//PROGRAM # 3

/* BUMP A LOT (revised)---- Tankbot with one touch sensor: it backs up and turns either left or right (random) when it runs into something. 2 tasks and 1 inline function. I use the inline function instead of subroutines because the subroutines are extremely limited. They cannot use any arguments! They cannot call another subroutine, and they cannot have a local variable if the subroutine is being called from multiple tasks. Subroutines do save space, as only a single copy of the subroutine code is used and shared by different callers. When using inline functions, another copy of the code is included in the program every time it is called, which takes up more of your limited space. The big advantage of inline functions is that it allows the use of 4 different argument types (see NQC Programmer’s Guide) which provide a great deal of versatility, even allowing a return value using the pass by reference argument "int &". */

// sensors- same as original Bump A Lot program

#define BUMP SENSOR_2

// motors- same as original Bump A Lot program

#define LEFT OUT_A

#define RIGHT OUT_C

// other constants

#define TURN_TIME 150 //1 1/2 second

#define REV_TIME 50 //1/2 second

#define NOTE 440 //frequency of sound

#define NOTE2 660 //frequency of sound

task main()

{

// configure sensor- tells the RCX that the sensor at port 2 (BUMP) is a

//touch sensor

SetSensor(BUMP, SENSOR_TOUCH);

// Robot moves foward

On(LEFT+RIGHT); //turns LEFT & RIGHT motor on

//begin task called “bump”

start bump;

}//main

//this task has the robot back up, turn (random right or left) and move forward

//if the touch sensor is pressed. It also plays a sound before turning

task bump()

{

while(true) //necessary or RCX will only perform task once

{

until(BUMP==1); //touch sensor pressed

int x = Random(2); //x is random variable (either 0 or 1)

if (x<1) //if x is 0, play “right” sound and turn right

{

playsoundR(); //Calls inline function “playsounR”

// back up

Rev(LEFT+RIGHT);

Wait(REV_TIME);

// spin around

Fwd(LEFT);

Wait(TURN_TIME);

// resume

Fwd(RIGHT);

}

else //if x is 1, play “left” sound and turn left

{

playsoundL(); //calls inline function “playsoundL”

// back up

Rev(LEFT+RIGHT);

Wait(REV_TIME);

// spin around

Fwd(RIGHT);

Wait(TURN_TIME);

// resume

Fwd(LEFT);

}//else

}//while

}//task

//inline function plays note at frequency 440 for 1/2 second

void playsoundR()

{

PlayTone(NOTE, 50);

}//return

//inline function plays note at frequency 660 for 1/2 second

void playsoundL()

{

PlayTone(NOTE2, 50);

}//return