DIY Location Tracker using GSM SIM800 and Arduino

This DIY location tracker system is built around an Arduino Nano or Uno, which serves as the central brain powered by the ATmega328P microcontroller. When an incoming phone call is detected by the system, the Arduino processes the event and communicates with the SIM800 GSM module via serial commands. The SIM800 module handles cellular network connectivity using a standard SIM card inserted into its 6-pin holder. Upon receiving the call, the Arduino triggers the SIM800 to send an SMS containing a Google Maps location link back to the caller's phone number. To ensure reliable operation, the electronics are mounted on a Custom PCB. Because the SIM800 module requires a specific supply voltage between 3.7V and 4.2V and draws high current bursts during cellular transmission, an LM2596 Buck Converter IC steps down the main DC input power efficiently. Additionally, an AMS1117 3.3V regulator is utilized to provide a stable, clean secondary logic voltage level for components requiring 3.3V. Passive components such as resistors, capacitors, and inductors are integrated throughout the custom board to filter noise, stabilize voltages, and support the switching regulator circuit.