More switches Day 6 Computer Programming through Robotics CPST 410 Summer 2009

7/1/09Harry Howard, CPST 410, Tulane University2 Course organization  Course home page Course home page  (  Lab (Newcomb 442) will be open for practice with 3-4 Macs, but you can bring your own laptop and all robots.

Stop it Kelly §13

7/1/09Harry Howard, CPST 410, Tulane University4 The STOP block  The STOP block, in the Complete palette under the Flow icon, stops a program from continuing.  It is a good way to break out of loops.  Tribot, beep until the Touch sensor is pressed.

7/1/09Harry Howard, CPST 410, Tulane University5 Stop.rbt

7/1/09Harry Howard, CPST 410, Tulane University6 The NXC analog  NXC has a constant ‘break’ that breaks a loop whenever it is encountered in a program.  How would you formulate the previous program for NXC?  First you need an endless loop.

7/1/09Harry Howard, CPST 410, Tulane University7 The endless loop task main() { while (true) { // statements here }

7/1/09Harry Howard, CPST 410, Tulane University8 Stop.nxc first version task main() { while (true) { PlayTone(440,500); Wait(500); if (Sensor(S1) ????) { break; }

7/1/09Harry Howard, CPST 410, Tulane University9 Stop.nxc final version task main() { SetSensorMode(S1, SENSOR_MODE_PERCENT); while (true) { PlayTone(440,500); Wait(500); if (Sensor(S1) < 98) // unpressed = 100! { break; }

7/1/09Harry Howard, CPST 410, Tulane University10 Protect your robot  Tribot, move forward until the Touch sensor is released.

7/1/09Harry Howard, CPST 410, Tulane University11 TouchStop.rbt

Pick a card, any card Kelly §12

7/1/09Harry Howard, CPST 410, Tulane University13 The RANDOM block  In the Complete palette under the Data icon.  It generates a number between 0 and 100, randomly.

7/1/09Harry Howard, CPST 410, Tulane University14 Display a random number  Tribot, display a random number between 20 and 80 every time the left NXT button is pressed and then beep, until the right button is pressed.

7/1/09Harry Howard, CPST 410, Tulane University15 DisplayRandom.rbt

7/1/09Harry Howard, CPST 410, Tulane University16 Random numbers in NXC  Random()  Returns a single number chosen randomly between 0 and 2 16 or 65,536.  Random(n)  Returns a single number chosen randomly between 0 and n-1.

7/1/09Harry Howard, CPST 410, Tulane University17 Display a random number in NXC

7/1/09Harry Howard, CPST 410, Tulane University18 More than two choices  SPOT, when I press the left NXT button, pick a number from 1 to 3. If the number is 1, display an image. If the number is 2, beep. If the number is 3, play a sound.  Drag out a SWITCH block and turn off Flat view  Control > Value  Type > Number  Conditions  1. > 1  2. > 2  + 3. > 3

7/1/09Harry Howard, CPST 410, Tulane University19 Switch3.rbt

7/1/09Harry Howard, CPST 410, Tulane University20 Next time  P2  Multiple switches in NXC.  Comparison: Kelly §15.  The RANGE and LOGIC blocks: Kelly §16-17.