1. Group Four Catherine Fahey, Steven Falzerano, Nicollette Fernandez, Eliot M. Fine and Stefan Toubia

2. Los Jefes Darth Vader

3. Objective To create a robot that follows a course laid out in black tape, make a u-turn, and return to the starting line following the tape again. In doing so, we can learn more about Interactive C programming and the Handyboard.

4. Resources  Handyboard  2 motors  2 analog light sensors,  Lego's (this includes treads, wheels, and gears)

5. Procedure:  We chose: Treads: because the robot was able to make the adjustments more easily, and also the robot got more traction Gears: because the motors were too weak to actually move the robot Our trial-and-error process helped us come to these conclusions.

6. Code void main(){ int lap; lap=0; while(start_button()==0){} while(1){ if(analog(5)<200 && analog(6)<200){ motor(1,100); motor(3,100); // if the light sensors read white then both motors go forward at a speed of 20 } else if(analog(5)>=200 && analog(6)<200){ motor(1,-100); motor(3,100); // but if analog 5 reads dark (the black tape), then the robot will turn right } else if(analog(5) =200){ motor(1,100); motor(3,-100); //but if analog 6 read dark, then the robot will turn left } else if(lap==0 && analog(5)>=200 && analog (6)>=200){ motor(1,-100); motor(3,100); sleep(1.5); //the robot reads dark, then the robot will make a u-turn and head to the start line while(analog(5)<200{}; lap ++; //new lap, repeats above but goes to next statement when reaches start line } else{ ao();// robot turns off once at start line again }

8. Challenges:  Friction Our original design (3 wheels: 2 with tires, 1 without), did not pick up enough friction Our original design (3 wheels: 2 with tires, 1 without), did not pick up enough friction Switched to treads Switched to treads ○ Motors were too weak, so we had to add gears to help give more force

10. What is a Centrifuge?  A piece of equipment that rotates about an axis  Uses centrifugal forces to separate substances Heaviest molecules move to the bottom of the tube  Used in biology, chemistry, and aeronautics Separate substances Meselson and Stahl experiment

11. Set Up  Used: IR “Top-Hat” sensor, scotch tape and a cuvette, gears, wheels  Constructed: Base of legos Motor with gears to create an axel T-shaped crossbar attached to the axel One side had a cuvette the other had a counterweight Tires attached to base to act as shock absorbers and supports *Note: need white paper behind cuvette

12. die Windmühle

13. Code void main(){ int speed=0; float separation_time=5.0;// Time, seconds, that centrifuge will spin float ramp_time=0.1;// Time, seconds, between speeds printf ("\nHold Down Start Button to Take Readings"); while (start_button()==0) {} while (start_button()==1) {// Top-Hat reads while button is pressed printf ("\nAmount mixed is %d", analog(3)); sleep (0.2); } while (speed<=100) {// Speed gradually increases from 0 to 100 printf ("\nSpeed is %d",speed); motor (1,speed); sleep (ramp_time); speed++; } sleep (separation_time);// Centrifuge spins for specified time at 100 while (speed>0) {// Speed gradually decreases from 100 to 0 printf ("\nSpeed is %d",speed); motor (1,speed); sleep (ramp_time); speed--; } ao(); while (speed==0) {// Everthing shuts off and Top-Hat reads again printf ("\nMixation = %d, Did they separate?”,analog(3)); sleep (0.2); } http://tinypic.com/player.php?v=34njo6s&s=4

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15. Conclusions  We learned: ○ From the Robot: ○ Treads are slower but they have more traction ○ Going from big gears to small gears increases speed and from small gears to big gears increases torque ○ A sturdy frame is crucial Improvements: ○ Our code could have had a slower, more careful turn, so that it would not whip around Improvements with the centrifuge: ○ Faster motors, more durable parts, more easily- removable cuvettes, a built-in IR sensor ○ The code did work extremely well though