encapsulation day 11 computer programming through robotics cpst 410 summer 2009
TRANSCRIPT
EncapsulationDay 11
Computer Programming through Robotics
CPST 410
Summer 2009
7/1/09 Harry Howard, CPST 410, Tulane University
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Course organization
Course home page (http://robolab.tulane.edu/CPST410/)
Lab (Newcomb 442) will be open for practice with 3-4 Macs, but you can bring your own laptop and all robots.
Encapsulation
My Blocks vs. Functions
My Blocks in NXT-GKelly §26 ‘My Block is your block’
Open the Mindstorms app.
7/1/09 Harry Howard, CPST 410, Tulane University
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A silly program
Tribot, do the following slowly (at 50% speed):Spin right for a rotation,and then show a happy face.Move forward for a second, and then beep.Spin left for a rotation,and then say “good job!”.
SillyProgram.rbt
7/1/09 Harry Howard, CPST 410, Tulane University
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Analysis
Note that the program really has three parts,but the structure of the program does not
show this division.There is a way to encapsulate each part into
its own block, called a My Block.
7/1/09 Harry Howard, CPST 410, Tulane University
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My Blocks
Select the first part (the first three blocks). Go to the Edit menu of the Mindstorms NXT application
and choose “Make a New My Block”. Give the block an informative name like StartUp and a short
explanation. Click the ‘Next’ button and choose a picture for it, such as one of
the motor icons. Click ‘Finish’.
You have just created your first MY BLOCK. It should have occupied the place of the originals in your
program, as shown in the next slide.
SillyProgram.rbt with StartUp
Keep on going
Note that if you double click on StartUp, it opens up in a new piece of graph paper, as if it were a program itself.
MY BLOCKS are stored in the Custom palette (aquamarine equals sign).
Now turn the other two pairs of blocks into My Blocks.
7/1/09 Harry Howard, CPST 410, Tulane University
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SillyProgram.rbt with MY BLOCKS
Functions in NXC
Close the Mindstorms app,
and open BricxCC.
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SillyProgram.nxctask main (){ OnFwdSync(OUT_BC, 50, 100); Wait(1000); Off(OUT_BC); GraphicOut(0, 0, "faceopen.ric"); Wait(500);
RotateMotor(OUT_BC, 50, 360); PlayTone(440, 500); Wait(500);
OnFwdSync(OUT_BC, 50, -100); Wait(1000); Off(OUT_BC); PlayFile("Good Job.rso"); Wait(700);}
7/1/09 Harry Howard, CPST 410, Tulane University
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Functions = My Blocksp. 149ff
Syntax: insert ‘void’ from Programreturn_type name(argument_list){
“statements”}
If there is no return type, use ‘void’.Define a function before the main task.
7/1/09 Harry Howard, CPST 410, Tulane University
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SillyProgram.nxc with one function
void StartUp(){ OnFwdSync(OUT_BC, 50, 100); Wait(1000); Off(OUT_BC); GraphicOut(0, 0, "faceopen.ric"); Wait(500);}task main(){
StartUp();RotateMotor(OUT_BC, 50, 360);PlayTone(440, 500);Wait(500);OnFwdSync(OUT_BC, 50, -100);Wait(1000);Off(OUT_BC);PlayFile("Good Job.rso");Wait(700);
}
7/1/09 Harry Howard, CPST 410, Tulane University
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SillyProgram.nxc with 3 functions
void StartUp(){ OnFwdSync(OUT_BC, 50, 100);
Wait(1000);Off(OUT_BC);GraphicOut(0, 0, "faceopen.ric");Wait(500);
}void ImportantStuff(){ RotateMotor(OUT_BC, 50, 360);
PlayTone(440, 500);Wait(500);
}void ShutDown(){ OnFwdSync(OUT_BC, 50, -100);
Wait(1000);Off(OUT_BC);PlayFile("Good Job.rso");Wait(700);
}task main(){
StartUp();ImportantStuff();ShutDown();
}
7/1/09 Harry Howard, CPST 410, Tulane University
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Next time
Parallelism.