Programming the XRP
Writing a program for the XRP is very similar to writing a program for a regular FRC robot. In fact, all the same tools (Visual Studio Code, Driver Station, SmartDashboard, etc) can be used with the XRP.
Creating an XRP Program
Creating a new program for an XRP is like creating a normal FRC program, similar to the Zero To Robot programming steps.
WPILib comes with two templates for XRP projects, including one based on TimedRobot, and a Command-Based project template. Additionally, an example project is provided which showcases some of the built-in functionality of the XRP, and shows how to use the vendordep exposed XRP classes. This article will walk through creating a project from this example.
In order to program the XRP using C++, a compatible C++ desktop compiler must be installed. See Robot Simulation - Additional C++ Dependency.
Creating a New WPILib XRP Project
Bring up the Visual Studio Code command palette with Ctrl+Shift+P, and type “New project” into the prompt. Select the “Create a new project” command:
This will bring up the “New Project Creator Window”. From here, click on “Select a project type (Example or Template)”, and pick “Example” from the prompt that appears:
Next, a list of examples will appear. Scroll through the list to find the “XRP Reference” example:
Fill out the rest of the fields in the “New Project Creator” and click “Generate Project” to create the new robot project.
Running an XRP Program
Once the robot project is generated, it is essentially ready to run. The project has a pre-built
Drivetrain class and associated default command that lets you drive the XRP around using a joystick.
One aspect where an XRP project differs from a regular FRC robot project is that the code is not deployed directly to the XRP. Instead, an XRP project runs on your development computer and leverages the WPILib simulation framework to communicate with the XRP.
To run an XRP program, first, ensure that your XRP is powered on. Next, connect to
XRP-<IDENT> WiFi network broadcast by the XRP. If you changed the XRP network settings (for example, to connect it to your own network), you may change the IP address that your program uses to connect to the XRP. To do this, open the
build.gradle file and update the
wpi.sim.envVar line to the appropriate IP address.
43//Sets the XRP Client Host
45wpi.sim.addXRPClient().defaultEnabled = true
Now to start your XRP robot code, open the WPILib Command Palette (type Ctrl+Shift+P) and select “Simulate Robot Code”, or press F5.
If all goes well, you should see the simulation GUI pop up and see the gyro and accelerometer values updating.
Your XRP code is now running!