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Shooting Range made from Lego Mindstorm NXT

As we enjoy shooting out Nerf Blasters, I thought I would make a shooting range from Lego. The motors of Lego Mindstorm NXT have build in rotation detection, so they can be used and output an input. First the program at random picks one of the 3 motors and placed the target up. Then using the rotation detection it will detect a 'hit'. This happens with the slightest movement (1 degree or more). When the hit is detected the motor turn the target all the way down and a new random target is selected.

http://www.youtube.com/watch?v=E1wt5ywUo9M

The Lego code (designed in Bricx Command Center):

#define Power 75
#define DownTime 200
#define UpTime 200
#define TimePerTarget 2000

task main()
{

long rotate; /* the variable for recording angle */
long nothit;
int welke;
int m;
int score;
long time,time2;

TextOut(0,LCD_LINE2,"Angle on PortA");
score =0;
TextOut(0,LCD_LINE7,"Score:");
NumOut(40,LCD_LINE7,score);

while (true) {

OnFwd(OUT_ABC,Power);
Wait(DownTime);
Off(OUT_ABC);

Wait(2000);

welke = Random(3);
NumOut(0,LCD_LINE4,welke);

if (welke ==0) { m=OUT_A; }
if (welke ==1) { m=OUT_B; }
if (welke ==2) { m=OUT_C; }

OnRev(m,Power);
Wait(UpTime);
Off(m);

Wait(400);
nothit = MotorRotationCount (m);
rotate = nothit;
NumOut(0,LCD_LINE6,nothit);

time = CurrentTick();

while (nothit == rotate) {
rotate=MotorRotationCount (m); /* Read Motor angle [deg]*/
TextOut(0,LCD_LINE5," ");
NumOut(0,LCD_LINE5,rotate);
TextOut(40,LCD_LINE5,"deg");

//if ((time+TimePerTarget) < CurrentTick())
// { rotate = rotate + 10; }

}

OnFwd(m,Power);
Wait(DownTime);
Off(m);

score = score +1;

TextOut(0,LCD_LINE7,"Score:");
NumOut(40,LCD_LINE7,score);

}
}

1 comment

Jan 15, 2012. 12:58 AM

the_anykey (author) says:

The code is not completely finished yet. I already created a push button, so I can build a start/stop of the game. And I need to make the screen display nicer. But the listed code does already work for you to play with.