This documentation is still being improved and under construction!

Both electrical and software synchronization are required. See below for detailed instructions.

Electrical Wiring Guide

Leader-Follower Mode
Follower-Only Mode (External Clock)

Overview

This mode is designed for configurations not using an External Clock Signal.You will utilize one camera in leader mode (outputting a synchronization signal) and all remaining cameras in follower mode.

Leader/Follower Firmware Guide

Click here to see our guide on updating your camera between Leader and Follower modes.

Wiring

Example

Overview

This mode is designed for configurations using an External Clock Signal to output the synchronization signal for all cameras.In this mode, all cameras must be set to follower mode.

Leader/Follower Firmware Guide

Click here to see our guide on updating your camera between Leader and Follower modes.

Wiring

Check your specific device’s product page for external frame-syncing specifications.

External Clock Signal Generation

Arduino Integration

The Arduino Uno (ATmega328P) is currently the only confirmed working board for this configuration.

Download the PWM Library

Download the source code for the PWM library here: ArduinoPWM v1.0.0

Add the .ZIP Library

Import the downloaded .ZIP library into your Arduino IDE.

Upload the Sketch

Upload one of the two sketches below to your Arduino.

Simple Control: The quickest way to get started, but requires reflashing the firmware to adjust your FPS.
Serial Control: Allows you to adjust frequency and duty cycle in real-time without reflashing (settings will reset if the device loses power).

Simple Control
Serial Commands

#include <PWM.h>

// Pin configuration
int pin = 9;       // Pin
int value = 127;   // Initial value for the PWM duty cycle

// SET FREQUENCY HERE
float frequency = 60; // Initial frequency in Hz

void setup()
{
    // Initialize all timers except for timer0 to save timekeeping tasks
    InitTimersSafe();

    // Set the initial PWM frequency and duty cycle
    if (SetPinFrequencySafe(pin, frequency))
    {
        pwmWrite(pin, value);
        Serial.println("PWM frequency and initial duty cycle set.");
    }
    else
    {
        Serial.println("Failed to set frequency.");
    }
}

#include <PWM.h>

// Pin configuration
int pin = 9;          // Pin
int value = 127;      // Initial value for the PWM duty cycle
float frequency = 60; // Initial frequency in Hz

void setup()
{
    Serial.begin(9600);

    // Initialize all timers except for timer0 to save timekeeping tasks
    InitTimersSafe();

    // Set the initial PWM frequency and duty cycle
    if (SetPinFrequencySafe(pin, frequency))
    {
        pwmWrite(pin, value);
        Serial.println("PWM frequency and initial duty cycle set.");
    }
    else
    {
        Serial.println("Failed to set frequency.");
    }
}

void loop()
{
    if (Serial.available())
    {
        // Read frequency and duty cycle values over Serial
        String inputString = Serial.readStringUntil('\n'); 
        inputString.trim();                                
        int freqDutySplitIndex = inputString.indexOf(',');

        if (freqDutySplitIndex != -1)
        {
            String freqStr = inputString.substring(0, freqDutySplitIndex);  
            String dutyStr = inputString.substring(freqDutySplitIndex + 1); 

            // Parse floats
            float newFrequency = freqStr.toFloat();
            int newDutyCycle = dutyStr.toInt();

            // Validate frequency range
            if (newFrequency >= 1 && newFrequency <= 2000000)
            {
                // Set the PWM frequency and apply duty cycle
                if (SetPinFrequencySafe(pin, newFrequency))
                {
                    value = map(constrain(newDutyCycle, 0, 100), 0, 100, 0, 255);
                    pwmWrite(pin, value);
                    Serial.print("Set frequency to: ");
                    Serial.print(newFrequency);
                    Serial.print(" Hz, duty cycle to: ");
                    Serial.print(newDutyCycle);
                    Serial.println("%");
                }
                else
                {
                    Serial.println("Failed to set new frequency.");
                }
            }
            else
            {
                Serial.println("Invalid frequency value.");
            }
        }
        else
        {
            Serial.println("Invalid input format. Use frequency,dutycycle (e.g., 60,50).");
        }
    }
}

This code allows you to modify the PWM signal on the fly. Open your serial monitor at 9600 baud and send commands using the format {FREQUENCY},{DUTY_CYCLE} (e.g., 60,50 for 60Hz at a 50% duty cycle).

