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

2. 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

3. 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.

4. 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

5. 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:

6. 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

7. 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.

8. 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

9. 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:

10. 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.

11. 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: