Launcher Programming Guide (ROBOTC - TETRIX … · Note: A comment is not part of the code that the...

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Introduction:

Inthisguide,theRangerBotwillbeprogrammedtofollowalinewhilecarryingaball.Uponsensingabinwithitsultrasonicsensor,itwilllaunchtheballintothebin.ThisguideisforusewiththeROBOTC®programminglanguage.

Getting Started:

1.Tostarttheprogram,typethe Main Taskfunctionfollowedbyanopening brace.

taskmain()

{

2.Declarethreeinteger variables asseeninthecodebelow.Besideeachvariable,therearetwoslashes(//)followedbywhatthatvariableisrepresenting.Thesemarkacomment.NoticethatcommentsappeargreenwhencodeistypedintoROBOTC.

Note:AcommentisnotpartofthecodethattheNXTBrickwillexecute,butithelpstheprogrammerbyallowingtheadditionofnotestodescribewhathasbeendone.

intnValue; //lightsensorvalue

intmValue; //sonarsensorvalue

intPosition; //servoarmposition

3.TypetheWait functionandsetittowait 50 millisecondstoallowtherobottoinitializemotorsandsensors.

wait1Msec(50);

4.Typethe servo position commandtoinitializethepositionoftheservo.Thismustbesettoavaluebetween0and255,representingapositionbetween0°and180°,theservo’sfullrangeofmotion.

servo[servo1]=128;

5.AddaWhile Looptowaituntilthetouchsensorhasbeentouchedinorderfor motorDand motorE tostartmoving.Ifthetouchsensorhasbeenpressedthenthevalueofthetouchsensor,atthatmoment,wouldbe1;otherwise,thevalueofthetouchsensorwillbezero.Thus,theconditionfortheWhile LoopstatementwouldbetocheckifthetouchsensorvalueisequaltozeroinordertosetbothmotorDandmotorEtoavalueofzero.

while(SensorValue[Touch]==0)

{

motor[motorE]=0;

motor[motorD]=0;

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6.Setthedefinedvariablestoavalueanddisplaythemtothescreen.

a.SetthenValuevariabletothevalueofthelightsensor,andthemValuevariabletothevalueoftheultrasonicsensor.

b.UsetheNXTwritetoscreencommandtoputthemonthescreen.

Thewritetoscreencommandrequiresthreepiecesofinformation,calledparameters,inordertowritebothtextandavariabletothescreen:

i.Thelinenumber.

ii.Thetext(inquotations)thatincludesadisplayvariablecaller.

Note:Inthiscase,%disthedisplayvariablecaller.Intheplaceof%d,anintegervariableisdisplayedonthe`screen.

iii.Thevariablename.

Thisinformationisinsidethebracketsbesidethecommand,separatedbycommas.

nValue=SensorValue[LightSensor];

nxtDisplayTextLine(0,"LightValue:%d",nValue);

mValue=SensorValue[SonarSensor];

nxtDisplayTextLine(2,"SonarValue:%d",mValue);

7.Belowthetextthatwasjustwrittentothescreen,displayamessagethatsays“START: Press Touch.”Becausenovariablewillbedisplayed,onlytwoparametersneedtobesenttothefunction,thelinenumberandthetext.

nxtDisplayCenteredTextLine(4,"START:PressTouch");

8.Typeaclosing bracetoendtheWhileLoopinstep5.

}

9.Addaninfinite While Looptomakethecontainingcodeexecuteforever.

while(true)

{

10.Initializeboththemotorsthataremovingthetires,whicharemotorAandmotorB,tobeequaltozerousingtheMotorfunction.

motor[motorA]=0;

motor[motorB]=0;

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11.Next,setthedefinedvariablestoavalueanddisplaythemtothescreen.SetthenValuevariabletothevalueofthelightsensorandthemValuevariabletothevalueoftheultrasonicsensor.UsetheNXTwritetoscreencommandtoputthemonthescreen.ThisissimilartothecodethatwastypedinStep 6.

nValue=SensorValue[LightSensor];

nxtDisplayTextLine(0,"LightValue:%d",nValue);

mValue=SensorValue[SonarSensor];

nxtDisplayTextLine(2,"SonarValue:%d",mValue);

12.Belowthetextthatwasjustwrittentothescreen,displayamessagethatsays“Searching For Target.”Becausenovariablewillbedisplayed,onlytwoparametersneedtobesenttothefunction,thelinenumberandthetext.

nxtDisplayCenteredTextLine(4,"Searching");

nxtDisplayCenteredTextLine(5,"ForTarget");

Line Follower Code:

13. Addtheline-followingcodethatwascreatedinLineFollowerExtensionPart3.

if(SensorValue[LightSensor]<50)

{

motor[motorD]=30;

motor[motorE]=0;

}

else

{

motor[motorE]=30;

motor[motorD]=0;

}

Launching an Object:

14. Addaconditionalstatementtocheckiftherobotiswithin25cmofthetarget.Iftherobotiswithin25cmofthetarget,display“Found! Activate Launch”ontherobotscreenandstopmotorD andmotorE.AddaWaitfunctiontopauseforonesecondtogivethemotorstimetostopbeforethenextactionisexecuted.

if(SensorValue[SonarSensor]<25)

{

nxtDisplayCenteredTextLine(4,“Found!”);

nxtDisplayCenteredTextLine(5,“ActivateLaunch”);

motor[motorE]=0;

motor[motorD]=0;

wait1Msec(1000);

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15.Spinboththetireson motorA andmotorB usingtheMotorfunction,andthenpausetheprogramforthreeseconds.Setthemotorpower,forbothmotors,tobeequalto100.

motor[motorA]=100;

motor[motorB]=100;

wait1Msec(3000);

