Friday, October 23, 2009

SA BEST Game Day is Saturday, October 24

Today, SA BEST volunteers will tear down the game field and move it to the main auditorium in the Greehey Convocation Center. During the past week, the game field has been installed on one of the basketball courts in the Auxiliary Gym at Greehey. Our intent was that the field would be available for teams to practice with their robots. This afternoon, we will move the field and set up all of the support areas (pit, display, check-in, etc.). The last of the oral presentations will be given this afternoon and evening.

Tomorrow, Game Day, we will perform final checkout of the field and all support, and finish checking in teams at 10 AM. That's the signal for the chaos to begin. If you're coming, you might want to bring some earplugs, because it can get noisy in the gym.

Thursday, October 22, 2009

RFG final meeting

Yesterday, October 21, was the final meeting of this fall's Robotics for Grandparents class at ALIR.

I must apologize for my poor presentation of the material and the lab for Lesson 6. Although I was able to get the robots to communicate at home, they would not link up properly at ALIR, and so the lab was useless.

I did, however, have some video material on space program robotics, and was able to show several short video clips. The clips showed a variety of activities, including one with an astronaut riding on a workstand at the end of the Space Station RMS. Another clip showed the SRMS and SSRMS handing off and berthing the OBSS (alphabet soup!). SRMS is the Shuttle Remote Manipulator System; SSRMS is the Space Station RMS; OBSS is the Orbiter Boom Sensor System, an extension that carries cameras and other instruments for detailed tile inspection.

Toward the end of the class, our invited speaker, Mike Henry, arrived. Mike shared his enthusiasm for youth robotics, as well as a comprehensive coverage of the various programs for youth robotics in San Antonio. His brief talk was very well received, and I think he may have inspired a couple of new volunteers!

Just a reminder: On Saturday, starting about 10 AM, San Antonio BEST Robotics will hold its 2009 competition, entitled "High Octane". The game theme involves robots of the future operating a fuel refinery. The competition is held at St. Mary's University, in the Greehy Convocation Center. It's a free public event, so please come and cheer on your local team: home school, high school, or middle school. There are 29 teams competing this year, some from as far away as Laredo. I'll be there, and I hope you will, too.

Finally: It has been great fun teaching Robotics for Grandparents this year. I plan to return and teach it in Fall 2009. In the meantime, there are rumors that there could be a similar course for seniors taught as a continuing education course in the Spring. I hope that my students enjoyed Robotics for Grandparents as much as I did!

Tuesday, October 20, 2009

Tomorrow is the last class meeting for Robotics for Grandparents 2009

Due to time pressure from other activities (over-volunteering), I have had to reduce the scope of the lab for tomorrow's class.

My original intent was to write software for three robots that would establish one as the dance leader and the others as followers.  That's not going to happen - not right now, anyway.

The lab for this time will be to connect the three robots together with very simple programs.  One bot will wait for a button press, then send a message to the other two bots.  The other bots will wait for the message to arrive over Bluetooth, and will take some action (making a sound, moving, or other).

The NXT line dancers will have to wait for another day.

Monday, October 19, 2009

Demonstration Day at SA BEST

Sunday was the Demonstration Day for the teams in the SA BEST competition for 2009. Each team had to bring something that looked like a robot, even though incomplete, and an "Engineering Notebook" that described their concept and their work so far, as well as their methods. I'm going over the notebooks now, as one of the judges. They vary in quality, as would be expected. I have to have my review complete by noon today, so I can pass them back to the "Head Judge", Tom Deeter.

Friday, October 16, 2009

Encino Park Robo Club

At today's meeting of the Encino Park Robotics Club, I presented the kids with the same material I used for Wednesday's Robotics for Grandparents.
I had a small group - about a third of the club - and they picked up very quickly on the line-following technique and the details of the light sensor. I heard some interesting questions, and we answered many of the questions by trying experiments with the robot. We didn't get through all of the kids, so one of the teachers or another volunteer will use my Powerpoint slides and the line-following robot at next Friday's meeting. I invited the kids to come to the SA BEST competition on Saturday, October 24th.

Wednesday, October 14, 2009

RFG Week 6 (The Final Episode!)

Next week's lesson will cover Bluetooth communication among a set of NXT robots with almost identical programming.  One robot will command the others to move in sync (sorry, no music), and will do the same motions itself.

