THE FINCH ROBOT
AND THE WHILE LOOP
Pepper
THE ROBOT
Developed by Carnegie Mellon students to teach CS
 Supports many compilers, including Java
 Web site: http://www.finchrobot.com/
 Why – Illustrate while and do /while loops with
physical example
 Why 2: See how hardware and physical actions can be
controlled with code
 Lab group practice
 Extra: One robot available for creating game
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Will need to learn methods
 May need to debug issues
 Will it help you learn for the final?
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HARDWARE
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Input Sensors
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Obstacles
Light
Accelerometer
(how fast is it
going)
Temperature
Output
Wheels turn
 LED lights
 Speaker
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Power
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Long USB Cord
INSTALLING
Download Java package from
http://www.finchrobot.com/Creating,%20Compili
ng,%20and%20Running%20Programs%20for%20
Finch/bluej
 Place it in the folder you want to use
 Unzip it
 Open sample project in sourceFiles bluej.pkg
 Create your own package inside sample project
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(or add jar file finch.jar to bluej via preferences Or
add finch.jar to the +libs folder inside SourceFiles)
MAKE A FINCH CONTROLLER
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Bring in the knowledge:
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Create a finch object that knows finch commands:
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import edu.cmu.ri.createlab.terk.robot.finch.Finch;
Finch myFinch = new Finch();
Always end with quit and exit:
myFinch.quit();
 System.exit(0);
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CONTROLLING COMMANDS
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Set Finch Beak Color:
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Make Finch Speak:
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myFinch.setLED(red,green,blue); // 0 to 255
myFinch.saySomething("The Finch will say this.");
Make Finch Move:
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myFinch.setWheelVelocities(left,right,time)
// -255 to 255 & time is in milliseconds
// negative number rolls backwards
// hold the cord or it may have difficulty
SIMPLE PROGRAM –
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package Pepper;
import edu.cmu.ri.createlab.terk.robot.finch.Finch;
public class FinchSimple {
public static void main(final String[] args) {
// Instantiating the Finch object
Finch myFinch = new Finch();
myFinch.setWheelVelocities(255,255,1000);
myFinch.saySomething(“I am now All Done");
// Always end your program
myFinch.quit();
System.exit(0);
}
}
GET FINCH SENSE INFORMATION
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Obstacles: All true/false
isObstacle()
 isObstacleLeftSide()
 isObstacleRightSide()
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Light: All true/false, but using light level
threshold. Returns true if less than the threshold
isRightLightSensor(10)
 isLeftLightSensor(10)
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In dark, it will be true up to about 4
 In light, it will be true up to about 40
 Ex: if (myFinch.isRightLightSensor(10) == true)
{ System.out.println(“It is light out”);}
else {System.out.println(“It is dark out”);}
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MAKE IT DO AN ACTION WHILE A
CONDITION IS TRUE
Keep moving forward until it senses an obstacle
while ( myFinch.isObstacle() == false ){
myFinch.setWheelVelocities(255,255,200);
}
// then back up
myFinch.setWheelVelocities(-255,-255,1000);
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ANOTHER - MAKE IT DO AN ACTION WHILE
A CONDITION IS TRUE
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Spin until the lights turn off
while (myFinch.isRightLightSensor(10) == true){
myFinch.setWheelVelocities(255,-255,1000);
}
// when the lights are out, this will be false
// when the lights are on, this will be true
// could say spin while lights are on
// WILL NOT SPIN AT ALL IF LIGHTS OFF
DO WHILE
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Spin at least once, and then keep spinning until
the lights turn off
do
{ myFinch.setWheelVelocities(255,-255,1000);
}
while (myFinch.isRightLightSensor(10) ==
true);
// run with lights off – see one spin first
GET ORIENTATION INFO
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Orientation: All true/false
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isFinchLevel()
isFinchUpsideDown()
isBeakDown()
isBeakUp()
isLeftWingDown()
isRightWingDown()
YOUR TAKEAWAY
Difference between while and do while
 Creating an object of a class gives your program
powerful tools
 A sense of how hardware can be controlled by
code
 Perhaps a desire to code your game using this
little robot
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YOUR TURN
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Probably not needed, but see finch.jar in preferences
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Download java finch package
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New class
Import above class:
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import edu.cmu.ri.createlab.terk.robot.finch.Finch;
Inside main method, create a finch object
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http://www.finchrobot.com/Creating,%20Compiling,%20and%2
0Running%20Programs%20for%20Finch/bluej
Finch myFinch = new Finch();
Close your finch at the end of main
myFinch.quit();
 System.exit(0);
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Add code to make it move right and test.
Then make it do something until it hits a wall.