Network Tables?

[charrisTTI]

NetworkTable object can be used to pass data to/from robot code and another program running on another computer on the network. SmartDashboard uses it to pass data to/from robot.

We use it to pass data from image processing software running on the driver station back to the robot.

Here is example code:

//========================================
//Robot Code
// declare object
NetworkTable cameraTable;

// getinstance (table is a singleton, if one does not exist then one will
// be created otherwise returns reference to existing instance
cameraTable = NetworkTable.getTable("camera");

// get data element from the table
// default values returned if no data has been provided from another source yet

cameraTable.beginTransaction();
Boolean imageFound = cameraTable.getBoolean("found", false );
Double imageOffset = cameraTable.getDouble("offset", -1.0);
Double imageDistance = cameraTable.getDouble("distance", -1.0);
cameraTable.endTransaction();

System.out.println( "found = " + imageFound);
System.out.println( "offset = " + imageOffset);
System.out.println( "distance = " + imageDistance);

//=======================================
// Driver Station PC
// camera image processing is done in C# application on DS

// declare it
private NetworkTable table;

// Init NetworkTable
NetworkTable.setIPAddress("10.6.23.2");  // ip of crio
table = NetworkTable.getTable("camera");


// in the image processing loop

table.beginTransaction();
table.putBoolean("found", true);
table.putDouble("distance", distance);
table.putDouble("offset", offset);
table.endTransaction();