Page 197 - The Unofficial Guide to Lego Mindstorms Robots

186

while(true) {
if (BUMP_SENSOR == 1) {
// Say tag!
SendMessage(MESSAGE_TAG);
// Coast to a stop.
tagCommand = CO MMAND_FLOAT;
Wait(20);
// Check to see if we got an acknowledgement.
if (Message() == MESSAGE_ACKNOWLEDGE) {
PlaySound(3);
SetPower(OUT_B, sco re);
On(OUT_B);
if (scor e < 7) score = score + 1;
}
else PlaySound(2);
ClearMessage();
// B ack up.
tagCommand = CO MMAND_REVERSE;
Wait(50);
// Turn left or right for a ran dom duration.
if (Random( 1) == 0) tagCommand = COMMAND_LEFT;
else tagC ommand = COMMAND_RIGHT;
Wait(Random(200));
tagCommand = COMMAND_NONE;
}
else tagCommand = COMMAND_NONE;
}
}

int avoidCommand;
task avoid() {
while(tru e) {
if (LIGHT_SENSOR < averageLight - 3) {
// Back aw ay from the border.
avoidCommand = COMMAND_ FLOAT;
Wait(20);
avoidCommand = COMMAND_REVERSE;
Wait(50);
// Turn left or right for a random duration.
if (Random(1) == 0) avoidCommand = COMMAND_LEFT;
else avoidCommand = COMMAND_RIGHT;
Wait(Random(200));
avoidCommand = COMMAND_NONE;
}
}
}

int taggedCommand;

task tagged() {
while(true) {
if (Message() == MESSAGE_TAG) {
taggedCommand = COMMAND_STOP;