Wednesday, April 24, 2013

Raspberry Pi Computers in the classroom

On April 23 I hosted a student conference at Craig Kielburger Secondary School for students enrolled in the ICT SHSM program at my school and TA Blakelock HS in Oakville. In the morning the students enjoyed a Career Mash panel where 4 local business volunteers talked to the students about careers in the IT sector. Later the students heard about some of the excellent programs at Conestoga College including some degree programs like Integrated Telecommunications and Computer Technology Bachelors program. In the afternoon the students had 10 Raspberry Pi computers and had a First Look at this fascinating little computer.

Here is a quick 30 second video showing the students setting them up.

My August 6, 2012 post talks about my own Raspberry Pi set up. It still works well. The new kits comprise a Raspberry Pi, an Adafruit 1151 HDMI to VGA adapter, a 4 GB SDRAM card with the same version of Wheezy I used last August, mouse and keyboard, VGA monitor and 1A USB power supply. I had to modify the config.txt file and then clone 10 SD RAM cards for the students so that they would be able to boot up and get a graphics output to the VGA screen the first time. One of my students helped me out with this the week before the event and sure enough much head scratching ensued.

I started with my older version of Wheezy because I knew it worked with an HDMI to VGA adapter. I used a nearby Mac and an SD card adapter to quickly make changes to config.txt to try and find the correct settings for the Adafruit adapter. For the most part it looked to the other students as if we were staring at a black screen all afternoon! We were never able to get the latest version of Wheezy to display anything. That is why I stuck with my old version from last August. Adafruit's own forum was helpful in finally getting us going. These 2 commands will tell you which video modes the adapter supports:
/opt/vc/bin/tvservice -m CEA    // to get the CEA modes
/opt/vc/bin/tvservice -m DMT    // to get the DMT modes
It turns out that our brand new adapters only support CEA mode 1 (640 x 480 VGA), or just about the lowest resolution you can imagine. I'm waiting to see what Adafruit says about this.

Despite being limited to 640 by 480 the students quickly figured out how to make Scratch and Idle work to make Hello World programs. They got into the console and were able to use the command line for directory listing, running nano, ifconfig and ping and use the internet to find answers to their questions. There was much positive response and interest in learning more about this device. I'm going to repeat this exercise in a couple of days with some high school teachers.