# Beginners

The students developed a little game called EtchaSketch. This involves drawing on the EV3 display by turning two dials that control the coordinates of a dot that appears on the screen. The code works by taking the number of degrees that a motor is turned and turning that into X and Y coordinates that are then used in the display block to create a drawing. The students once again learned about concepts such as sequencing, loops, condition statements as well as concepts such as X and Y coordinates.

The code. The result. In this case the student modified the code to draw a circle instead of just a dot which had an interesting effect. Apologies for the upside down video, but it gives an idea about what is supposed to happen.

## Speed Trap

The advanced kids built a speed trap. This used two Ultrasonic sensors in order to detect when a car is in front of the sensor. It measured the time taken between the two sensors and then knowing the distance between the two sensors we calculated the speed of the car.  Speed = Distance / Time. So if the distance between the two sensors is 30 cm and it takes 2 seconds to cover that distance then the calculation is:

30cm / 2 seconds = 15 cm/seconds

Enhancements to the code that we did was to set a speed limit and to sound an alarm if the speed limit was exceeded. We also converted the cm/seconds unit into km/h. The code. Part 1 The code. Part 2 The result.