ESP32-S3 vehicle telemetry and GPS tracker streaming location and vehicle status over Cat-M/NB-IoT cellular networks.

Status: in progress

What it does

• Tracks real-time GNSS location and reports vehicle coordinates over Cat-M / NB-IoT cellular data
• Manages power and deep sleep based on car ignition status to preserve vehicle battery
• Processes remote configuration and trigger commands via SMS and HTTP polling
• Supports over-the-air (OTA) firmware updates, geofencing, and ESP-NOW local fallbacks

Bill of Materials

Part	Quantity	Purpose
ESP32-S3 Development Board	1	Microcontroller running modular C++ telemetry firmware
Waveshare Pico SIM7080G Module	1	Cat-M / NB-IoT cellular modem & GNSS positioning engine
Hologram SIM Card	1	Global IoT cellular data connectivity
12V-to-5V Buck Converter	1	Steps down car 12V DC power to 5V DC circuit power
LiPo Battery Charge Controller	1	Manages backup LiPo battery during vehicle power loss

How it works

Firmware isolates hardware control into dedicated C++ modules (GNSS, Modem, PowerMgr). Cellular communication uses AT commands over UART (Serial2, 9600 baud on pins 16/17) with dedicated power control on GPIO 4. Telemetry payloads are packaged into JSON and pushed via HTTP POST to the Laravel backend.

What broke

• SIM7080G cold-boot PDP context attach required exact pulse timing on the PWR pin (GPIO 4) to ensure modem initialization before issuing AT+CGNSPWR=1 for GNSS power.

Links

• Web Dashboard: CAR_GPS_REACT
• Backend API: Laravel-GPS-API