Synchronized Video Python Library (Linux)

In addition to our upcoming SDK, we currently provide a simple Python process to grab synchronized frames from your camera setups. (Note: This may be phased out in favor of the fully featured SDK in the future.)

Synchronized Video Python Library

Follow our GitHub guide to install and use our custom Linux, python library.

Synchronized Stitched Video

This will go over using GStreamer to synchronize and stitch two video feeds. Then, creating a virtual device to use in other programs.

Linux

Install Required Packages

Install the necessary dependencies using the following command:

sudo apt install -y libx264-dev libjpeg-dev \
libglib2.0-dev libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev \
gstreamer1.0-tools gstreamer1.0-x gstreamer1.0-plugins-base gstreamer1.0-plugins-good \
gstreamer1.0-plugins-bad gstreamer1.0-libav libgstreamer-plugins-bad1.0-dev \
gstreamer1.0-plugins-ugly gstreamer1.0-gl \
v4l-utils

List Current Camera Devices

Run the following command to find your connected cameras:

v4l2-ctl --list-devices

Example output:

stellarHD Leader: stellarHD Lea (usb-0000:00:14.0-8.3):
    /dev/video0
    /dev/video1
    /dev/media0

stellarHD Follower: stellarHD F (usb-0000:00:14.0-8.4):
    /dev/video2
    /dev/video3
    /dev/media1

Create a Virtual Device

Identify the device IDs of the two cameras you wish to use, then select a device ID number that is not currently listed.In this example, we will use 9 (as it is unused above) to create a virtual device named stellarHD_stitched. Update the 9 in the command below to match your chosen unused ID:

sudo modprobe v4l2loopback video_nr=9 \
card_label=stellarHD_stitched exclusive_caps=1

Launch the GStreamer Pipeline

Launch the pipeline to create the stitched video and output the stream to your new virtual device:

gst-launch-1.0 -v \
compositor name=mix \
    sink_0::xpos=0    sink_0::ypos=0   sink_0::alpha=1 \
    sink_1::xpos=1600 sink_1::ypos=0   sink_1::alpha=1 \
! jpegenc ! jpegdec ! videoconvert ! v4l2sink device=/dev/video9 \
v4l2src device=/dev/video0 ! image/jpeg,width=1600,framerate=60/1 ! jpegdec ! videorate ! mix.sink_0 \
v4l2src device=/dev/video2 ! image/jpeg,width=1600,framerate=60/1 ! jpegdec ! videorate ! mix.sink_1

You must keep this command running while using the synchronized, stitched videos. You can modify this command to add more cameras, change resolutions/framerates, or alter the layout.

Use the Virtual Device in OpenCV

OpenCV Starter Code

Follow our sample code to use /dev/video9 in OpenCV.

Remove the Loopback Device

To safely remove the loopback device, you can either restart your computer or run the following sequence of commands:1. Identify programs currently using the loopback device:

sudo lsof /dev/video*

2. Kill the processes using their PID (Process ID) numbers:

sudo kill <INSERT_PID_NUMBER>

3. Remove the loopback device:

sudo modprobe -r v4l2loopback

Overview

Specifications

Guides

Frame-Synchronizing Multiple Cameras

Electrical Wiring Guide

Overview

Leader/Follower Firmware Guide

Wiring

Example

Overview

Leader/Follower Firmware Guide

Wiring

External Clock Signal Generation

Arduino Integration

Synchronized Video Python Library (Linux)

Synchronized Video Python Library

Synchronized Stitched Video

OpenCV Starter Code

​Electrical Wiring Guide

​Overview

Leader/Follower Firmware Guide

​Wiring

​Example

​Overview

Leader/Follower Firmware Guide

​Wiring

​External Clock Signal Generation

​Arduino Integration

​Synchronized Video Python Library (Linux)

Synchronized Video Python Library

​Synchronized Stitched Video

OpenCV Starter Code

Electrical Wiring Guide

Overview

Wiring

Example

Overview

Wiring

External Clock Signal Generation

Arduino Integration

Synchronized Video Python Library (Linux)

Synchronized Stitched Video