16.AddaFor Loopthatmakesthearmservomovefromitscurrentpositionat128toalowerpositionof170,waiting10millisecondsbetweeneachmovement.

for(Position=128;Position<170;Position++)

{

servo[servo1]=Position;

wait10Msec(1);

}

wait1Msec(1000);

17.AddaFor Loopthatmakesthearmservomovefromitscurrentpositionat170toahigherpositionof128,waiting10millisecondsbetweeneachmovement.

for(Position=170;Position>128;Position--)

{

servo[servo1]=Position;

wait10Msec(1);

}

18.Next,stopboththemotorsthataremovingthetires,whicharemotorAandmotorB,usingtheMotorfunction.

motor[motorA]=0;

motor[motorB]=0;

19.Next,addaWhile Looptohavetherobotwaituntilthetargethasbeenmoved25cmormorefromtherobot.Thus,theconditionfortheWhileLoopstatementwouldbetocheckifthesonarsensorvalueislessthan25inordertosetbothmotorD and motorEtoavalueof0.

while(SensorValue[SonarSensor]<25)

{

motor[motorE]=0;

motor[motorD]=0;

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20.Next,displaythevalueofthelightsensorandthesonarsensorontheNXTscreen.Tosavetime,copyandpastethecodefromStep6.

nValue=SensorValue[LightSensor];

nxtDisplayTextLine(0,"LightValue:%d",nValue);

mValue=SensorValue[SonarSensor];

nxtDisplayTextLine(2,"SonarValue:%d",mValue);

21.Belowthetextthatwasjustwrittentothescreen,displayamessagethatsays“To Continue: Move Target.”Becausenovariablewillbedisplayed,onlytwoparametersneedtobesenttothefunction,thelinenumberandthetext.

nxtDisplayCenteredTextLine(4,"ToContinue:");

nxtDisplayCenteredTextLine(5,"MoveTarget");

End the program:

22.Typeaclosing bracetoendtheWhileLoopinStep19.

}

23.Typeaclosing bracetoendtheconditionalstatementinStep14.

}

24.Typeaclosing bracetoendtheinfiniteWhileLoopfromStep9.

}

25.Typeaclosing bracetoendtheprogram.

}

Completed Code:

taskmain()

{

intnValue;//lightsensorvalue

intmValue;//sonarsensorvalue

intPosition;//servoarmposition

wait1Msec(50);//Theprogramwaits50millisecondstoinitializethelightsensor.

servo[servo1]=128;//Initialservoposition

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Completed Code (continued):

//// Wait for touch sensor to be pressed to start.

while (SensorValue[Touch] == 0)

{

motor[motorE] = 0; // Motor B is off.

motor[motorD] = 0; // Motor C is off.

nValue = SensorValue[LightSensor];

nxtDisplayTextLine(0, "Light Value: %d", nValue); // update display

mValue = SensorValue[SonarSensor];

nxtDisplayTextLine(2, "Sonar Value: %d", mValue); // update display

nxtDisplayTextLine(4, "START:Press Touch");

}

while(true) // Infinite loop

{

motor[motorA] = 0; // left tire off

motor[motorB] = 0; // right tire off

nValue = SensorValue[LightSensor];

nxtDisplayTextLine(0, "Light Value: %d", nValue);

mValue = SensorValue[SonarSensor];

nxtDisplayTextLine(2, "Sonar Value: %d", mValue);

nxtDisplayCenteredTextLine(4, "Searching");

nxtDisplayCenteredTextLine(5, "For Target");

//// Line following Here;

if(SensorValue[LightSensor] < 50) // If the light sensor reads a value less than 50:

{

motor[motorD] = 30; // Motor D is run at a 30 power level.

motor[motorE] = 0; // Motor E is run at a 0 power level.

}

else // If the light sensor reads a value greater than or equal to 50:

{

motor[motorE] = 30; // Motor E is run at a 30 power level.

motor[motorD] = 0; // Motor D is run at a 0 power level.

}

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Completed Code (continued):

Launcher Programming Guide (ROBOTC®)

//// Sonar ranging here; Stop at target distance, start launcher and lower launch arm

if(SensorValue[SonarSensor] < 25) // Target sensed at 25cm, launch balls.

{

nxtDisplayCenteredTextLine(4, "Found!"); // update display

nxtDisplayCenteredTextLine(5, "Activate Launch"); // update display

motor[motorE] = 0; // Motor E is off

motor[motorD] = 0; // Motor D is off

wait1Msec(1000); // Pause for 1 second

motor[motorA] = 100; // Spin left tire

motor[motorB] = 100; // Spin right tire

wait1Msec(3000); // Pause for 3 seconds

for (Position = 128; Position < 170; Position++)

{

servo[servo1] = Position; // lower dispenser arm

wait10Msec(1);

}

wait1Msec(1000); // Pause for 1 second.

for (Position = 170; Position > 128; Position--)

{

servo[servo1] = Position; // raise dispenser arm

wait10Msec(1);

}

motor[motorA] = 0; // off left tire

motor[motorB] = 0; // off right tire

while(SensorValue[SonarSensor] < 25) // loop here waiting for target to be moved

{

motor[motorE] = 0; // Motor B is off

motor[motorD] = 0; // Motor C is off

nValue = SensorValue[LightSensor];

nxtDisplayTextLine(0, "Light Value: %d", nValue); // update display

mValue = SensorValue[SonarSensor];

nxtDisplayTextLine(2, "Sonar Value: %d", mValue); // update display

nxtDisplayCenteredTextLine(4, "To Continue:"); // update display

nxtDisplayCenteredTextLine(5, "Move Target"); // update display

}

}

}

}

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