Using the Scribbler 2

Goals

This lab introduces the Scribbler 2 robot and combines the Scribbler 2 with eSpeak.

scribblerlab.c: A first C program using the Scribbler 2 robot

Using the MyroC infrastructure to control a Scribbler 2 robot is illustrated in the program scribblerlab.c, which directs a Scribbler 2 robot to beep for 1 second. Steps for compiling and running the code follow the program listing.

/* This program illustrates how to connect
 * to the Scribbler robot, beep, and disconnect. 
 */

// include the library for Scribbler commands
#include  

int main()
{
  // connect to Scribbler
  rConnect("/dev/rfcomm0"); 

  // beep for 1 second at a frequency of 880 Hz.
  rBeep(1,880); 

  // disconnect from Scribbler
  rDisconnect();
  
  // return, indicating no errors have occurred
  return 0; 
} // main

Every program using MyroC to control a Scribbler 2 robot will need the rConnect and rDisconnect commands. The MyroC.h header file describes the full range of commands available for controlling these robots.

Compiling and Running Programs with MyroC

When using the gcc compiler directly, one must include information about where to find the relevant libraries for the Scribbler robots. The full command is:

gcc -Wall -Wno-deprecated-declarations -std=gnu99 -pthread -lMyroC -leSpeakPackage  -lMyroC -leSpeakPackage -framework OpenGL -framework GLUT   scribblerlab.c   -o scribblerlab

Although this line is long, the basic motivation involves identifying where the gcc compiler can find relevant pieces at various stages of compiling and running the program.

• -l indicates a specific library to be used when running a program. In this line, -lMyroC tells the computer to consult a MyroC file within a system library.

• -framework OpenGL -framework GLUT indicate two additional files of compiled code, both of which include details about handling images (e.g., from the robot's camera).

Since the gcc line is awkward (with numerous flags: "-l", "-W", and "-framework"), the suggested approach for compiling a program depends upon installing a Makefile, which supplies the relevant library information.

Also, if you have not done so already, copy this Makefile to the directory containing your program.

Assuming you have updated your .bashrc file, copied the Makefile, and called your program scribblerlab.c, you can compile the program using the following line in your terminal window:

    make scribblerlab

Once the program has been compiled (with compiled name scribblerlab):

• Be sure the Scribbler 2 robot is turned on, with its lights on.
  (If the program does not respond to subsequent commands, either turn it off and back on again, or press the "reset" button near the IPRE fluke card.)

• Run the program in your terminal window just as you would any C program:
      ./scribblerlab

eSpeak together with MyroC and a Scribbler 2 Robot

Programming a Scribbler 2 robot presents challenges in testing, because regular testing requires the programmer to look at both the robot and the code at the same time.

The eSpeak library provides a capability to resolve this problem, because the eSpeakPackage allows you to look at the robot while the program speaks the intended robot action.

The program, myroc-espeak-1.c, demonstrates the full capability of eSpeak with MyroC.

Although the details of the program require moderate length (about 107 lines), the idea can be described with just a few points:

• The program has 3 main parts:
  • Part 1 directs the program move in stages forward and to the right (3 times), with beeps of increasing pitch as it moves.
  • Part 2 directs the program move in stages forward and to the left (3 times), with beeps of decreasing pitch.
  • Part 3 is the same as Part 1.
• The program prints to the terminal at the start of each part.
• For each part, and during each Part, the speech synthesizer describes what the robot is doing.

/* Program combining test-to-speech capabilities
 * with Scribbler 2 motion and sound
 *
 * Part 1: robot moves forward and right three times 
 *         while playing an ascending musical chord 
 * Part 2: robot moves forward and left three times 
 *         while playing a descending musical chord
 * Part 3: repeats Part 1
 *
 * Author:  Henry M. Walker
 * Date created:  12 May 2016
 * 
 */

#include "eSpeakPackage.h"
#include "MyroC.h"
#include <stdio.h>

/* List musical notes for a C chord */
const int pitchC6 = 1047;
const int pitchE6 = 1319;
const int pitchG6 = 1568;
const int pitchC7 = 2092;

int main ()
{
  // connect for both MyroC and eSpeak
  rConnect ("/dev/rfcomm0");
  eSpeakConnect ();

  /* Part 1: robot moves forward and right three times 
             while playing an ascending musical chord 
  */
  printf ("starting Part 1\n");
  eSpeakTalk ("move forward and turn right");
  /* rForward, rTurnRight, rTurnLeft require
         speed and duration
     max speed forward is 1.0
     duration in seconds
  */
  rForward (1.0, 1.0);
  rBeep (0.5, pitchC6);
  rTurnRight (0.7, 0.75);
  
  eSpeakTalk ("move forward and turn right again");
  rForward (1.0, 1.0);
  rBeep (0.5, pitchE6);
  rTurnRight (0.7, 0.5);
  
  eSpeakTalk ("move and turn a third time");
  rForward (1.0, 1.0);
  rBeep (0.5, pitchG6);
  rTurnRight (0.7, 0.25);

  rBeep (0.5, pitchC7);

  /* Part 2: robot moves forward and left three times 
             while playing a descending musical chord 
  */
  eSpeakSetGender ("female");
       // specify voice characteristics
  printf ("starting Part 2\n");
  eSpeakTalk ("move forward and turn left");

  rForward (1.0, 1.0);
  rBeep (0.5, pitchC7);
  rTurnLeft (0.7, 0.25);
  
  eSpeakTalk ("move forward and turn left again");
  rForward (1.0, 1.0);
  rBeep (0.5, pitchG6);
  rTurnLeft (0.7, 0.5);
  
  eSpeakTalk ("move and turn a third time");
  rForward (1.0, 1.0);
  rBeep (0.5, pitchE6);
  rTurnLeft (0.7, 0.75);

  rBeep (0.5, pitchC6);

  /* Part 3: robot moves forward and right three times 
             while playing an ascending musical chord 
  */
  eSpeakSetGender ("male");
       // specify voice characteristics
  printf ("starting Part 3\n");
  eSpeakTalk ("Part 3 repeats Part 1");
  
  eSpeakTalk ("move forward and turn right");
  rForward (1.0, 1.0);
  rBeep (0.5, pitchC6);
  rTurnRight (0.7, 0.75);
  
  eSpeakTalk ("move forward and turn right again");
  rForward (1.0, 1.0);
  rBeep (0.5, pitchE6);
  rTurnRight (0.7, 0.5);
  
  eSpeakTalk ("move and turn a third time");
  rForward (1.0, 1.0);
  rBeep (0.5, pitchG6);
  rTurnRight (0.7, 0.25);

  rBeep (0.5, pitchC7);

  // finish with no errors
  eSpeakTalk ("Enough of this; I am going to stop now");
  rDisconnect ();
  eSpeakDisconnect ();

  return 0;
}

Although the idea of the program has structure (prologue and 3 parts), the long sequence of commands may obscure that structure. Later in this module, we will start exploring ways to clarify the structure and simplify elements of the code.