Archive for the ‘Teaching’ category

More Objective-C Hello World

September 28th, 2009

So, the joke in class was “will there be a HelloWorld27?”

Probably not, but we are up to HelloWorld4.

So the class is small, but made up of students with very different programming backgrounds. Two of the students are very comfortable in the Revolution environment, but are having some difficulty getting used to the C syntax. The other four students have used Java and/or Arduino, and while the syntax is different, they are finding it easier to adapt what they know to what we are doing.

I find for some students pictures are essential.

HelloWorld04

  1. Create a an image of yourself with the following dimensions:
    dimension
  2. Save it as a png on the desktop

  3. Open Xcode and create a new project

  4. Create a View Based application
    view_based

  5. Save it as HelloWorld04

  6. Open up the HelloWorld04ViewController.h file

  7. Create a UILabel pointer named label of type IBOutlet

  8. Below the closed curly brace create an (IBAction) named hello and pass it (id)sender

  9. Open the Implementation file and define the hello function so that the text of label is set to a message

  10. Save the files

  11. CTRL+click on the Resources folder and add the png. Make sure to Copy items into destination group’s folder(if needed)

  12. Open up the main nib file

  13. Double click on the HelloWorld04ViewController in the MainWindow.xib
    viewController
  14. Click on the link
    link
  15. From the library add a UIImageView

  16. In the attribute window set the image to your png

  17. From the library drag a UILabel onto the view. Adjust the size

  18. Clear the Text in the Text field

  19. Choose a color for the text in the attribute window

  20. From the library drag a button on to the view and change the label on the button to Press Me

  21. In the xib window click on File’s Owner and press ⌘+2.

  22. Connect label to the label in the view.

  23. connect hello: to the button and select Touch up inside

  24. Save the xib file

  25. Build and run

  26. Modify the code so that the text keeps toggling between two expressions.
    animation
  27. Add an NSLog() statement to print out the current text to the console.

  28. Save the xib file

  29. Build and run (⌘+⇧+R)

A Tone Generator and a Cool Purchase

September 24th, 2009

A few years back, I took a summer physical computing class at Parsons with Dan Mikesell. For our first circuit he gave us the following schematic and image to work with:
555circuit555pinout
I like this assignment because it introduces an IC chip, the NE555 Timer, and it makes an awful noise when it works. I also like it because initially it seems hard, but when students take a moment to think about the connections, it turns out to be quite simple. I always tell students to start with the GND and Vcc pins and go from there. It’s like solving a puzzle.

After displaying the schematic, I hand out a bag with the components. For each student, or group of students, I remove the components from the bag, name them, and describe their function. Then I leave students alone to figure out the wiring.

Today was Middle School Physical Computing and it was the last class of the day. Everyone was exhausted, but we still managed to play with the LED Resistor Calculator and two students out of eight were able to generate annoying tones.

Success!

I also purchased the Makerbot CupCake CNC for school today. Makerbot describes the “CupCake CNC as a rock solid open source 3D printer that is easy to build, easy to run, and easy to use. Its 100% open source, built to be hacked, and beginner friendly.” The plan is to have the High School students research digital fabrication and then build the printer in November. Very cool!

Piranha Leds and LED Resistance Calculators

September 22nd, 2009

It was the first Middle School Physical Computing class of the week today. Class was split between two activities. The first was lighting a 5mm Flux RGB LED piranha. While not told whether they had a common cathode or common anode LED, students were given the following information:
rgb_piranha
DC forward current 20mA
Red: 2V typ, 2.4V max
Green: 3V typ, 3.6V max
Blue: 3V typ, 3.6V max

After determining their resistor values, each student wired up their circuits to discover if their led was common cathode or common anode. Only one student managed to burn out the led by wiring both sides to power.

After creating some blended colors, students put the lights aside and went on to construct Evil Mad Scientists‘s LED Resistance Calculators.

Next class we’ll put the calculators to use and solve a few problems!

The Second Time Around

September 17th, 2009

In order to wire the circuits and cover all the topics, I put the following information on the board before class started:

  • VF= Forward Voltage/ Voltage Drop.
    The minimum amount of voltage needed to light an LED

  • lV= Luminous Intensity
    The amount of light emitted from an LED in a particular direction.
    The greater the numbers the brighter the light.

  • IF= Forward Current
    The amount of current the LED uses.

  • Viewing Angle
    The distribution or spread of light.

And the following diagram:
Ohm's Law

Again, all materials were either distributed or placed on the floor in the middle of the group. Students worked together and everyone wired the first circuit using alligator clips, the second circuit using the 12VDC power supply and the third and fourth which wired the LEDs in series and then in parallel. In order to demonstrate the different voltage drops, the class experimented with different colored LEDs.

Flashing LEDs were thrown into the mix because they’re cool.

Today’s class was the last of the day and when it was over, some students stayed late to chat and help clean up.

Hello World!

September 15th, 2009

clark

After spending the past summer gathering materials for my different classes, I thought it might be nice to share what I found inspiring, what I learned and how it all panned out.

Over the year, I will write about my experiences teaching Physical Computing, IPhone programming, and 2D and 3D animation to kids. I’ll try to explore what worked and what didn’t, what I would do again, and what I wouldn’t.

I’ve learned so much from various people, books and websites, and I hope that by sharing my thoughts, successes and failures, I can give back to a community that I have gotten so much from.

This is my first blog. wish me luck!