Guest Blog #4: Excitement in Computer Programming

Our very own Matthew Bennett talks about the last two years with Raspberry Pi and his recent educational workshop on “Excitement in Computer Programming”.

Matthew (if you are forum denizen then you will know him better as ubermoderator ‘abishur’) has been involved in the Raspberry Pi community right from the beginning. He is a tireless moderator: prolifically helpful and unfailingly polite . We’re delighted that Matthew has stuck around and we’re proud to have him on the team.

The Raspberry Pi ethos shines in Matthew’s article: just roll up your sleeves and get involved. All of us can make a difference if we decide to.

N.B. Matthew tells me that there would have been more pictures but there was some excuse involving a baby…

A lot has changed around here since there were just a handful of us posting comments on a rather small blog and clamoring for a forum so we could properly talk to one another.  Back then, we thought that the 10 thousand boards they were making would take year(s?) to sell.  We definitely thought that everyone on the blog and soon thereafter on the very modest WordPress forum would definitely get one of the Pi’s from the first batch.  Needless to say the response to the Raspberry Pi has been tremendous, far outpacing even our largest expectations.

Unfortunately, one of the side effects of the demand has been the educational side of things hasn’t gotten as much of a spot light as all the incredible things you, the community, have done with the Pi; we asked what you would do with your slice of the Pi and man have y’all ever responded!  We are continuing to work hard on the educational aspects of the Pi and like updating you when fun educational things happen.

One such event happened in the middle of July.  Since the beginning of May I had been communicating with the Texas Industrial Vocational Association (TIVA).  They had me come out to their state-wide continuing education conference, which thankfully was in my neck of the woods, and talk on “Excitement in Computer Programming”.

Sorry about the picture’s quality, I shot it as I was on my way back home with a dying cell phone.

During the first half of the session, I worked with the teachers over why we even wanted programming taught in schools, why using iPads or other tablet devices didn’t work, and defined what we even mean when we talk about computer use vs computing vs programming.  The goal was to make sure that every educator attending could have a clear and concise case to bring to a principal or board of educators when it came.

The second half of the session was devoted to actual use of the Pi, we “installed” the OS, went through first boot, and then did the hello world of GPIOs: we lit up an LED!

Here is the outline and PowerPoint presentation I made.  I should warn everyone, however, that my outlines are tricky things.  They look like they’re written word for word what I plan to say, but they’re not, it’s still just an outline, it gives them a rough feel, but it’s there if you’d like a good base.  As way of example, here’s some things we talked about outside the outline:

  • The lack of a VGA port (no one felt it was a big deal)
  • Where the name Raspberry Pi came from.
  • Good programming languages to get kids hooked (I talked pro/cons of C/C++, Scratch, Java, and python)
  • GPIO expansion through SPI or I2C
  • Using it as a security system
  • Encouraging communities and especially the teachers themselves to offer contests for their students with fun prizes (Pi Merchandise, breadboard, etc)
  • iPads being used in some Texas school districts as teaching tools
  • Security (malware/network) concerns with Linux on educational networks

The parts I’ve bolded were reminders to advance the slide.  Also, I had planned to write the presentation and make the outline during my two week vacation after my son was born.  So if you pay attention there’s a spot where the amount of slides I was making suddenly decreases as I ran out of time (who knew babies were so needy?).

All in all, it was a lot of fun and we’re wanting to do this again at their midyear conference and again at their next summer conference along with some advanced classes.  One teacher is hoping we can set up a talk with his students during the school year.  Everyone who attended was pretty excited about getting Pis in their curriculums.

It’s not a real breadboard if it has never seen a fire.

Here’s a picture of my teaching setup. I use a Raspberry Pi Model A with Wi-Fi setup to connect to my phone as a mobile hot spot. My laptop also connects to the phone and then I can use my laptop to remote into the pi. If a projector is handy I just connect straight to the projector and use a combo keyboard/mouse instead of the wireless dongle.

I use the 8 solid state relays to demonstrate how the Pi can interface with high voltage applications, and the breadboard to demonstrate lighting up a simple multi-color LED using software emulated PWM to control how bright each LED is.

Oh, and there is a transistor array on that breadboard to demonstrate how easy it easy to add a layer of protections into the mix when interfacing with the 3v3 GPIO pins.



Marc avatar

Is that a burn spot on the breakout board?

Leestons avatar

Read the caption

“it’s not a real breadboard if it has never seen a fire.”

meltwater avatar

Always need to sacrifice some components to the Gods of hardware, it is just the way of things.

Abishur avatar

Yeah, good tip, just because a triac can handle AC voltage, doesn’t mean it can handle *any* AC voltage, even something as common as 120v AC. Poor little 24v AC triac.

Jim Manley avatar

Another example of how people today can’t do math – just because a zero digit has no value doesn’t mean 120 volts is the same as 12 volts! I’ve seen people actually make mistakes like that while learning electronics The Really Hard Way! As John Wayne said, “Life is tough, but it’s tougher when yer stupid!” :lol:

Doug avatar

“Security (malware/network) concerns with Linux on educational networks”

Could you provide some insight into how this discussion went? From my experience, schools are especially skittish about Linux (mostly due to fear of the unknown). Were they receptive? What concrete concerns did they have? Does seeing the Raspberry Pi as a special computing device (rather than a general purpose computer) help?

Abishur avatar

Fortunately they were all very receptive of the Pi including it’s Linux OS. The main thing we discussed was any malware problems that might come up from using Linux on a network. I explained that virus problems aren’t really a problem and not because of a lack of market share, but because Linux is a very secure system. You have to work to get Linux to a place where it can be easily compromised.

On the network side of things we discussed integrating Linux into existing domain structures. It’s really not that difficult to require authentication to an LDAP server when you log in.

Kevin Bowers avatar

A question and a comment, if you would:

Where did the SS relay bank come from? I have a project in mind that needs a bank of 8 relays. Hint: there are 8 notes in an octave, musically speaking.

As far as malware problems in Linux goes, in the world we live in today, it is simply not a problem; we Linux users are simply not a big enough target to make us worth worrying about. Some 95% of the world’s computers run Windows, another 4 1/2 OSX, Linux users share the rest with the rest of the fringe elements. Why in the world would anyone bother to write malware for one specific flavor of Linux on the off chance that it might find a host, when there are billions of Windows machines out there, many of which are still unprotected?

Jim Manley avatar

There are 12 notes in the even-tempered or well-tempered musical scales when you include the sharps and flats, and they’re needed when shifting music between keys. In the even-tempered scale, each note is the one plus the 12th root of 2 times higher in frequency than the adjacent lower note. In the well-tempered scale, the frequencies of certain notes are made to be proper fraction ratios of each other.

Those OS numbers are old and only represent desktops and laptops, as there are now hundreds of millions of iOS and Android mobile computing devices Out There that are in every respect computers, and then some when you account for touch, wireless networking, etc.

Android devices in particular are very attractive targets for hackers as they provide much more personal data in very canonical places in storage making it easy to snatch, and some sloppiness in the way apps can be loaded from who-knows-where also makes them more vulnerable than they should be.

Abishur avatar

The SS relay bank came from Sainsmart

Linux’s near immune status to virus’ really isn’t about a lack of market share. It’s because it’s a secure OS, they actually locked down files outside a user’s home directory and then they didn’t go storing a bunch of application data that can pass viruses to system folders within the user’s home direcetory. The huge leaks that hit Apple have proven that it’s not always about market share.

