Multi-Device Synchronization Example

Demonstrates multi-device synchronization. This sample supports network devices, USB devices, and GMSL devices.

• The primary purpose of this repository is to demonstrate the multi-device synchronization functionality of different types of Orbbec devices, including detailed instructions for hardware connections and software configuration.
• The v2-main branch is based on the multi device sync sample and gmsl trigger sample provided by Orbbec SDK v2. If there are any updates or changes to the samples in Orbbec SDK v2, please refer to the official implementation in Orbbec SDK v2 as the authoritative version.
• The legacy main branch is based on Orbbec SDK v1 and only demonstrates multi-device synchronization for Femto Mega.

Supported Device Series

Product Series	Product	Connection	Sync Documentation
Gemini 305	Gemini 305	USB	Gemini301Series.md
Gemini 305g	Gemini 305g	USB/GMSL	Gemini301Series.md
Gemini 435Le	Gemini 435Le	Ethernet	Gemini435Le.md
Gemini 330	Gemini 335Le	Ethernet	Gemini330Series.md
	Gemini 335/335L/336/336L	USB	Gemini330Series.md
	Gemini 335Lg	GMSL	Gemini330Series.md
Gemini 2	Gemini 2/2L/215/210	USB	Gemini2Series.md
Astra	Astra 2	USB	Astra2.md
Femto	Femto Bolt	USB	FemtoSeries.md
	Femto Mega	USB/Ethernet	FemtoSeries.md
	Femto Mega I	Ethernet	FemtoSeries.md

Program Overview

This project builds two standalone executables:

Program	Connection	Platform	Function
MultiDeviceSync	USB / Ethernet /GMSL	Windows / Linux x64 / Linux ARM64	Multi-device sync configuration, data stream acquisition, real-time preview
MultiDeviceSyncGmslTrigger	GMSL	Linux ARM64 (NVIDIA Jetson AGX Orin, NVIDIA Jetson Orin NX)	GMSL PWM hardware trigger signal source

• Notes: GMSL devices require two applications: MultiDeviceSync and MultiDeviceSyncGmslTrigger. The MultiDeviceSyncGmslTrigger application is responsible for sending trigger signals, while USB and Ethernet devices only require the MultiDeviceSync application.

Quick Start

1. Build

cd Multi-Device-Synchronization-Example
mkdir build && cd build
cmake ..
cmake --build . --config Release

Build artifacts are in the build/bin/ directory:

• Windows: MultiDeviceSync.exe
• Linux: MultiDeviceSync, MultiDeviceSyncGmslTrigger

2. Configuration

The program reads ./MultiDeviceSyncConfig.json from the current working directory by default. Device serial numbers can be found using the OrbbecViewer tool or in the program log after connecting devices.

Configuration File Structure

The following example includes all optional fields; use as needed based on your device series:

{
    "version": "1.0.1",
    "configTime": "2026/05/07",
    "devices": [
        {
            "sn": "CP123456789",
            "syncConfig": {
                "syncMode": "OB_MULTI_DEVICE_SYNC_MODE_PRIMARY",
                "depthDelayUs": 0,
                "colorDelayUs": 0,
                "trigger2ImageDelayUs": 0,
                "triggerOutEnable": true,
                "triggerOutDelayUs": 0,
                "framesPerTrigger": 1
            }
        }
    ]
}

Field descriptions:

Field	Type	Required	Description
sn	string	Yes	Device serial number, used to match connected devices
syncConfig.syncMode	string	Yes	Sync mode, see table below for available values
syncConfig.depthDelayUs	int	Yes	IR/Depth/ToF trigger signal input delay (microseconds), increment by 160us per device to achieve staggered exposure
syncConfig.colorDelayUs	int	Yes	RGB trigger signal input delay (microseconds), typically 0
syncConfig.trigger2ImageDelayUs	int	Yes	Delay from trigger signal input to image capture (microseconds), typically 0
syncConfig.triggerOutEnable	bool	Yes	Device trigger signal output enable switch. Set to true for PRIMARY/SECONDARY mode, false for SOFTWARE_TRIGGERING and HARDWARE_TRIGGERING mode
syncConfig.triggerOutDelayUs	int	Yes	Device trigger signal output delay (microseconds), typically 0
syncConfig.framesPerTrigger	int	Yes	Number of frames captured per trigger, only effective in software and hardware trigger modes

syncMode available values:

