Head outdoors as the GPS needs a clear sky.
• Open the Serial Monitor at 9600 baud.
• You’ll see GPS lock → GSM connect → data upload.
• Then open GeoLinker and see your tracker’s location live.

Commons Problems

Can’t upload the code?

Unplug the GPS TX wire from Pin 0 first.

Your Arduino keeps resetting?

This is a power supply issue. Use a power bank with 2A output.

No GPS data?

Go outside, wait 2–5 mins for satellite lock. Check the antenna too.

HTTP 401 error?

Double-check your API key. Make sure there are no spaces or typos.

SIM800L not working?

Make sure:

• SIM card is 2G (Jio won’t work)
• You’ve got the voltage divider in place
• The antenna is attached properly

Conclusion

This Arduino GPS tracker that you just built from the ground up is cost-effective and reliable. You can expand this project by adding a buzzer, motion sensor, or even integrate with home automation.

There's a more comprehensive version of this project available here: Arduino GPS Tracker