Limelight not working

Technical Sensors
1

Out team purchased a limelight sensor last year and it worked great. This year I upgraded the limelight version 1 to the 2019.2 software. and after updating the code deploys to robot but when I activate the limelight nothing occurs. help would be appreciated here is the code.

void limelightAim()
{
float left_command = 0;
float right_command = 0;

	float KpAim = 0.0125;
	float KpDist = 0.08;
	float min_command = 0.05f;
	float min_commandY = 0.05f;

	std::shared_ptr<NetworkTable> table = NetworkTable::GetTable("limelight");

	double targetX = table->GetNumber("tx", 0.0);
	double targetY = table->GetNumber("ty", 0.0);
	double targetA = table->GetNumber("ta", 0.0);

	double heading_error = targetX;
	double distance_error = targetY;

	double steering_adjust = KpAim * heading_error;
    double driving_adjust = KpDist * distance_error;

	if (targetX > 0.1f)
	{
		steering_adjust += min_command;
		//led->Set(0.77);
		//rightMotors(0.3);
		//leftMotors(-0.3);
	}
	else if (targetX < -0.1f)
	{}
		steering_adjust -= min_command;
		//led->Set(0.77);
		//rightMotors(-0.3);
		//leftMotors(0.3);
	}
	else if (targetY < 6.0f)
	{
		driving_adjust += min_commandY;
		//led->Set(0.77);
		//rightMotors(0.3);
		//leftMotors(0.35);
	}




	if (targetA == true)
	{
		led->Set(-0.57);
	}
	else
	{
		led->Set(0.73);
	}

	//left_command = left_command + steering_adjust - driving_adjust;
	//right_command = right_command - steering_adjust - driving_adjust;
	//StandardTank(left_command,right_command);

	frc::SmartDashboard::PutNumber("Target X Values", targetX);
	frc::SmartDashboard::PutNumber("Target Y Value", targetY);
}
2

First, I would check if you are getting comms with Limelight. You can do so by checking the configuration page (limelight.local:5801) and confirming that targeting data is being published to NetworkTables by opening Shuffleboard (./gradlew shuffleboard or gradlew.bat shuffleboard), click the arrow on the left to expand the sidebar, and seeing if the limelight table exists under the NetworkTables section and has values under it.

3

Yes we are. Has the code perhaps changed or something declared differently. Because it was perfectly normal before flashing the 2019.2. It was only after that it became dissfucntional.

4

Flashing may have changed your team number and set you up to a dynamic IP. What worked for me was to connect via phone to the robot, pull up limelight.local:5801, and then adjust to a static IP and set your team number. You can then reach it on your computer through 10.TE.AM.85

5

My team is having similar issues, though we don’t know if an update is what caused it. Essentially, Shuffleboard correctly displays the limelight NetworkTable with live values, but when we try to read values from it using the sample code form the limelight documentation, it fails to access the correct NetworkTable.

I tried writing values to the limelight NetworkTable instead, which resulted in something very odd. A duplicate limelight NetworkTable appeared in Shuffleboard with only one entry under it: the entry I had written.

The static IP is correctly set and all, so we have no idea what’s going on.

6

Every time you update the Limelight software, you need to reconfigure the network settings.
Follow the networking steps in the Limelight documentation: http://docs.limelightvision.io/en/latest/getting_started.html#networking-setup

An addendum I would add is that if you have the Bonjour drivers and you still do not see the limelight, a reinstall of the drivers and then a restart of your computer can fix the connectivity issues. Once you’ve put the limelight back into a static IP, you should have no more issues connecting to it when its on the robot.

7

Are you on 2019.3? Have you changed the LL hostname?

8

I’m on 2019.3, and I can access the limelight dashboard no problem at 10.TE.AM.11:5801. The hostname is still the default hostname “limelight” with nothing else.

Shuffleboard can actually see the entire table properly, but both a desktop client and the roboRIO cannot access the table correctly.

9

If you use outline viewer with the code that you wrote to the table, it may show you what’s different between the table that the limelight is writing to vs what your code wrote to.

10

Could you link me to how this “outline viewer” works? Thanks

Also, what could possibly be different?

11

Here is a link to the screensteps that explain the outline viewer. To open it in VSCode, hit the three dots in the top right (near the WPILib icon) and hit “Start Tool”. Then select “OutlineViewer” from the popup.

I’m not sure what would be different from last year, as far as I could tell everything I wrote last year worked the same for me.

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