Mode	Description
OB_MULTI_DEVICE_SYNC_MODE_PRIMARY	Primary mode, outputs sync trigger signal
OB_MULTI_DEVICE_SYNC_MODE_SECONDARY	Secondary mode, receives trigger signal
OB_MULTI_DEVICE_SYNC_MODE_SOFTWARE_TRIGGERING	Software trigger mode, PC controls capture timing
OB_MULTI_DEVICE_SYNC_MODE_HARDWARE_TRIGGERING	Hardware trigger mode, triggered by external hardware signal
OB_MULTI_DEVICE_SYNC_MODE_SECONDARY_SYNCED	Secondary synced variant, starts capturing immediately, auto-aligns when trigger signal is received

3. Run MultiDeviceSync

./MultiDeviceSync

• Enter 0: Configure device sync mode and start streaming
• Enter 1: Start streaming directly (use when devices are already configured)

Keyboard shortcuts:

Key	Function
T	Software trigger capture
ESC	Stop streaming and exit

4. Run MultiDeviceSyncGmslTrigger

For GMSL2 connections to NVIDIA Jetson platforms. Devices must be configured as HARDWARE_TRIGGERING mode.

./MultiDeviceSyncGmslTrigger

• Enter 0: Set trigger frequency (FPS)
• Enter 1: Start PWM trigger signal
• Enter 2: Stop PWM trigger signal
• Enter 3: Exit

Notes

1. Femto series and Gemini 2 series sync configurations are written to Flash and persist after power-off; frequent configuration will reduce Flash lifespan. Gemini 305 and Gemini 330 sync configurations do not persist after power-off and must be reconfigured each time the device is powered on.
2. MultiDeviceSyncGmslTrigger only provides PWM trigger signal source and does not include data stream acquisition or preview functionality.
3. When exiting MultiDeviceSyncGmslTrigger, select 3 to ensure the /dev/camsync device is properly closed.

Project Structure

├── CMakeLists.txt                              # Build configuration
├── MultiDeviceSync/                            # Standard USB/Ethernet multi-device sync
│   └── MultiDeviceSync.cpp                     #   Main program
├── MultiDeviceSyncGmslTrigger/                 # GMSL PWM hardware trigger
│   └── MultiDeviceSyncGmslTrigger.cpp          #   Main program
├── common/                                     # Shared core modules
│   ├── PipelineHolder.hpp/cpp                  #   Pipeline wrapper
│   ├── FramePairingManager.hpp/cpp             #   Cross-device frame pairing
│   └── utils/                                  #   Utility library
│       ├── cJSON.c/h                           #     JSON parser
│       ├── utils.cpp/hpp                       #     Basic utility functions
│       ├── utils_c.c/h                         #     C utility functions
│       ├── utils_opencv.cpp/hpp                #     OpenCV visualization windows
│       └── utils_types.h                       #     Common type definitions
├── config/
│   ├── OrbbecSDKConfig.xml                     # SDK device configuration
│   ├── MultiDeviceSyncConfig.json              # Current sync configuration
├── docs/                                       # Per-series documentation
│   ├── Astra2.md
│   ├── FemtoSeries.md
│   ├── Gemini2Series.md
│   ├── Gemini301Series.md
│   ├── Gemini330Series.md
│   └── Gemini435Le.md
├── res/                                        # Documentation image resources
└── 3rdparty/orbbecsdk/                         # OrbbecSDK
    ├── win_x64/
    ├── linux_x86_64/
    └── linux_arm64/