- FRC Game Manual
- FRC Game Q&A

# Sending data

Unlike SmartDashboard, data cannot be sent directly to Shuffleboard without first specifying what tab the data should be placed in.

## Sending simple data

Sending simple data (numbers, strings, booleans, and arrays of these) is done by calling `add` on a tab. This method will set the value if not already present, but will not overwrite an existing value.

JAVA

    Shuffleboard.getTab("Numbers")
         .add("Pi", 3.14);

C++

    frc::Shuffleboard::GetTab("Numbers")
         .Add("Pi", 3.14);

PYTHON

    from wpilib.shuffleboard import Shuffleboard
    Shuffleboard.getTab("Tab Title").add("Pi", 3.14)

If data needs to be updated (for example, the output of some calculation done on the robot), call `getEntry()` after defining the value, then update it when needed or in a `periodic` function

JAVA

    class VisionCalculator {
       private ShuffleboardTab tab = Shuffleboard.getTab("Vision");
       private GenericEntry distanceEntry =
          tab.add("Distance to target", 0)
             .getEntry();
       public void calculate() {
          double distance = ...;
          distanceEntry.setDouble(distance);
       }
    }

PYTHON

    from wpilib.shuffleboard import Shuffleboard
    def robotInit(self):
       tab = Shuffleboard.getTab("Vision")
       self.distanceEntry = tab.add("Distance to target", 0).getEntry()
    def teleopPeriodic(self):
       distance = self.encoder.getDistance()
       self.distanceEntry.setDouble(distance)

## Making choices persist between reboots

When configuring a robot from the dashboard, some settings may want to persist between robot or driverstation reboots instead of having drivers remember (or forget) to configure the settings before each match.

Simply using addPersistent instead of add will make the value saved on the roboRIO and loaded when the robot program starts.

Note

This does not apply to sendable data such as choosers or motor controllers.

JAVA

    Shuffleboard.getTab("Drive")
         .addPersistent("Max Speed", 1.0);

C++

    frc::Shuffleboard::GetTab("Drive")
         .AddPersistent("Max Speed", 1.0);

PYTHON

    from wpilib.shuffleboard import Shuffleboard
    (Shuffleboard.getTab("Drive")
          .addPersistent("Max Speed", 1.0))

## Sending sensors, motors, etc

Analogous to `SmartDashboard.putData`, any `Sendable` object (most sensors, motor controllers, and SendableChoosers) can be added to any tab

JAVA

    Shuffleboard.getTab("Tab Title")
         .add("Sendable Title", mySendable);

C++

    frc::Shuffleboard::GetTab("Tab Title")
         .Add("Sendable Title", mySendable);

PYTHON

    from wpilib.shuffleboard import Shuffleboard
    (Shuffleboard.getTab("Tab Title")
          .add("Sendable Title", mySendable))