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

Hardware Input Sensors Output Power Obstacles Light Accelerometer (how fast is it going) Temperature Output Wheels turn LED lights Speaker Power 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 (or add jar file finch.jar to bluej via preferences Or add finch.jar to the +libs folder inside SourceFiles)

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);

Controlling commands Set Finch Beak Color: Make Finch Speak: 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

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); }

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”);}

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);

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

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

Get orientation info Orientation: All true/false 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

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 forward, backward, right and left, all for one second each.