Programming the Romi

Writing a program for the Romi 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 Romi.

Creating a Romi Program

Creating a new program for a Romi is like creating a normal FRC program, similar to the Zero To Robot programming steps.

WPILib comes with two templates for Romi 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 Romi. This article will walk through creating a project from this example.


In order to program the Romi using C++, a compatible C++ desktop compiler must be installed. See Robot Simulation - Additional C++ Dependency.

Creating a New WPILib Romi 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 “RomiReference” example:


Fill out the rest of the fields in the “New Project Creator” and click “Generate Project” to create the new robot project.

Running a Romi 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 Romi around using a joystick.

One aspect where a Romi project differs from a regular FRC robot project is that the code is not deployed directly to the Romi. Instead, a Romi project runs on your development computer and leverages the WPILib simulation framework to communicate with the Romi robot.

To run a Romi program, first, ensure that your Romi is powered on. Next, connect to the WPILibPi-<number> WiFi network broadcast by the Romi. If you changed the Romi network settings (for example, to connect it to your own WiFi network) you may change the IP address that your program uses to connect to the Romi. To do this, open the build.gradle file and update the wpi.sim.envVar line to the appropriate IP address.

43//Sets the websocket client remote host.
44wpi.sim.envVar("HALSIMWS_HOST", "")
45wpi.sim.addWebsocketsServer().defaultEnabled = true
46wpi.sim.addWebsocketsClient().defaultEnabled = true

Now to start your Romi robot code, open the WPILib Command Palette (type Ctrl+Shift+P) and select “Simulate Robot Code”, or press F5.

Launching simulation via the WPILib Command Palette

If all goes well, you should see a line in the console output that reads “HALSimWS: WebSocket Connected”:


Your Romi code is now running!