Selection Learning Objective: to be able to design algorithms that use selection.

Right Motor Forward Off Selection With selection different sets of instructions are executed depending on the result of a condition. Here is an example of an algorithm that uses selection: Start Right Motor Forward On Left Motor Forward Off Left Motor Forward On Right Motor Forward Off Button A Pressed? Button B Pressed? Yes No LOOP IF ButtonA.pressed THEN RightMotor.forward(off) LeftMotor.forward(on) ELSEIF ButtonB.pressed THEN LeftMotor.forward(off) RightMotor.forward(on) ENDIF ENDLOOP

Predict what this program will do: Activity 1 Here is the program code for the algorithm given on the previous slide. Predict what this program will do: Prediction: Now write this program and test it on Bobbot.

Activity 2 LOOP IF ButtonA.pressed THEN ELIF ButtonB.pressed THEN Design an algorithm in pseudocode that makes Bobbot move in different patterns of your choice when buttons A and B are pressed. LOOP IF ButtonA.pressed THEN ELIF ButtonB.pressed THEN ENDIF ENDLOOP

Place a screenshot of your code here: Activity 3 Use Touch Develop to create the program you designed in activity 2 and test it on Bobbot. Place a screenshot of your code here:

Line Sensor Bobbot is fitted with a line sensor that can be used to detect whether the surface it over is light or dark. The line sensor is connected to pin 1. LOOP IF LineSensor.light THEN Display(“L”) ELSE Display(“D”) ENDIF ENDLOOP

Predict what this program will do: Activity 4 Here is the program code for the algorithm given on the previous slide. Predict what this program will do: Prediction: Now write this program and test it on Bobbot.

Activity 5 LOOP IF LineSensor.light THEN ELSE ENDIF ENDLOOP Design an algorithm in pseudocode that makes Bobbot follow a dark line by turning right if it is over a light surface and turning left if it is over a dark surface. LOOP IF LineSensor.light THEN ELSE ENDIF ENDLOOP

Place a screenshot of your code here: Activity 6 Use Touch Develop to create the program you designed in activity 5 and test it on Bobbot. It should make Bobbot follow a dark line. Place a screenshot of your code here:

Extension (Part A) Design an algorithm that will make Bobbot move in a zig zag pattern if button A is pressed and follow a line if button B is pressed.

Place a screenshot of your code here: Extension (Part B) Use Touch Develop to create the program you designed on the previous slide and test it on Bobbot. Place a screenshot of your code here: