//roverbot go back to its starting position after its proximity sensor is activated
//you may notice that it does not exactly go to its initial position if
//say its wheels slip or the ground is uneven
int returntime ;
int reflected_value;
void go_forward()
{
ClearTimer(0); //start timer(0)
OnFwd (OUT_A+OUT_C);
until (SENSOR_2 > reflected_value + 150);
returntime = Timer(0); //store value of Timer(0) when above condition is satisfied
}
void go_back()
{
OnFwd(OUT_A); OnRev(OUT_C); Wait (220); //to make a 180 degree turn. you might have to change the wait time
ClearTimer(0); //timer(0) started
OnFwd(OUT_A+OUT_C);
until ( Timer(0) > returntime );
Off (OUT_A+OUT_C); //switch off motor after coming back
}
task send_signal()
{
while (true)
{
SendMessage(0); Wait(20); //send IR signal every 0.20 sec
}
}
task check_signal()
{
while (true)
{
reflected_value = SENSOR_2;
if (SENSOR_2 > reflected_value + 150)
{
go_back();
}
}
}
task main()
{
SetSensorType(SENSOR_2, SENSOR_TYPE_LIGHT);
SetSensorMode(SENSOR_2, SENSOR_MODE_RAW); //light sensor attached to sensor 2
start send_signal;
start check_signal;
go_forward();
until (SENSOR_2 > reflected_value + 150);
go_back();
stop send_signal;
stop check_signal; //these 2 tasks must be stopped. if not, try putting your hands closer and
// closer to the light sensor, the roverbot will make a 180 degree turn.
}