As a bonus, we will have a guest speaker, Mr. Mike Henry, who will discuss the several youth robotics programs that can be found in the San Antonio area.

Note to interested parties: San Antonio BEST Robotics is in the middle of a robotics competition.  The "Demo Day" will be held Sunday, October 18, in the Convocation Center at St. Mary's University on Culebra Road.  Game Day will be held in the same location on Saturday, October 24.  Details are available at the SA BEST web site, http://www.sabest.org/.

Week 5 of Robotics for Grandparents

Today the class tried calibrating a light sensor and following a black line on the test track. The results were good, and there was some interesting discussion about how line-following programs and devices work (and sometimes don't). A simple line-follower such as we were using can easily get lost and can't easily recover (its search for the edge is very simple).

On Friday, I'll show the line-following technique to the Encino Park Robotics Club. It should be fun to compare the 5th-graders' reaction to that of the grandparents!

Monday, October 12, 2009

Robots for RFG Week 5


The three class robots are built and tested, and ready to go to work! Instead of a third-wheel caster, the design uses inverted "claws" as skids on the front. The skids press the paper down (if on the paper test track) as the robot goes over it. The robot can go astray - losing track of where the line is - and sometimes it will recover and get back on the line. Other times it will loop around aimlessly.  In the class lab, we will use a version of the program that's split into two parts: a Calibrate program and a Follow program.

Wednesday, October 7, 2009

Week 5 Class

For Week 5 of Robotics for Grandparents, we will work with a new robot design that will follow a black line around the practice mat.  This will involve the use two programs: one to "train" the light sensor using calibration, and another to run the course following the line.  This design and program are from the web site nxtprograms.com.

RFG Class 4 - Ultrasonic Sensor and Display


Today's class covered a lot of ground in a short time. The lab problem involved the use of the Ultrasonic Sensor, the Rotation Sensor, the Touch Sensor, the LCD Display, "wires" to move data around, data conversion, and the "NXT Buttons" sensor. The objective was for the robot to wait until an object came within 12 inches (at the front), then move until touching the object, and display the distance moved (in degrees of wheel rotation). All three teams were able to complete the problem.

Sunday, October 4, 2009

RFG Week 4

In Wednesday's class, we will cover three sensors, the display, and signal wires

  • Sensors
    • Ultrasonic sensor
    • Touch Sensor
    • Rotation sensor (the servo motor as a sensor)
  • LCD Display
    • Displaying text
    • Displaying a number
  • Signal wires
  • Number to Text conversion

Saturday, October 3, 2009

EP Robo Club Meeting Friday


The Encino Park Elementary Robotics Club met again on Friday, October 2nd.  At this meeting, the teams were given challenges based on their readiness.  Those who were making the most progress were assigned a board challenge, in which they had to push an object to a point without going too far, then turn.  It was interesting to see how everyone attacked that problem.  Ms. Craig demonstrated how to use the motor's Rotation Sensor to find out how many rotations would go 12 inches.  I suggested that in this exercise the students use a pointer (like an axle) pointed toward the surface to precisely index the starting and ending locations. 

More on labeling

The Brother TZ tape doesn't stick as well as I thought. Next try is to wrap the TZ tape with some clear 3M tape.

MG Mathscript

I got a good, clear answer from the NXTasy.org forum on how to import a block to the NXT development environment. I now have the MG mathscript block in the Advanced group of the Complete palette. The key steps are:

1. You must have the block import/export wizard installed. It's a download available from the same place as new firmware versions.
2. Start the NXT application.
3. Open any program (it can be a new one like untitled-1) for editing.
4. From the menu, select Edit, then Block Import and Export Wizard. This will open a dialog that tells what to do next.
5. From the dialog, click Browse, and locate the folder with the block to be imported. You should now see the name of the desired block.
6. Select the desired block, and select a palette
7. Click the Import button, and you're done.

Thursday, October 1, 2009

Custom blocks from the Web

I found a very cool custom block called MathScript on the NXTasy.org web site.  It actually does high-level math by operating on text scripts. 



I've downloaded it to one laptop, and I think I put it in the right location, but the NXT development application can't find it.  There is a patch available to add the import/export block capability, but even after applying the patch, I can't get it to work.  A question to the NXTasy.org forum may bring me an answer.

Labeling stuff

I'm working with 3 or 4 Mindstorms NXT kits at a time, so the parts can get mixed around occasionally.

Because the NXT sensor/motor cables are all black, they're somewhat difficult to tell apart, and it's important at the end of the day for each kit to have the right assortment of cables: 2 of the 50cm cables, 4 of the 35cm cables, and 1 of the 20cm cable.

The way I can tell what goes where is to make two labels for each cable: one with the kit ID and another with the cable length on it.  So each cable is labeled "TPO1" and "50cm", for example.  Both labels are at the same end, for ease in sorting them. 


I used Brother TZ tape, 3/4 inches wide, red on white, with large lettering.  This tape wraps around the wire and sticks very well to itself.

A similar scheme will work to keep the USB cables from straying.  It might be useful to label the sensors and motors as well.

Wednesday, September 30, 2009

Appropriate age for Mindstorms

One student in RfG mentioned to me that she had a 4 1/2 year old grandson who might have fun with the Mindstorms kit.  I said I thought the kit was a little advanced for that age kid.  I suggested a couple of possibilities:

1. LEGO has a product line called WeDo Robotics, which is intended for younger children.  It's a little pricey, but many of the best LEGO products are pricey.  http://www.legoeducation.com/

2. As a parent-child activity, Mindstorms might be surprising, even though the child is young.  My grandson is 4 1/2 too, and he and his dad and I built a robot arm last week.  Ben has tiny fingers and is good at handling small parts, so he had an important part in the project.  Now he is expert at operating the 5-joint manipulator arm, and is proud to show it off.  The product is called the OWI Edge Robot Arm.  Ben also likes to work with me on Mindstorms constructions.

Class 3 Results

Today's class went well.  I tried out some new extra material, in which I discussed robots from my own professional perspective, which is space robotics.  I talked about the generations of robotic manipulators present in the Space Shuttle and Space Station programs, and I showed some pictures.  If I hadn't rambled on so long, I would have shown a few minutes of video, but timing wouldn't permit.

The class material and the lab were just about right in level of difficulty.  The class teams completed the exercise in about ten minutes each.  I noted that a MyBlock and a program need to have different names, and there's a possibility of tangling things up if they have the same name.

I have heard some interest in having a follow-on course (RfG II), and more questions about when the course would be taught again.  We'll have to see how this one goes before I try to design another course.  Susanne says that if I teach a second course, I'll need to get another robot kit to support it.  We'll have to see about that.  I'm not sure what material I would cover in a second course.

Tuesday, September 29, 2009

RFG Week 3

In tomorrow's Robotics for Grandparents class, I will introduce some new concepts:

  • Control structures
    • Loops
    • Branches
  • Subprograms
    • MyBlocks
If time permits, I will talk about the robots used on the Space Shuttle and Space Station.

All together now!

This afternoon I reinstalled the NXT 1.0 software on the two laptops.
I then renamed all 4 NXT bricks to TPO-1, TPO-1, EP-1, EP-2.
I downloaded new firmware 1.05 to all 4 NXT bricks.
I set the sound and light sensor calibration to default on all 4 NXT bricks.
I tested each brick to see if it worked properly with the sound sensor.

I think all is well now....

I would like to upgrade the laptops and the ALIR desktop to NXT 1.1, but I can't locate the installation CD.
LEGO no longer sells the NXT 1.1 CD.  Boo.  Maybe I can find someone to loan me the NXT 1.1 CD.

Monday, September 28, 2009

Great results from Mindstorms Tech Support

Today I called the Tech Support line for Lego Education.  I spoke to Tim Lankford, one of the tech geniuses they have there.  We talked through the problem, looked in a few places, tried a few things, and finally came to a good conclusion.  No hardware needs to be returned/repaired, no software bug report is needed.
The main point of misbehavior was that the Sound Sensor calibration on the problem NXT brick was messed up.  The minimum and maximum were reversed, and had weird values.  Setting the calibration to default values was the main part of the solution.

Here's what I need to do to get all the bots and computers homogenized:

  1. Uninstall the NXT software on all computers and re-install the latest (1.1) software.
  2. Download the latest (1.05) firmware to all bricks.
  3. Set calibration on the light and sound sensors to default on all bricks.
  4. Give each brick a unique name, similar to what's on the outside ID label.

Tim was intrigued by the idea of teaching Robotics for Grandparents!  Maybe he will follow our blog!

Thanks again to Tim for being very patient, knowledgeable, and helpful.

Sunday, September 27, 2009

TV News Story about robotic kidney surgery

Here's a news story about robotic surgery on a 7-year-old in Boston.  The furniture commercial is a no-cost extra....

http://wbztv.com/video/?id=24178@wbz.dayport.com

Movie "Surrogates" and an article

Susanne and I went to the movies today, to see the new science fiction film, "Surrogates".  Most of the humans in the film have been using robot surrogates to do all their daily activities, including going to work and other interactions.  There are a few contradictions in the film, but I won't nitpick it.  It was enjoyable, as a sci-fi thriller should be.

There is an article about the movie and the reality that you might want to read:

http://spectrum.ieee.org/robotics/humanoids/the-reality-of-robot-surrogates/0

Friday, September 25, 2009

Today's EP Robo Club Meeting

Today it was time to get finished building and get started programming the robots.  Some groups made more progress than others, but all of the time spent was well used.  One team had to start over with their building when they found that they were using building instructions from the old (1.1) kit and parts from the new (2.0) kit.  They were given an ambitious goal for the day, a programming task with several steps.  Next week they'll add some more capabilities and try some new tricks.  The teams are working well together.

Tutorials

I have found this tutorial series to be very useful.  It is mostly about using the NXT-G graphical programming system to control the robot.

http://www.ortop.org/NXT_Tutorial/index.html

NXT Brick problem

Lego Support has given me a case number for the NXT Brick problem.  I'll call them later today to see what can be done.

Wednesday, September 23, 2009

RFG Week 2

Today I wanted to demonstrate the combined use of a sensor and a motor.  So this morning, before the class, I connected a sound sensor to one of the robots and downloaded a little program.  The little program didn't work properly.  I put the sensor on a different port with no effect.  I replaced the sensor with no effect.  I replaced the sensor cable with no effect.  Then I replaced the NXT block, and it worked.  The visible effect of the problem was that the reading from the sensor was erratic.  Using VIEW, the sensor output seemed OK, but when I monitored the sensor output in the monitor window, it was erratic.  Hmm.  I replaced the batteries, hoping that would solve the problem.  No such luck.  So, during the class I let one team use the defective NXT block for the first part of the lab and then watch the other teams for the second part of the lab. 

Some good questions came from the lab - nobody was asleep for very long, I guess.  One student asked how to upload programs from the NXT block.  I knew it was possible, but didn't know how to do it.

Next week I will try to borrow another robot from the Encino Park Robo Club.


This is the robot configuration used for this week's class.  The sensor on the robot's left side is a sound sensor.

Monday, September 21, 2009

Spring Semester 2010

Some people have asked if I plan to offer the Robotics for Grandparents class next semester (Spring 2010).
The answer is no.  If there is interest, I will offer the class again in Fall 2010.

It's likely that the class will continue in the six-week format, which I think is about right for an introductory class.  I expect to revise the material based on what we can accomplish this semester.

Why not offer the class in the Spring?  Susanne and I have plans to travel during part of that time, and it wouldn't be fair to interrupt the class.

Saturday, September 19, 2009

Guest Speaker for Oct 21 class

For the last few minutes of the October 21 meeting of the Robotics for Grandparents class, we will have a guest speaker, Mr. Mike Henry. Mr. Henry has been involved for many years in youth robotics programs in the San Antonio area, and will talk to us briefly about the current state of youth robotics in San Antonio. He will describe the programs in our area, as well as the many opportunities for volunteers.

Friday, September 18, 2009

EP Robo Club meeting

I just returned from the Robotics Club meeting at Encino Park Elementary School. When I arrived, Mrs. Pearce told me that there was a mandatory all-teachers meeting, and asked if I could talk to the kids for a bit. As luck would have it, I had a flash drive in my pocket with a few minutes of Space Shuttle and Space Station animation that I'd downloaded earlier today. So we trooped into the computer lab, which has a projector and screen, and I showed them the animations and talked about what was going on. I think the kids enjoyed it, because they were quiet and attentive, and several of them asked probing questions.
When the teacher meeting was over, Mrs. Pearce and Miss Craig got the kids organized. Their task today was to organize into teams, name the team, assign duties, and build the starter robot using the Lego Mindstorms kit. Most of them finished and tested the robot by the end of the club period.

I brought one kit home and will use it in next Wednesday's RfG class. Here are some pictures from the work parties, including a finished and tested robot from Team 1.
This is the first meeting of the 2009-2010 club, and there were more volunteers, including four student volunteers from last year's robot club, serving as hands-off advisors. The club is off to a great start!

Robotics Club today

Every Friday at 2:30 PM, I join the Encino Park Elementary School's Robotics Club for a meeting. The club is made up of about 25 kids, mostly fifth-graders. Each year the school draws names from a larger list of kids who are interested in the club. During the club meeting, the kids do small projects assigned by the teachers. Sometimes they will prepare for a competition with other clubs within the North East Independent School District. Alice Pearce and Vicki Craig are the teachers who sponsor this club.

My job is to help the teachers run the club meetings, and to tell the kids about my own experiences with robots.

During the six weeks of the ALIR class, I bring the borrowed Lego NXT robot kit back to the school for the duration of the meeting.

Thursday, September 17, 2009

Next lesson (Week 2)

On Wednesday, September 23, the Robotics for Grandparents lesson will consist of two parts:

  1. Turning the robot, continued. More detail on ways to make controlled turns.
  2. Clap On, Clap Off. Discussion of sensors and how to make the computer correctly interpret data from the sensors (was that a handclap I heard?).

Web article about robots in healthcare

This article has some interesting words about robots in healthcare.

http://www.smartertechnology.com/c/a/Technology-For-Change/The-Robot-Will-See-You-Now-Intelligent-Machines-Boost-Health-Care/?kc=STNL09172009STR1

Wednesday, September 16, 2009

First class meeting is a success!






Today the Robotics for Grandparents class met for the first time. As expected, there were a lot of people, and the resources (PCs and robots) were stretched pretty thin.



Before class, I had a near panic when the "Baby laptop", an Aspire One with a 10.1 inch display, would not install the NXT software. The reason given was that the resolution of the display was insufficient. So my fallback was to use the Art Room computer for the third robot. When I installed the software on my new HP laptop, I got some odd results. Windows Vista (insert your favorite cusswords here) reported that the NXT software was not certified for Vista. I continued installation. When it came time to test the USB connection, all the USB ports were inactive. It turned out that was because Vista was attempting to update to Service Pack 2, which apparently disables some of the external interfaces. Anyhow, I stopped the SP2 update and rebooted the computer, at which time the USB ports came back. Panic over. When I arrived at ALIR, I realized that I didn't have the CD with class material on it. Not to worry, the older laptop had everything on it, so I copied the class material to a USB drive and took it to the Art Room computer. Waverly Jones of the Education Center staff had installed the NXT on the Art Room computer, as promised (thanks!).



As I said, there were lots of people who came to the class. I started by going through the Intro to Robotics presentation from Carnegie Mellon, which gave the class a good introduction to what we are going to do. Next, I gave a little demonstration of the NXT program editor and downloader.



Then it was time for the class assignment. The class problem required the robot to move straight ahead exactly 13.5 inches. The class members organized themselves into three groups (I expect those groups to be somewhat fluid). They worked together well, and came to (nearly) the same conclusion in about the same amount of time. Once a team had demonstrated their solution to the problem, I gave them an add-on: make the robot turn 180 degrees after stopping. The solutions for the turn varied somewhat, depending on how they did the turn.


By the time the teams had achieved the turn, it was time to wrap up the class.




I think the first class went very well. There was a lot of enthusiasm in the three teams, and the cooperation among team members was great.

Monday, September 14, 2009

Technical problem

The robot loaned by Encino Park Elementary's robotics club did something strange when I ran the little demo program to test it. It veered away from a straight line. It will take some more testing to determine whether the problem is in one of the servos or in a wheel or in the caster at the back. I will check the caster at the back first, by aligning it in a trailing position first, then in a leading position, then in a cross-path position. Each of those should produce a characteristic behavior. If that isn't the problem, I will check the tires. If one of them is mis-mounted on its wheel, I think that could cause the off-track behavior. If that isn't the problem, I will check the motors.

After checking again, I found no problems. Maybe a glitch, I don't know. Not to worry.

Saturday, September 12, 2009

SA BEST kickoff

Today, San Antonio BEST Robotics held its 2009 kickoff. BEST is a robotics program for teenagers, mostly high schoolers. SA BEST provides parts to build a robot that plays a game. The game for 2009 was kept secret until today, when 30 school teams attended. Now they have six weeks to build their robots. The prizes range from small trophies to BIG scholarships. There's more to winning than building the best-performing robot. Teams must demonstrate good engineering practice, sportsmanship, and knowledge of their robot. They must also prepare an engineering notebook that documents their process, ideas, and test results. Grandparents are encouraged to attend these tournaments to see what today's young people can achieve. Warning: It's very noisy on game day.

For information about San Antonio BEST, see http://www.sabest.org

Friday, September 11, 2009

ALIR Fall 2009 instructor meeting

Today ALIR held its Fall instructor meeting, in which the instructors for the semester are recognized, and new ones are introduced. We were given class rosters and some additional rules and regulations (e.g., no food or drink in the classrooms). Briefings on computer usage were given to instructors who needed them.



A member of the NEISD staff kindly offered to install my NXT software on the classroom computer I'll be using. That avoids any problems that the NEISD IT folks might have with me installing a *driver* (God forbid) on one of their computers.



I ordered 18 copies of my seven page handout (21 slides, I think). They should be ready in my mailbox on Wednesday morning.



I'm sending a note to the 18 registered and 6 waitlisted students, welcoming them to the class and inviting them to participate in this blog.

The Robots are Ready!


I have finished building and testing the three base robots for this class. They are built from the design in the Quick Start guide for the Lego 8527 Mindstorms NXT kit. Students will write, download, and run programs for these robots.
The school-club robot gave me some trouble last night. Its memory was missing the "Demo" program that I needed for testing. I did a hard reset (paper clip 4 seconds in the hole below the USB port). The result was, as expected, that the screen was blank and I could hear ticking from the speaker. When I tried to download new firmware, the NXT was not found. I checked the driver, which seemed to be OK. I re-installed the NXT package on my laptop, to no avail. Someone on the RobotC forum suggested I hold the pin in for 20 seconds. That didn't help. Finally, I removed one of the AA cells from the NXT and replaced it after 10 seconds. That was the ticket. The firmware downloaded, and everything was cool, except when I ran Demo, the motors were a little sluggish. Fresh batteries cured that problem. Since the batteries were fresh from last night, and were pretty warm, I conclude that when the NXT brick is in "tick tick" mode, it draws power and doesn't have enough intelligence to shut itself down. So, when in "tick tick" mode and frustrated, pull the batteries before quitting for the night.
This morning I have an ALIR instructor meeting, and I will take some handout pages for copying.
I'm told through the grapevine that there are even more people wanting to take this course. I'm not sure what to do about that, except to promise them that we'll be back next Fall.




Wednesday, September 9, 2009

What is Robotics for Grandparents?

"Robotics for Grandparents" is the name of a six-week course I'm teaching at the Academy of Learning In Retirement (ALIR). ALIR is a Continuing Education program of the North East Independent School District in San Antonio, Texas.

The purpose of the course is to let grandparents understand and enjoy what their grandkids are doing with Lego Mindstorms robots.

Class meetings are on Wednesday at 1:00 PM, and each class lasts 75 minutes. The first class is September 16, 2009.

The course participants will learn some elementary robotic skills, using the Lego Mindstorms NXT 1.1 kit. Our lesson plans will be taken from the Carnegie Mellon University web site.

Current enrollment in the class stands at 19 people. I had originally intended to limit the class to 8 people, because I had only one Mindstorms NXT kit for the students to use. When I found that the enrollment was up to 19, I had to reconsider some things. I purchased one additional Mindstorms kit, for later donation to a local elementary school, and I was able to secure the loan of a third kit from another school's Robotics Club. With three kits available, I can break the class into two groups of six and one group of seven.

ALIR is providing a classroom (the Art Room), which has plenty of table space for robot work, and which includes a computer, projector, and pull-down screen. Since the students will be programming and testing the robots during most of the class, I'll need to provide laptop computers. I have three laptops available, so there will be one laptop per group.

The first class meeting will be used for familiarization with the Mindstorms NXT robotic elements: sensors, computer, motors, and development software. The groups will be given a simple task for the robot to perform: move in a straight line for a specified distance.

I plan to update this blog at least once a week until the end of the course.

Questions and comments are most welcome.