Shopping List - Painting Electric Circuits

This has gotten to be a bit of an obsession over the past few days. Using paint to create electric circuits.

Seriously, it is all I can think about. I am making a lot of  "this sweater is OK, but it would be awesomer with some LED light bulbs" statements that make my children hover between interest and a deep tween embarrassment that only mothers can induce.

It started with a CNN article on Pens that can be used to draw circuits. I know, great idea.

Except they are from the UK, and kind of pricey (12 pounds which is about $18 today). And according to my sources on twitter the conductivity isn't great once it is dried over long distances. That said the site has some nice classroom kits that include thumbtack batteries. There has been a hollow empty void in my life that is filled now that I know thumbtack batteries exist - you know what I mean?

Also according to the website these pens are available in Radio Shack, so good for those of us stateside.

Think Geek Conductive Paint

For about $30 you can get a 50ml tub of paint from Think Geek. I have visions of renumbering the computers in my lab using this ...possibilities are endless.

This appears to be the same company, so it is probably the same stuff that is in the pens, but it is a better price point for just the paint.

I also found a video describing how to make copper based conductive paint. Sounds fun, but given my overall free time...I might just head to Radio Shack.

MIT also has some resources listed:

• A Kit of No Parts has a great list, including sources

One of the main reasons I am interested is the application for wearable electronics. I am curious to see if the paint can be used to attach conductive thread to the power source. I'll let you all know if it works.

Need more inspiration? Here is a video of interactive wallpaper made with conductive paint. It plays music.

We do some very simple circuits and logic gates in the APCS Principles class suing play-doh. The play-doh works well because it can be changed and experimented with very easily, but the stuff dries out so nothing can be taken home. This paint would make a nice extension, especially if they can make something to take home. Prototype in play-doh then paint for permanent.

Coding Online - Updated

The original post has lots of updates - amazing how many web sites are available for coding.

List is here

As I get time this summer I will try to update as to what websites work on tablets/Chromebooks.

Play - Doh Logic Gates

Still working on Logic Gates in the Cs Principles class. Today they constructed logic gates using play-doh.

OR Gate

We started we watched this video connecting logic gates, AND and OR gates to binary numbers.

Before we did the logic gates I gave them a few challenge problems. I gave them a truth table and they had to construct a logic gate to produce the result. We used the logic.ly website to demo. Want to try one? Here you go:

Then they made logic gates with play-doh. The materials are fairly cheap. The most expensive part are the batteries and the battery holders (these run about $3). The good news is this activity works well with groups of 3 - 4 students, so you don't need a lot of these.

Materials:

• Play-Doh 
• LED lights
• Battery Holder (I use rechargable AA batteries)

I personally do not use the insulating play-doh. I am sure it would be helpful, but I barely have time to cook dinner for my own kids this week, much less make craft supplies.

I left the instructions very open ended. Each group got two battery packs, an LED and some play-doh. The instructions were to make an OR and an AND gate, and take a picture of each.

Post on PlayDoh circuit Ted Talk

Great Logic Gates Video

In CS Principles we have moved on from Data and are now covering Questions. In this unit we cover logic gates and if-thens. I want the students to make a connection between the hardware, all the binary we did earlier in the year, and how conditionals work in programming,

image from logic.ly online demo

Logic Gates Video

This explanation starts with a scenario - What if you need to trigger an alarm in a room with two sensors?

I love this approach. So often we start with the truth table, then go to a scenario, and by that point you have lost them.

After this we used the Logic.ly website to let them try making their own logic gates.

Next class we'll be watching this video explaining how the OR and AND gates are made. The students had a lot of questions about this today and this makes it pretty clear.

Coding Online -

Over the past year so many new tools for teaching Computer Science have arrived.

