Page 163 - The Unofficial Guide to Lego Mindstorms Robots

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start lightWatcher;
start touchWatcher;
start heartbeat;
}
task touchWatc her() {
while (true) {
if (SENSOR_2 == 1) {
SendM essage (FORWARD_MESSAGE);
Wait(10);
until (SENSOR_2 == 0);
SendMessage (STO P_MESSAGE);
}
if (SENSOR_3 == 1) {
SendMessage (SPIN_MESSAGE);
Wait(10);
until (SENSOR_3 == 0);
SendMessage (STOP_MES SAGE);
}
}
}

#define TOLERANC E 3
int curre nt;
int minimum;
int maximum;
int midline;

int lastArmMessage;

task light Watcher() {
minimum = 100;

maximum = 0;
while (true) {
current = SENSOR_1;
if (current < minimum) minimum = current;
if (current > maximum) maximum = current ;
midline = minimum + (maximum - minimum) / 2;

if (SENSOR_1 <= (midline - TOLERANCE) &&
lastArmMessage != RELEASE_MESSAGE) {
PlayTone(494, 10);
PlayTone(660, 10);
SendMessage (RELEASE_MESSAGE);
lastArmMessage = RELEASE_MESSAGE;
}
if (SENSOR_1 >= (middle + TOLERANCE) &&
lastArmMessage != GRAB_MESSAGE) {
PlayTone(660, 10);
PlayTone(494, 10);
SendMessage(GRAB_MESSAGE);
lastArmMessage = GRAB_MESSAGE;
}