I admitidly do not bother to protect my windows comptuers, but I also don’t open e-mails from princes, go to adult orientied sites, or download files that will totally let me hax that w1nd0z3 program, and to be fair I gave up on the anti-virus programs because they just stopped protecting against the viruses that I do have to worry about that slip in an a single moment and take over the OS. For those viruses I use malwarebytes. That said, it’s been *years* since I’ve had any kind of virus on my windows pc

Michael Horne avatar

I wish I could bottle that talk you gave for the next Cambridge Jam!
The really weird thing? I’m currently sitting in Texas!

Abishur avatar

The amazing thing about Texas? It can take 18 hours to drive tip to tip (If you’re going north to south). We could both be in Texas and be further away than many people living in two neighboring countries. I’m up in the “North Central” part of Texas

Paulo Silva avatar

clive: “Please avoid using the term “PowerPoint” to mean any kind of slide presentation. “PowerPoint” is just the name of one particular proprietary program to make presentations, and there are plenty of free program for presentations, such as TeX’s beamer class and’s Impress.” ( )

liz avatar

Yeah, Clive. You suck. (There are no words to describe how enjoyable not having respond to comments while I’m on holiday is. Carry on as you were.)

clive avatar

Thanks Liz. I hope you choke on a pilchard! Oh! I’m sorry — I meant a small oily fish of the Clupeidae family.

liz avatar

They’re just sardines with attitude.

Chaz Molegrips avatar

liz: “Please avoid using the term “sardine” to mean any kind of canned fish. “Sardine” is just the name of one particular fish used in canning, and there are plenty of fish that can be used in canning, such as shads and pilchards” ( )

clive avatar

Hi Paulo.

I’m going out on a limb here and guess that you didn’t catch the first word of the title. I even did my bit in eye-talics and everything in case it was confusing. But cheers for the feedback!

P.S. Matthew’s presentation was actually a PowerPoint presentation. Which is why he called it a “PowerPoint presentation”. To call it anything else would have been affected, arbitrary, and well … kind of stupid and just plain wrong.

Abishur avatar

Hi yes, sorry I did write the article that Clive was so gracious to put up on the site and as Clive stated I did in fact use PowerPoint, it’s saved in a MS Office PowerPoint format, so I called it PowerPoint Presentation. I know that there are free (and mostly open source) alternatives out there, but I work for a company that let’s me take home a laptop and use it for work and personal use, it has MS Office on it so I use the tools it comes with ;-)

Abishur avatar

As a side note, I find it interesting that they don’t include “Xerox” on that list. My (step)Father-in-law works for Canon and get’s annoyed whenever I say I need something Xeroxed. He’ll always say “Xerox is a brand! You mean you need something copied!” Now he’s technically correct, but he looks mighty silly for making such a big deal over a word that has been integrated into common language to refer to a specific thing.

clive avatar

My real issue here is that you give up all this time freely and go to all this effort, and all some people can to do is to complain (wrongly) about the use of a single eponym. Me: I’m off to take an aspirin, do some hoovering, and play some frisbee :)

Keep up the good and important work Matthew! :D

Paulo Silva avatar

about “The lack of a VGA port (no one felt it was a big deal)” – i also agree that there should be a cheap, simple and easy HDMI to VGA adapter available?

clive avatar

We agree too! The problem is that to convert a digital signal (HDMI) to an analogue one (VGA) you need electronic trickery. Unfortunately this makes it not cheap, simple or easy.

Abishur avatar

Actually the conversation went something to the tune of

Teacher:”So does it have VGA?”
Me: “Nope”
Teacher “Okay, no biggie”

And then we discussed how the goal was to get this into kids hands where they could readily connect to a TV via HDMI or RCA or via a passive HDMI->DVI convertor to a monitor (which if you look in the PowerPoint Presentation, I suggest including an HDMI->DVI passive convertor in a preassembled kit for the student) that might be in the home.

Now if the goal of the pi was to fill existing computer labs in schools with Pis then yeah the lack of VGA would be a big deal, but since we’re aiming at kids connecting to available TVs then the lack of VGA becomes a moot point.

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