My dashboard would not show the color for my color sensor, please help me

package frc.robot;

import edu.wpi.first.wpilibj.TimedRobot;

import edu.wpi.first.wpilibj.I2C.Port;

import edu.wpi.first.wpilibj.smartdashboard.SmartDashboard;

import edu.wpi.first.wpilibj.util.Color;

import com.revrobotics.ColorMatchResult;

import com.revrobotics.ColorSensorV3;

import com.revrobotics.ColorMatch;

import edu.wpi.first.wpilibj.smartdashboard.SendableChooser;


  • The VM is configured to automatically run this class, and to call the

  • functions corresponding to each mode, as described in the TimedRobot

  • documentation. If you change the name of this class or the package after

  • creating this project, you must also update the build.gradle file in the

  • project.


final public class Robot extends TimedRobot {

private static final String kDefaultAuto = “Default”;

private static final String kCustomAuto = “My Auto”;

private String m_autoSelected;

private final SendableChooser m_chooser = new SendableChooser<>();

private Port i2cPort;


  • This function is run when the robot is first started up and should be

  • used for any initialization code.



final public void robotInit() {

m_chooser.setDefaultOption("Default Auto", kDefaultAuto);

m_chooser.addOption("My Auto", kCustomAuto);

SmartDashboard.putData("Auto choices", m_chooser);



final public void teleopPeriodic() {

ColorMatchResult match = m_colorMatcher.matchClosestColor(detectedColor);




SmartDashboard.putNumber("Confidence", match.confidence);

SmartDashboard.putString("Detected Color", colorString);



  • This function is called every robot packet, no matter the mode. Use

  • this for items like diagnostics that you want ran during disabled,

  • autonomous, teleoperated and test.

  • This runs after the mode specific periodic functions, but before

  • LiveWindow and SmartDashboard integrated updating.


private final ColorMatch m_colorMatcher = new ColorMatch();

private final ColorSensorV3 m_colorSensor = new ColorSensorV3(i2cPort);

Color detectedColor = m_colorSensor.getColor();

String colorString;


final public void robotPeriodic() {



  • This autonomous (along with the chooser code above) shows how to select

  • between different autonomous modes using the dashboard. The sendable

  • chooser code works with the Java SmartDashboard. If you prefer the

  • LabVIEW Dashboard, remove all of the chooser code and uncomment the

  • getString line to get the auto name from the text box below the Gyro

  • You can add additional auto modes by adding additional comparisons to

  • the switch structure below with additional strings. If using the

  • SendableChooser make sure to add them to the chooser code above as well.



public void autonomousInit() {

m_autoSelected = m_chooser.getSelected();

// m_autoSelected = SmartDashboard.getString("Auto Selector", kDefaultAuto);

System.out.println("Auto selected: " + m_autoSelected);



  • This function is called periodically during autonomous.


  • This function is called periodically during operator control.



You’re not actually creating the port. The line Port i2cPort; should be more like Port i2cPort = I2C.Port.kOnboard;. I hope this helps!

Note: your post looks better when you format your code by surrounding it with backticks :wink:

thanks for the help but its not working

Ah, I see the problem. You need to do two things:

  1. Change this import: edu.wpi.first.wpilibj.I2C.Port to this: edu.wpi.first.wpilibj.I2C
  2. Change private Port i2cPort = I2C.Port.kOnboard; to private I2C.Port i2cPort = I2C.Port.kOnboard;

Thank you for the screenshot!

thanks but this still show up in my screen. * Could not instantiate robot edu.wpi.first.wpilibj.I2C!

  • at edu.wpi.first.wpilibj.RobotBase.runRobot(

  • at edu.wpi.first.wpilibj.RobotBase.startRobot(

  • at frc.robot.Main.main(

  • Warning at edu.wpi.first.wpilibj.RobotBase.runRobot( Robots should not quit, but yours did!

  • Error at edu.wpi.first.wpilibj.RobotBase.runRobot( Could not instantiate robot edu.wpi.first.wpilibj.I2C!

  • ********** Robot program starting **********

  • ********** Robot program starting **********

  • ********** Robot program starting **********

If there aren’t any red lines in your code, it’s probably that the I2C port is already in use.
Is this a blank color-sensor-only program, or a full robot program?

If you put your code on github and post a link you can get better help.

Does the code build?

The error they’re getting suggests that the code builds, but fails to run on the roboRIO.

Agreed with @NewtonCrosby. Please post your code in github or similar so we can look at it.

Also, please post the error you’re currently getting.

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