Microsoft USB Camera Error

Technical C/C++
1

We are trying to use a Microsoft Lifecam HD-3000 as a usb camera through the roborio. We have been using the code from the simple vision example:

CameraServer::GetInstance()->SetQuality(50);
CameraServer::GetInstance()->StartAutomaticCapture(“cam0”);

However, once we start the driver station we get this error:

at /opt/GenICam_v2_3/bin/Linux_armv7-a/libstdc++.so.6(+0xa2cb0) [0xb5e77cb0]Error on line 207 Incompatible State: The operation cannot be completed: Choose “USB Camera HW” on the dashboard
at CameraServer::Serve()

We have eventually gotten the camera feed to show up in java dashboard, but only after creating a couple of different camera objects and then restarting the dashboard. Otherwise it just comes up as connection reset or robot has stopped returning images. Any advice?

2

We debugged this problem (we had it too) and discovered that it’s because CameraServer expects all client information to arrive in one packet. The dashboard sends it in 2 packets, so CameraServer thinks part of the information is missing. You can find our fix for this here.

3

Thanks, a little bit confused on where to put the code though. Does it go inside of a header file?

4

Hey, same problem, appreciate the solution. Where is this file to fix it?

5

FYI, this seems to be a known error:
https://usfirst.collab.net/sf/go/artf4015?nav=1&_pagenum=1&returnUrlKey=1454974655331

6

When using the USB Cameras I would suggest not doing automatic capture. The following is something I made that works. This code is for toggling between two USB cameras, because we have a front and back cam.

CPP File:

/*
 * LHSVision.cpp
 *
 *  Created on: Jan 26, 2016
 *      Author: Michael Conard
 *
 *  THING TO CHECK:
 *  	-In Internet Explorer, roborio-4237-frc.local,
 *  	 confirm the camera names in Silverlight. These
 *  	 should be "cam0", "cam1", or "cam2".
 *
 *  	-These names can be adjusted in the CAMERA
 *  	 namespace.
 */

#include "WPILib.h"
#include "LHSVision.h"

namespace XBOX		//Joystick Constants
{
	const int NODE_ID = 1;

	const int XBOX_A_BUTTON  = 1;
	const int XBOX_X_BUTTON = 3;

	const int XBOX_LEFT_X = 0;
	const int XBOX_LEFT_Y = 1;
}

namespace CAMERA	//Camera Names
{
	const char* CAM_ONE = "cam1";
	const char* CAM_TWO = "cam2";
}

//NOTE: Camera 1 is the default camera. Can toggle to 2 later.
LHSVision::LHSVision(RobotDrive* pRobot, Joystick* pXbox) //Constructor
{
	printf("File %18s Date %s Time %s Object %p
",__FILE__,__DATE__, __TIME__, this);

	frame = imaqCreateImage(IMAQ_IMAGE_RGB, 0);
	IMAQdxOpenCamera(CAMERA::CAM_ONE, IMAQdxCameraControlModeController, &session);
	Wait(.5);
	IMAQdxConfigureGrab(session);
	Wait(.5);
	IMAQdxStartAcquisition(session);
	Wait(.5);

	frame2 = imaqCreateImage(IMAQ_IMAGE_RGB, 0);

	mRobot = pRobot;
	mXbox = pXbox;
}

LHSVision::~LHSVision() //Destructor
{
	delete mXbox;
	delete mRobot;
}

//Used for closing and stopping acquisition of a camera
void LHSVision::StopCamera(int camNum)
{
	if(camNum == 1)	//Camera 1 Shutdown
	{
		IMAQdxStopAcquisition(session);
		Wait(.01);
		IMAQdxCloseCamera(session);
	}
	else			//Camera 2 Shutdown
	{
		IMAQdxStopAcquisition(session2);
		Wait(.01);
		IMAQdxCloseCamera(session2);
	}
}

//Used for opening, configuring, and starting acquisition of a camera
void LHSVision::StartCamera(int camNum)
{
	if(camNum == 1) //Camera 1 Startup
	{
		IMAQdxOpenCamera(CAMERA::CAM_ONE, IMAQdxCameraControlModeController, &session);
		Wait(.01);
		IMAQdxConfigureGrab(session);
		Wait(.01);
		IMAQdxStartAcquisition(session);
		Wait(.01);
	}
	else			//Camera 2 Startup
	{
		IMAQdxOpenCamera(CAMERA::CAM_TWO, IMAQdxCameraControlModeController, &session2);
		Wait(.01);
		IMAQdxConfigureGrab(session2);
		Wait(.01);
		IMAQdxStartAcquisition(session2);
		Wait(.01);
	}
}

//Send image to FRC PC Dashboard
void LHSVision::SendToDashboard(Image *image)
{
	CameraServer::GetInstance()->SetImage(image);
}

void LHSVision::UpdateVision() //by Michael
{
	if(mXbox->GetRawButton(XBOX::XBOX_A_BUTTON) == true)	//Toggle on A button press
	{
		while(mXbox->GetRawButton(XBOX::XBOX_A_BUTTON) == true)	//Prevents multi-press
		{}
		if(send == 1)
		{
			StopCamera(1);	//Stop Cam 1
			StartCamera(2);	//Start Cam 2
			printf("
Activating Camera 2 - Raw Image Display

