Introduction to the course Computer Programming through Robotics CPST 410 Summer 2009

6/29/09Harry Howard, CPST 410, Tulane University2 Contact  Prof. Harry Howard  howard at tulane dot edu  (voice mail 24 hours a day)  Newcomb Hall 322-D  Office hours: right before class & by appointment (the link goes to my home page, which displays my Google calendar)by appointment  Course home page ( Course home page

6/29/09Harry Howard, CPST 410, Tulane University3 Show of hands  Who are the beginners?  Who are the continuing students?  You can do both.

6/29/09Harry Howard, CPST 410, Tulane University4 Goals - beginners  The goal of this course is to introduce you to the principles of computer programming by programming a small mobile robot.  We use the Lego Mindstorms NXT robot, v  This course will gravitate towards my interests in linguistics and cognitive science.

6/29/09Harry Howard, CPST 410, Tulane University5 Goals - beginners, cont.  However, it is an introduction and does not require any knowledge of computer programming, robotics, cognitive science, or linguistics.  It satisfies the formal discipline requirements for the Cognitive Studies (CGST) major.

6/29/09Harry Howard, CPST 410, Tulane University6 Objectives  For you to demonstrate your understanding of computer programming, you will perform the following tasks:  turn in a daily project,  turn in a final project by the final-exam day,  perhaps come to class.

6/29/09Harry Howard, CPST 410, Tulane University7 Objectives: weekly project  Turn in a project every day except the first & second  No project can be accepted late  10 * 7.5% = 75%  Even though these look like a lot of small grades  If you know ahead of time that you will miss a project, send me an and I will excuse you with no penalty.

6/29/09Harry Howard, CPST 410, Tulane University8 Objectives: final project  Turn in a final project by the final exam day (Aug 10). This may be a group effort, but the entire group will receive the same grade. [25%]

6/29/09Harry Howard, CPST 410, Tulane University9 Objectives: class participation  Note that there is no credit for class participation.  I will post my PowerPoint presentation to the class website after each class (my presentations are ugly so that you can print them easily).  I am recording myself and will post an mp3 (i.e. podcast) to the class website after each class.  So you don't have to come to class, if you can turn in the daily project somehow.  In any event, I will change any high X– into a Y+ if I notice you participating in class

6/29/09Harry Howard, CPST 410, Tulane University10 Code of Academic Integrity  “The integrity of Newcomb-Tulane College is based on the absolute honesty of the entire community in all academic endeavors. As part of the Tulane University community, students have certain responsibilities regarding work that forms the basis for the evaluation of their academic achievement. Students are expected to be familiar with these responsibilities at all times. No member of the university community should tolerate any form of academic dishonesty, because the scholarly community of the university depends on the willingness of both instructors and students to uphold the Code of Academic Conduct. When a violation of the Code of Academic Conduct is observed it is the duty of every member of the academic community who has evidence of the violation to take action. Students should take steps to uphold the code by reporting any suspected offense to the instructor or the associate dean of the college. Students should under no circumstances tolerate any form of academic dishonesty.”  For further information, point your browser at

6/29/09Harry Howard, CPST 410, Tulane University11 Students with disabilities  Students with disabilities who need academic accommodation should:  Contact and register with the Office of Disability Services (ODS). For more information, visit the ODS website at  Bring official notice to me from the ODS indicating that you need academic accommodation. This should be done before the first project.

6/29/09Harry Howard, CPST 410, Tulane University12 Readings  Textbooks  Beginners:  LEGO Mindstorms NXT-G Programming Guide by James Floyd Kelly (~$17)  LEGO Mindstorms NXT Power Programming: Robotics in C by John C. Hansen (~$22) Advanced  None, as of right now  Other readings: There may be supplementary readings, distributed as pdf files on Blackboard.

6/29/09Harry Howard, CPST 410, Tulane University13 Schedule of assignments  See handout or website for details of the schedule.website  Any changes to the schedule will be made to the website. website  I have never taught on this schedule before, so I do not know whether the syllabus is too fast or too slow. We will figure that out as we go.

6/29/09Harry Howard, CPST 410, Tulane University14 Odds and ends  We will cover pages a day, though Hansen's book is much denser than Kelly's

6/29/09Harry Howard, CPST 410, Tulane University15 Continuing students  Goals  To practice and expand on what you know  Objectives:  Turn in a final project by the final exam day (May 6). This may be a group effort, but the entire group will receive the same grade. [100%]

6/29/09Harry Howard, CPST 410, Tulane University16 Special for today  If you prefer to use an address other than your Tulane one, please me a message to that effect.

6/29/09Harry Howard, CPST 410, Tulane University17 Go over roster  And pass around sign-up sheet & camera.

Robots and programs Kelly §1

6/29/09Harry Howard, CPST 410, Tulane University19 What is a robot?  Kelly's definition  A robot is a device that is built to INDEPENDENTLY perform actions and interact with its surroundings. (p.1)  More generally, such things are divided into  autonomous robots  non-autonomous or remote-controlled robots  Autonomy is much more interesting and is what we are interested in

6/29/09Harry Howard, CPST 410, Tulane University20 What is a program?  Kelly's definition  A program is a set of instructions for a robot.  Programming is what you do when you create a program.  Robots, and computers in general, are DUMB!  Their instructions have to be extremely explicit

6/29/09Harry Howard, CPST 410, Tulane University21 The MINDSTORMS NXT application  The MINDSTORMS NXT application is the tool that you will use to create instructions for your robot  Version 1.1 is the most recent  The CDs that came with the boxes are v. 1  There are two flavors, the regular one (in the big cardboard boxes), and the educational one (in the plastic bins).  I want you to all install the educational flavor, which has the Robot Educator

6/29/09Harry Howard, CPST 410, Tulane University22 NXT-G  NXT-G is the programming language that the MINDSTORMS NXT application uses  Like I said the first day, it is a graphical language, which means that you build a program by inserting icons and moving them around  Most other languages are based on text, like the (not quite) C language we will use later on

Program structure Kelly §2

6/29/09Harry Howard, CPST 410, Tulane University24 Pseudo code  Before writing a program in the way that the robot understands, we will sketch what we want it to do in a way that people understand  Kelly calls this a 'fake program' but the technical term is pseudo-code.

6/29/09Harry Howard, CPST 410, Tulane University25 One example of pseudo-code  SPOT, move forward about 10 inches, turn left 90 degrees, and start moving forward, then start looking for a black object with your ultrasonic sensor, because I want you to stop when you find a black object, then turn right 90 degrees, and move backward 2 feet, OK? (Kelly, p. 8)  What is good or bad about this example

6/29/09Harry Howard, CPST 410, Tulane University26 A different phrasing of the pseudo-code example  SPOT, move forward about 10 inches and stop  Now turn left 90 degrees  Start moving forward, and turn on your ultrasonic sensor,  Stop when you find a black object  Turn right 90 degrees and stop.  Move backward 2 feet and stop. What is good or bad about this example?

6/29/09Harry Howard, CPST 410, Tulane University27 Pseudo and real code  The main advantage of the second phrasing is that we can match up the commands in each line to elements in the programming language  In NXT-G, these elements are called blocks.

6/29/09Harry Howard, CPST 410, Tulane University28 Test the robot!  Put in 6 batteries and see whether it starts up  Play with right and left buttons  To shut down  Go back to 'My files'  Press dark grey button  Press orange button for check mark

6/29/09Harry Howard, CPST 410, Tulane University29 Next time  Finish Tribot  NXT introduction  Movement, 'Going the Distance'  Kelly §1-4, 24  Bring your laptops!