🌍 ESP32 GPS Monitor with OLED Display & WiFi Dashboard

Real-time GPS monitoring system with an OLED display and WiFi dashboard, built on ESP32 + NEO-6M GPS.

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✨ Project Story – From Curiosity to Creation

This project didn’t start with a circuit diagram. It started with a simple question from my 6-year-old while riding the MRT in Malaysia:

"තාත්තා, how do all the lights on those tall buildings blink together?"

I didn’t have an answer at the time. Later, I discovered that many skyscraper lights are actually synchronized using GPS signals. Each light gets a precise time signal, so they blink in perfect unison — like the city itself is breathing.

That small discovery lit a spark 💡. Why not build something ourselves using GPS?

📖 Read the backstory here: A Little Question, A Big Wonder (LinkedIn)
https://www.linkedin.com/posts/hasithaprabhath_curiosity-parenting-diyprojects-activity-7360663645384593411-XU2c

What began as a child’s innocent curiosity has grown into this project: a real-time GPS monitor that displays data on an OLED screen and serves a live dashboard over WiFi.

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🚀 Features

• 📡 GPS Data Parsing – UTC time, date, latitude, longitude, altitude, speed, and course.
• 🛰️ Satellite Tracking – Satellite count, fix quality, and fix status.
• 🖥️ OLED Display – Minimal, glanceable UI for live data.
• 🌐 WiFi Web Dashboard – ESP32 runs as an Access Point with a responsive dashboard.
• 🔴 LED Fix Indicator – Slow blink = GPS fix, fast blink = searching.
• 🔒 Offline Mode – Works without internet (local WiFi AP mode).

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🛠️ Hardware Requirements

• ESP32 DevKit V1
• NEO-6M GPS Module (3.3V power only ⚠️)
• SSD1306 OLED Display (128x64, I2C)
• USB cable for flashing & power

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🔌 Demo

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🔌 Circuit Diagram

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🌐 WiFi Access Point Details

• SSID: ESP32_GPS_Monitor
• Password: gps123456
• Access URL: http://192.168.4.1

The ESP32 hosts a small web server with three routes:

• / – dashboard (HTML + JS auto-refresh every 2s)
• /data – returns live JSON (time, date, coordinates, speed, fix info)
• /style.css – lightweight styling for the dashboard

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🖥️ Web Dashboard

The dashboard shows:

• Status Bar – GPS Fix vs No Fix, Satellite count
• Date & Time – UTC from GPS
• Position – Latitude & Longitude (DMS → decimal conversion handled in code)
• Measurements – Altitude (m), Speed (km/h), Course (deg)
• Signal Info – Fix quality, Fix status, Last update timestamp

The OLED updates ~every 500 ms; the browser fetches /data every 2 seconds.

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📂 Project Files

• esp32_gps.ino → Main Arduino sketch (GPS parsing, OLED UI, WiFi server).
• docs/circuit-diagram.svg

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🚀 Getting Started

1. Clone

   git clone https://github.com/hasithaishere/esp32-gps-oled-wifi-monitor.git
   cd esp32-gps-oled-wifi-monitor

2. Install Arduino libraries

   • Adafruit SSD1306
   • Adafruit GFX
   • WiFi
   • WebServer

3. Wire up GPS & OLED as per the diagram.

4. Flash the sketch esp32_gps.ino to your ESP32 (Board: ESP32 Dev Module).

5. Connect to the ESP32 WiFi AP:

   • SSID: ESP32_GPS_Monitor
   • Password: gps123456

6. Open http://192.168.4.1 in your browser to view live data.

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🧠 How It Works (Quick Technical Notes)

• Serial & Parsing: GPS NMEA sentences are read from UART2 and parsed for GGA, RMC, and GSV. Time/position are decoded; speed in knots is converted to km/h.
• Coordinate Conversion: Raw ddmm.mmmm / dddmm.mmmm are converted to decimal degrees with hemisphere sign handling (S/W negative).
• Staleness & Fix: If no sentence is received for 5s, the system flags hasValidFix = false. LED blink interval is tied to fix status.
• OLED UI: Large time header with supporting rows for sats/lat/lon/date for quick glances.
• Web API: /data returns a compact JSON snapshot for simple integrations or future logging.

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🔮 Roadmap / Ideas

• Log GPS tracks to SD card (CSV/GeoJSON)
• Google Maps integration for live plotting
• NTP fallback for time when under poor sky view
• Turn the dashboard into a PWA (installable on phones)
• Add PPS pin handling for timing experiments

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📜 License

MIT License © Hasitha Prabhath Gamage

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Sometimes, the best engineering projects start with the smallest voices — in this case, a child’s question about blinking lights.