");
			send = 2;
		}
		else
		{
			StopCamera(2);	//Stop Cam 2
			StartCamera(1);	//Start Cam 1
			printf("
Activating Camera 1 - Raw Image Display

");
			send = 1;
		}
	}

	if(send == 1)
	{
		IMAQdxGrab(session, frame, true, NULL);
		SendToDashboard(frame);		//Send Cam 1
		Wait(.1);
	}
	else
	{
		IMAQdxGrab(session2, frame2, true, NULL);
		SendToDashboard(frame2);	//Send Cam 2
		Wait(.1);
	}
}

Header File:

/*
 * LHSVision.h
 *
 *  Created on: Jan 25, 2016
 *      Author: Michael Conard
 */

#ifndef LHS_VISION_H
#define LHS_VISION_H

class RobotDrive;
class Joystick;

class LHSVision
{
public:
	LHSVision(RobotDrive*, Joystick*); //Constructor
	~LHSVision();	//Destructor
	void SendToDashboard(Image*); //Send Image to Dashboard
	void UpdateVision();	//Toggle and Display Camera
	void StopCamera(int);	//Close Specified Camera
	void StartCamera(int);	//Start Specified Camera

private:
	IMAQdxSession session;
	Image* frame;

	IMAQdxSession session2;
	Image* frame2;

	RobotDrive* mRobot;
	Joystick* mXbox;

	int send = 1;
};

#endif

My Main File:

/*
 * Robot.cpp
 *
 *  Created on: Jan 25, 2016
 *      Author: Michael Conard
 *
 *  This program requires:
 *  		-XBox Joystick
 *  		-Left Drive Talon
 *  		-Right Drive Talon
 *  		-Two USB Cameras on Roborio
 *  Ports can be adjusted below in PORTS namespace.
 *
 *  Controls:
 *  	-Forward/Reverse, Left Y Axis
 *  	-Rotating/Spinning, Left X Axis
 *  	-Toggling Front/Back Camera, A Button
 *
 *  Info: The cameras display to the FRC PC Dashboard.
 * 		  To open this: FRC Driver Station -> Third
 * 		  Tab (Setup) -> Set "Dashboard Type" to "Default"
 *
 * 		  In the FRC PC Dashboard near the bottom-middle,
 * 		  change "Camera Off" to "USB Camera HW".
 */

#include "WPILib.h"
#include "LHSVision.h"

namespace XBOX	//Joystick Constants
{
	const int NODE_ID = 1;

	const int XBOX_A_BUTTON  = 1;
	const int XBOX_X_BUTTON = 3;

	const int XBOX_LEFT_X = 0;
	const int XBOX_LEFT_Y = 1;
}

namespace PORTS	//Motor Constants
{
	const int LEFT_MOTOR = 0;
	const int RIGHT_MOTOR = 1;
}

class Robot: public SampleRobot
{
private:
	RobotDrive* mRobot;		//RobotDrive with two Talons
	Joystick* mStick;		//Joystick
	LHSVision* mLHSVision;	//Raw Image Display
public:
	Robot();				//Constructor
	~Robot();				//Destructor
	void OperatorControl();	//Can Drive and Toggle Cameras
	void Autonomous();		//No Content
};

Robot::Robot()	//Constructor
{
	printf("File %18s Date %s Time %s Object %p
",__FILE__,__DATE__, __TIME__, this);

	mRobot = new RobotDrive(PORTS::LEFT_MOTOR, PORTS::RIGHT_MOTOR);
	mStick = new Joystick(XBOX::NODE_ID);
	mLHSVision = new LHSVision(mRobot, mStick);	//LHSVision requires a RobotDrive and Joystick
}

Robot::~Robot()	//Destructor
{
	delete mRobot;
	delete mStick;
}

void Robot::OperatorControl()	//Driving and Camera Toggling
{
	while(IsOperatorControl() && IsEnabled())
	{
		mRobot->ArcadeDrive(mStick->GetRawAxis(XBOX::XBOX_LEFT_Y), mStick->GetRawAxis(XBOX::XBOX_LEFT_X));

		mLHSVision->UpdateVision();
		Wait(0.02);
	}
}

void Robot::Autonomous()	//No Content
{
	while(IsAutonomous() && IsEnabled())
	{
		printf("Autonomous!
");
	}
}

START_ROBOT_CLASS(Robot)

I hope this helps. If you need me to simplify my code structure to do only one USB camera let me know.

7

Put LCameraServer.cpp and LCameraServer.h in your project, and then use the LCameraServer class as you would CameraServer. Don’t use both at the same time (of course).

I would also recommend not using automatic capture. Grab your images using IMAQdx and call SetImage directly.

8