The Finch Robot and the While Loop

1. The Finch Robot and the While Loop Pepper

2. 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 • Will need to learn methods • May need to debug issues • Will it help you learn for the final?

3. Hardware • Input Sensors • Obstacles • Light • Accelerometer (how fast is it going) • Temperature • Output • Wheels turn • LED lights • Speaker • Power • Long USB Cord

4. Installing • Download Java package from http://www.finchrobot.com/Creating,%20Compiling,%20and%20Running%20Programs%20for%20Finch/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 • (or add jar file finch.jar to bluej via preferences Or add finch.jar to the +libs folder inside SourceFiles)

5. Make a Finch Controller • Bring in the knowledge: • import edu.cmu.ri.createlab.terk.robot.finch.Finch; • Create a finch object that knows finch commands: • Finch myFinch = new Finch(); • Always end with quit and exit: • myFinch.quit(); • System.exit(0);

6. Controlling commands • Set Finch Beak Color: • myFinch.setLED(red,green,blue); // 0 to 255 • Make Finch Speak: • myFinch.saySomething("The Finch will say this."); • Make Finch Move: • myFinch.setWheelVelocities(left,right,time)// -255 to 255 & time is in milliseconds // negative number rolls backwards // hold the cord or it may have difficulty

7. Simple program – • 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); • } • }

8. Get Finch Sense Information • Obstacles: All true/false • isObstacle() • isObstacleLeftSide() • isObstacleRightSide() • Light: All true/false, but using light level threshold. Returns true if less than the threshold • isRightLightSensor(10) • isLeftLightSensor(10) • 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”);}

9. 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);

10. Another - Make it do an action while a condition is true • 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

11. Do While • 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

12. Get orientation info • Orientation: All true/false • isFinchLevel() • isFinchUpsideDown() • isBeakDown() • isBeakUp() • isLeftWingDown() • isRightWingDown()

13. 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

14. Your Turn • Probably not needed, but see finch.jar in preferences • Download java finch package • http://www.finchrobot.com/Creating,%20Compiling,%20and%20Running%20Programs%20for%20Finch/bluej • New class • Import above class: • import edu.cmu.ri.createlab.terk.robot.finch.Finch; • Inside main method, create a finch object • Finch myFinch = new Finch(); • Close your finch at the end of main • myFinch.quit(); • System.exit(0); • Add code to make it move right and test. • Then make it do something until it hits a wall.