SECOND VERSION
The aim of the activity is to detect and compare the distance between a person and a screen by programming the ultrasonic sensor. There will occur two different responses to a short approach: the mBot will perform light and sound effects while the screen will show a message and end the running game.
The activity will be developed as follows:
- A student has created a videogame using scratch and now is playing with it.
 - Little by little, this student approaches to the screen. If he/she arrives to a distance between 40 and 25 cm to the screen, the mBot will warn about this short distance by performing "First Warning” routine.
 - If the student ignores the first warning and approaching to the screen (to a distance smaller than 25 cm), the mBot will warn about it by performing "Final Warning” routine and stopping the game.
 
This Final Warning will contain:
- Sound and light effects performed in a higher tone and speed.
 - An angry face showed in the LED matrix.
 - The following warning messages appearing on the laptop screen: "You are TOO CLOSE to the screen” MOVE BACK!!”.
 - A change of scenario for the game.