Image from Code in the Browser

Here are just a few:

• App Inventor - apps for Android devices
• Code in the Browser JavaScript
• CodeAcademy
• Javascript, HTML, CSS, API's, Python, Ruby
• CodingBat
• CodePad 
• C++, Lua, Python, Ruby and several others
• Code Spells * - kids learn Java by playing a game
• Computer Science Circles *  
• Python with explanation as you go
• Google Blockly *
• Khan Academy *
• Learn Street * - JavaScript, Ruby, Python, etc
• PHP for Kids *
• PythonMonk *
• Scratch 2.0 * (Beta)
• Snap Online
• Team Treehouse (not free)*
• Touch Develop *
• Try F# *
• W3Schools * - HTML, CSS

Also - a list of 10 free online resources, including MOOCs. *

Several of these let you start trying out code without really being aware of what language you are using. It leads to the question - does language matter?

I am starting to wonder if we even should be teaching a specific language in the beginning. Perhaps a better approach is to expose students to successful coding situations, build some positive experiences, then start to get more depth with one language.

This list is a quick start. Let me know if you know of any sites that should be listed.

*Updated 4/7/13

Obama Talks Computer Science

OK - this is an oldie but goodie. Then Senator Obama:

We are finishing the year in CS Principles by programming arrays and looking at data. Here Obama is being interviewed at Google. The question starts "What is the most efficient way to sort..."

It's Logical

So we are wrapping up conditionals in the CS Principles course. We have come so far this year, and I can see the light at the end of the tunnel. Part of me can't believe how much we have covered, and part of me wishes there was more time. I suppose something always gets cut.

Anyway, my goal this unit is to teach simple if thens, throw in some Boolean conditionals and relate all this to digital circuitry ala logic gates. Our final project for the unit will connect this to the Simulation part of the Abstraction Big Idea.

No small task.

For now I am stuck with C++, we have an existing curriculum I am doing the pilot in this class, so I have to get the students through arrays in C++. No wiggle room there. I am ambivalent about C++, it is a great language and I love working in it, but it is not the best vehicle for teaching good programming. It is fiddly to say the least.

On the other hand- BYOB Scratch is a great teaching tool. My original approach this year was to do Scratch first, then transition to C++. Wrong, wrong, wrong.

About two weeks back we were having a hard time getting though the classic leap year problem. I have taught this for years, and typically some kids get it right away, and some kids never fully get it. I had one of those "well, duh" moments, and we switched over to scratch. Within 10 minutes every student had a working leap year tester, could explain why it worked, and could explain how to choose good test data for this problem. We then went back to C++ and used the Scratch visual to build our C++ solution. Amazing!

So this will be my approach next year. Scratch as a prototyping language for C++ rather than two distinct topics. This will let us hit the coding about 6 weeks earlier next year, and if the last two weeks give any indication they should grasp the C++, and the underlying concepts, much faster.

Beep

So the Intro to Programming classes have been working on FOR loops this week.

We've counted up, down, by two. The only problem is at this stage they don't have much in their bag of tricks, so it is a lot of practice problems like "Print the numbers 18, 15, 12, ...3".

Today we were needed a bit more practice, but they are understandably underwhelmed by printing numbers. We use VB 6 for this class - so I took advantage of some of the sound options to help with the counting. We used the system beep to create sounds at different pitches. It means a whole day of laser zaps and bings. You can instantly hear the difference between counting by 5 or 500, and counting up and down get totally different effects.

Everyone was engaged and on task. Hard to sneak a nap with all the noise.

There is always one kid that decides to see how high it can go, which eventually gets painful. The best part of the day was when the fire alarm went off at the end of the day and it took us a second to figure out it was the alarm, not the kid with the extra fancy beeps.

Next week we'll start using the loops to process colors in pictures. We start with a self portrait project and end with a mini movie they develop and animate using VB. Lots of fun, and a lot less noisy.

Snappy CS Tools

Second day of VASS APCS training. Lots of fun stuff:

• Code Bat . Lets you code simple methods and it tests them for compleateness in real time.
• Light Bot Game that teaches methods and recursion.
• Jeroo
JeliotTraces Java code and snimated the steps
• App Inventor Make programs for Android
• BYOB Scratch