Get your robot

In Erebus, you design your robot: you choose its sensors and where they go, within a budget. Every program needs one, so the first step is to get a robot and load it in Erebus.

The robot is based on the e-puck, a small round educational robot with two wheels. You add sensors to it with the Robot Customizer, and save the design as a .json file that Erebus loads.

The starter robot

This documentation uses one robot everywhere, the starter robot, so that every example works as it is. It has all the sensors the tutorials need:

Component	Name in your program	What it is for
Two wheels	left wheel motor, right wheel motor	Moving
Wheel encoders	left wheel sensor, right wheel sensor	Measuring how far the wheels turned
Three distance sensors	leftDist, frontDist, rightDist	Finding walls on the left, in front and on the right
Camera, 64 × 40 pixels	camera	Finding wall tokens
Colour sensor	color	Seeing the floor: holes, swamps and passages
GPS	gps	Knowing its position, to report tokens
Gyro	gyro	Measuring how much it has turned
Accelerometer	accelerometer	Measuring acceleration
Lidar	lidar	Measuring distances all around
Emitter and receiver	emitter, receiver	Talking to the game. Every robot has them.

It costs 2400 of the budget of 3000.

Choose your path

Recommended: build it yourself. It takes about 15 minutes, and you will understand every part of your robot. Follow Build your robot.

In a hurry: download the finished robot and continue with the tutorials. You can always come back and build it later.

Download starter-robot.json

Load it in Erebus

1. Open a world, such as game/worlds/world1.wbt.
2. In the control window, press the right LOAD button, with the robot icon, and choose your .json file.
3. Check the Webots console. Erebus lists each component with its cost, and ends with Your custom robot has been successfully generated!.

Note

Erebus v26.1 also prints PROTO parameter 'camera_width' has no matching IS field in red. You can ignore it: your camera still has the resolution you chose.

The robot stays loaded until you load another one or reset the game. Next, run your first program.

Designing your own

Once you know the basics, change the starter robot or design a new one: more cameras with higher resolution, more distance sensors, sensors in other places. The Robot Customizer reference lists all the components, their costs and limits.

If you change the name of a component, change it in your program too.