These blocks work for both EV3 Robot and Ruby Robot!
The Gadgets menu contains three trail blocks, which enable your robot to leave a trail behind it and draw geometric shapes or create beautiful artwork. This also be can be useful for debugging your code.
Note: in the Cyber Robotics 101 course, the trail blocks appear in the Utilities menu.
Drag a 'start trail' block into your code and choose its color from the menu.
If the robot is configured with more than one trail drawer, they will appear in the drop-down menu of the block and you can choose which trail to operate in each block: