Wednesday, October 10, 2012

Nature and TurtleArt

Can you make a design like this in TurtleArt? In Logo?

Here is my first attempt.

Cynthia Soloman, one of the inventors of Logo, advised a group of Logo programmers at Constructing Modern Knowledge 2012 that the key to programming in Logo is to build small parts. Use the small parts to build larger parts. 

I built the flax plant with small pieces. Some pieces I built too big and went back and made them smaller. 

I made the white squiggles with a random numbers procedure, which is fun because it looks different every time you run the program.

Monday, October 8, 2012

Makey Makey Controller and My Adventure in Emulation

The Makey Makey lets you turn anything into an arrow key, space bar, or a click at its most simple configuration.

I built a simple keyboard with cardboard, paper, paperclips and hot glue. I used it to play the piano!

My latest project was to build a couple game controllers. Specifically, I was thinking of my ColecoVision and an old Coleco emulator, ColEm. Sure, I have a ColecoVision and an old TV to hook it up via an RF modulator, but I liked the challenge of building a controller reminiscent in shape of the classic ColecoVision controller.

ColEm is a Classic application, so I had to set up a working SheepShaver environment. I downloaded SheepShaver from MacUpdate. I found good directions for setting it up. I used an OS 8.6 disc for my System build on a 500 MB hard drive. I tracked down my backed up copy of ColEm that I used to run on my PowerMac 8600/200. I had a collection of ROMs that corresponded to my real collection.

Once I had SheepShaver running I designed a prototype hand controller to see if it would work. Cardboard is great prototype material because it is easy to shape and to put holes through. I started with aluminum foil buttons but they quickly wore out with the intensity of my play and left exposed sharp wires. I switched to metal screws and they worked well.

The cardboard did not have enough heft in the hand. It had good button layout and I liked being able to run the wires on the bottom of the controller.

The second iteration used a piece of furring strip and wood screws. It also has two fire buttons, one on each side. The wiring is on the front of the controller as well as the back and is held in place by the screw buttons and hot glue.

The third make is a bespoke controller with the buttons places where my thumb reaches the four directions. All the wiring is on the front of the controller.

Each model is unique. I think the second build would be good for younger people to use because they would naturally hold the controller with two hands and can control left/right and up/down with two hands.

I enjoyed playing BurgerTime, but I feel like I play that game better on the original ColecoVision. Q*Bert was also fun, and I learned that a friend's uncle designed that game!

Tuesday, October 2, 2012

TurtleArt: Procedures

TurtleArt comes with primitives, or programs that the turtle knows how to do. Here are the TurtleArt primitives for movement.

We learned that we can snap together bricks to make the turtle complete a series of movements. These connected bricks make a program. We can name this program, which teaches the computer a new command. Use the My Blocks tab and put a diamond-shaped block on top of your collection of blocks. Click on the block and you can type a name in the block.

Together, these collections of named commands are called procedures. Here are two procedures, one called circle, the other called donut.

The donut procedure uses the circle procedure. Since donut uses a forever block the turtle keeps drawing, which makes the shape seem animated.

Monday, October 1, 2012

TurtleArt: 3 Shapes

A fun TurtleArt challenge is to create three shapes:

  • Square
  • Circle
  • Triangle



Let us start with the square. As with many TurtleArt procedures, there is more than one way to create a square.
Some students put together a forward box and a left box and clicked it enough times to make a square. How many times did they have to click these boxes to make a square? 

Some students figured out that if they put enough forward and right (or left) blocks together they could make a square and only have to click once on the stack of blocks.

A really elegant way of making a square is to use the Repeat box. How many sides does a square have? This would be the minimum number of times you would have to repeat a forward and a right (or left) command to make a square.

A square has four sides, so you would repeat four times.


Next, onto the circle. Some students found the Arc block. The default settings are an angle of 180 and a radius of 100. Clicking it once gives us half a circle.

Clicking it twice gives us a whole circle.

What could you change to make it so you had to click only once on the Arc block to make a circle?

Here is another way to make a circle.

Why does the turtle repeat these commands 360 times?


The third shape was the most vexing for students. Some were able to make a triangle but only by picking up the turtle. It would be better to write a procedure that you could click to have the turtle draw a triangle without needing to reposition the turtle.

There are a few rules about triangles that are good to know.

  • If you have three equal sides, you will have three equal angles
  • If you have two equal sides, you will have two equal angles
  • If you have no equal sides, none of the angles will be equal
  • The sum of the three angles in a triangle equals 180 degrees
Muller, Jim. The Great Logo Adventure: Discovering Logo on and off the computer. 2nd printing. Madison, AL: Doone Publications, 1998. Print.

Knowing these rules makes drawing triangles easy.

Three equal sides:

Two equal sides:

No equal sides: