The robot is imagined as the centre of this display. The front of the robot is always towards the top of the screen, whatever direction the robot is actually facing. The remote user drives the robot by means of the four cursor-control keys on the user's keyboard, with the arrows having the obvious significance of 'left, right, forward, reverse'. Press the space-bar, or enter, to stop the robot's motors. The robot may be guided visually by the user, using the vidcon picture.
Sonars operate as a cone, and are fixed on the robot.
The bearing given is the centre line, and the range returned is the distance to the closest obstacle anywhere in that cone. The display should be seen as an indication that there is an obtacle somewhere in that general direction, not a precise location of an obstacle. Sonars can give varying readings, and may appear to jump in and out occasionally. If an obstacle is suddenly not detected, for example if it is moved away, or it moves out of the cone of a particular sensor, the robot will stop receiving an echo time for that sensor. Since this could also be due to a fault, the robot slowly increments the range counter.