GoPro Time Sync

Automatic time synchronization for GoPro Hero 9/10/11 cameras using ESP32 and DS3231 RTC module.

Overview

This project automatically synchronizes your GoPro camera's internal clock with an accurate DS3231 RTC module via an ESP32. The ESP32 connects to the GoPro over BLE, enables its WiFi access point, and sets the time using the legacy HTTP API. It continuously monitors the connection and automatically re-syncs when the GoPro is powered back on.

Features

✅ Automatic Time Sync - Reads accurate time from DS3231 RTC and syncs to GoPro
✅ Auto-Reconnection - Detects GoPro power cycles and automatically reconnects
✅ Periodic Updates - Re-syncs time every hour while connected
✅ Audio Feedback - Buzzer beeps once on successful time sync
✅ Full BLE + WiFi Handling - Manages BLE connection, WiFi AP enable, and WiFi connection
✅ Clean Code - Simplified, well-documented, production-ready

Hardware Requirements

ESP32 Development Board (any variant with BLE support)
DS3231 RTC Module (I2C interface with battery backup)
Buzzer (passive or active, 3.3V-5V compatible)
GoPro Hero 9, 10, or 11 Camera
USB cable for programming ESP32
Jumper wires for connections

Wiring

DS3231 RTC Module

DS3231	ESP32
VCC	3.3V
GND	GND
SDA	GPIO 21
SCL	GPIO 22

Buzzer

Buzzer	ESP32
+	GPIO 25
-	GND

Notes:

Ensure your DS3231 has a backup battery (CR2032) installed to maintain accurate time when powered off

The buzzer will beep once (200ms) whenever time is successfully synchronized

You can change the buzzer pin by modifying BUZZER_PIN in the code (default: GPIO 25)

Software Requirements

PlatformIO (recommended) or Arduino IDE
Libraries (auto-installed with PlatformIO):
- NimBLE-Arduino @ ^1.4.2
- RTClib @ ^2.1.1
- ESP32 Arduino Framework

Installation

Using PlatformIO (Recommended)

Clone this repository:

git clone https://github.com/yourusername/gopro-timecode.git
cd gopro-timecode

Open the project in PlatformIO:
```
cd "gopro time sync"
pio run
```
Upload to your ESP32:
```
pio run --target upload
```
Monitor the serial output:
```
pio device monitor
```

Using Arduino IDE

Install the required libraries via Library Manager:
- NimBLE-Arduino
- RTClib by Adafruit
Open gopro time sync/src/main.cpp in Arduino IDE
Select your ESP32 board and upload

How It Works

Initial Setup Flow

RTC Initialization - Reads current time from DS3231 module
BLE Scan - Scans for nearby GoPro cameras
BLE Connection - Connects to the GoPro via Bluetooth LE
WiFi Credentials - Reads SSID and password from GoPro
Enable WiFi AP - Tells GoPro to turn on its WiFi access point
WiFi Connection - ESP32 connects to GoPro's WiFi network
Time Sync - Sets GoPro time via HTTP API
Audio Confirmation - Buzzer beeps to confirm successful sync
Monitoring - Continuously monitors connection status

Automatic Reconnection

When the GoPro is powered off and back on:

ESP32 detects WiFi disconnection
Waits 5 seconds then attempts reconnection
Performs full reconnection routine (BLE → WiFi AP → WiFi)
Immediately syncs time after reconnection
Retries every 5 seconds until successful
Continues monitoring once connected

Periodic Sync

While connected, the ESP32 automatically re-syncs the time every hour to maintain accuracy.

API Endpoint Used

The project uses the legacy GoPro HTTP API endpoint:

GET http://10.5.5.9/gp/gpControl/command/setup/date_time?p=%YY%MM%DD%HH%MM%SS

Where parameters are hex-encoded:

YY - Year (2 digits, e.g., 0x19 = 2025)
MM - Month (1-12)
DD - Day (1-31)
HH - Hour (0-23)
MM - Minute (0-59)
SS - Second (0-59)

Configuration

You can adjust timing and buzzer parameters in main.cpp:

// Timing Configuration
#define SCAN_TIME_SECONDS 10              // BLE scan duration
#define BLE_CONNECT_TIMEOUT_MS 15000      // BLE connection timeout
#define WIFI_CONNECT_TIMEOUT_MS 20000     // WiFi connection timeout
#define AP_READY_POLL_ATTEMPTS 25         // WiFi AP ready polling attempts

// Buzzer Configuration
#define BUZZER_PIN 25                     // GPIO pin for buzzer
#define BEEP_DURATION_MS 200              // Beep duration (milliseconds)

Reconnection timing (in loop()):

if (!isConnected && (millis() - lastReconnectAttempt > 5000)) {  // 5 seconds
    // Reconnection logic
}

if (isConnected && (millis() - lastSync > 3600000)) {  // 1 hour
    // Periodic sync logic
}

Buzzer Feedback

Single beep (200ms) - Time synchronized successfully ✅

The buzzer only beeps on successful time sync to avoid annoying error notifications. Check the serial monitor for detailed error messages if time sync fails.

Python Script (Windows Only)

The scripts/wifi_ap_enable.py script is a standalone Windows demonstration that shows how to connect to a GoPro using Python's open_gopro library.

This script is NOT required for the ESP32 project and serves only as a reference implementation for understanding the GoPro BLE/WiFi connection process.

To run the Python script (optional):

pip install -r requirements.txt
python scripts/wifi_ap_enable.py

Note: The Python script requires Windows and a Bluetooth adapter. It was used during development to understand the GoPro API but is not part of the final ESP32 solution.

Serial Monitor Output Example

==================================
ESP32 GoPro Time Sync
==================================

[RTC] Initializing DS3231 RTC...
[RTC] Current time: 2025-11-16 04:38:04
[BLE] Initializing BLE...
[BLE] Scanning for GoPro devices...
[BLE] Found GoPro: GoPro 9953 (f4:03:28:96:36:4a)
[BLE] Connecting to GoPro at f4:03:28:96:36:4a...
[BLE] Connected to GoPro
[BLE] Getting WiFi SSID...
[BLE] WiFi SSID: GP50029953
[BLE] Getting WiFi password...
[BLE] WiFi password: r#P-jP7-bD3
[BLE] Enabling WiFi AP...
[BLE] WiFi AP enable command sent successfully
[BLE] AP Mode status: 0x03
[BLE] AP is ready and broadcasting!
[WiFi] Connecting to GoPro AP: GP50029953...
[WiFi] Connected! IP: 10.5.5.110
[HTTP] Setting GoPro date/time...
[HTTP] URL: http://10.5.5.9/gp/gpControl/command/setup/date_time?p=%19%0b%10%04%26%04
[HTTP] Time synchronized successfully!

[SUCCESS] Date/time synchronized!

==================================
Setup complete!
==================================

Troubleshooting

GoPro Not Found

Ensure GoPro Bluetooth is enabled
Put GoPro in pairing mode: Preferences > Connections > Connect Device > GoPro App
Check if GoPro is already connected to another device

BLE Connection Fails

Move ESP32 closer to GoPro
Restart both ESP32 and GoPro
Check serial monitor for specific error messages

WiFi Connection Fails

Verify WiFi credentials were read correctly
Ensure GoPro WiFi AP is enabled (check GoPro screen)
Check if another device is connected to GoPro WiFi

Time Not Syncing

Verify DS3231 RTC has correct time
Check if DS3231 battery is installed
Monitor serial output for HTTP response codes
Ensure GoPro firmware is up to date

Reconnection Issues

ESP32 automatically retries every 5 seconds
Check serial monitor for reconnection attempts
Verify GoPro remains in WiFi mode after boot
Ensure GoPro has fully booted before first retry attempt

Compatible GoPro Models

This project has been tested with:

✅ GoPro Hero 9 Black
✅ GoPro Hero 10 Black (should work)
✅ GoPro Hero 11 Black (should work)

Older models (Hero 5-8) may work but use different BLE protocols and are not officially supported.

Project Structure

gopro-timecode/
├── gopro time sync/          # ESP32 PlatformIO project
│   ├── src/
│   │   └── main.cpp          # Main ESP32 application
│   ├── platformio.ini        # PlatformIO configuration
│   └── lib/                  # Libraries folder
├── scripts/
│   └── wifi_ap_enable.py     # Python demo script (Windows only)
├── requirements.txt          # Python dependencies (for demo script)
└── README.md                 # This file

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

License

This project is open source and available under the MIT License.

Acknowledgments

Author

Created for automatic GoPro timecode synchronization in multi-camera setups.

Note: This project is not affiliated with or endorsed by GoPro, Inc. GoPro is a registered trademark of GoPro, Inc.

Name		Name	Last commit message	Last commit date
Latest commit History 8 Commits
gopro time sync		gopro time sync
scripts		scripts
.gitignore		.gitignore
README.md		README.md
cohn_db.json		cohn_db.json
requirements.txt		requirements.txt

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