source: rtos_arduino/trunk/arduino_lib/libraries/Robot_Control/examples/explore/R10_Rescue/R10_Rescue.ino@ 136

/* Robot Rescue

 In this example, the robot enters the line following mode and
 plays some music until it reaches its target. Once it finds the
 target, it pushes it out of the track. It then returns to the
 track and looks for a second target.

 You can make the robot push as many objects as you want to, just
 add more to calls to the rescue function or even move that code
 into the loop.

 Circuit:
 * Arduino Robot
 * some objects for the robot to push
 * a line-following circuit

 created 1 May 2013
 by X. Yang
 modified 12 May 2013
 by D. Cuartielles

 This example is in the public domain
 */

#include <ArduinoRobot.h> // include the robot library
#include <Wire.h>
#include <SPI.h>

void setup() {
  // initialize the Robot, SD card, display, and speaker
  Robot.begin();
  Robot.beginTFT();
  Robot.beginSD();
  Robot.beginSpeaker();

  // draw "lg0.bmp" and "lg1.bmp" on the screen
  Robot.displayLogos();

  // display the line following instructional image from the SD card
  Robot.drawBMP("lf.bmp", 0, 0);

  // play the chase music file
  Robot.playFile("chase.sqm");

  // add the instructions
  Robot.text("Rescue\n\n place the robot on\n the rescue track\n pushing the\n obstacles away", 5, 5);
  Robot.text("Press the middle\n button to start...", 5, 61);
  Robot.waitContinue();

  // start
  Robot.fill(255, 255, 255);
  Robot.stroke(255, 255, 255);
  Robot.rect(0, 0, 128, 80); // erase the previous text
  Robot.stroke(0, 0, 0);
  Robot.text("Start", 5, 5);

  // use this to calibrate the line following algorithm
  // uncomment one or the other to see the different behaviors of the robot
  // Robot.lineFollowConfig(14, 9, 50, 10);
  Robot.lineFollowConfig(11, 7, 60, 5);

  // run the rescue sequence
  rescueSequence();
  // find the track again
  goToNext();
  // run the rescue sequence a second time
  rescueSequence();
  
  // here you could go on ...
 
  
}

void loop() {
  //nothing here, the program only runs once.
}

// run the sequence
void rescueSequence() {
  //set the motor board into line-follow mode
  Robot.setMode(MODE_LINE_FOLLOW);

  while (!Robot.isActionDone()) { // wait until it is no longer following the line
  }
  delay(1000);

  // do the rescue operation
  doRescue();
  delay(1000);
}

void doRescue() {
  // Reached the endline, engage the target
  Robot.motorsWrite(200, 200);
  delay(250);
  Robot.motorsStop();
  delay(1000);

  // Turn the robot
  Robot.turn(90);
  Robot.motorsStop();
  delay(1000);

  // Move forward
  Robot.motorsWrite(200, 200);
  delay(500);
  Robot.motorsStop();
  delay(1000);

  // move backwards, leave the target
  Robot.motorsWrite(-200, -200);
  delay(500);
  Robot.motorsStop();
}

void goToNext() {
  // Turn the robot
  Robot.turn(-90);
  Robot.motorsStop();
  delay(1000);
}