Category Archives: Physical Computing

BBC Micro:Bit arrives!

We received our BBC Micro:Bit today and are very keen to start playing around with it to find out what it can do. In addition to the Micro:Bit itself, the package contained a few other goodies such as: micro-bit_in_box_small

  • A Quick Start guide with tutorials to get you started
  • A USB connection cable to allow transfer of projects between computer and Micro:Bit
  • A battery pack and batteries to enable the Micro:Bit to become portable
  • A pack of crocodile clips to allow the Micro:Bit to connect to devices and sensors
  • A buzzer
  • An audio jack cable (haven’t worked out what this can be used for just yet)
  • A USB stick pre-loaded with examples projects

It’s worth mentioning that all of this has cost us precisely £0, so our thanks go out to the team behind the Micro:Bit for giving us the opportunity to test out this fantastic device with the aim of using it to deliver the Computing curriculum and hopefully inspiring the next generation of computer programmers.

We will report back when we’ve unpacked everything and taken the Micro:Bit for a trial run.

 

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A Visit to Bletchley Park

If like my stepsonBletchley Park and I, you find yourself in the wonderful town of Milton Keynes with half a day to spare, you could do a lot worse than take a trip to Bletchley Park, home of the WW2 codebreakers. It’s a pricey one (£16.75 for adults, £10 for children 12 to 16, under 12s free) but well worth it I’d say, especially if you have an interest in the development of Computer Science (or just an interest in WW2). For this is where Computer Science really came to the fore. It’s thought the code breaking carried out by the men and woman at Bletchley Park shortened WW2 by at least two years and saved millions of lives.

The recreation of Huts 3 and 6 (where most of the initial labour intensive code breaking took place) is very atmospheric, and in Hut 8 there are some interactive exhibits which attempt to explain how you go about trying to break cipher text (encrypted) messages. Unfortunately, we didn’t understand what we were doing on some of these exhibits. Cryptography can be quite a hard subject to grasp. It might be better if the exhibits focused on how to crack simple cipher text messages, rather than trying to explain how you go about decrypted messages as complex as those created by the German Enigma machine.

The famous mansion house is also very atmospheric, especially the sets from the recent film ‘The Imitation Game’, but the best bit about Bletchley Park is surely the museum (in Block B). Here you can see lots of Enigma machines, but also a working recreation of ‘The Bombe’: an electromechanical machine Alan Turing and Gordon Welchman built to speed up the process of decrypting Enigma’s cipher text messages. The Bombe made it possible to decrypt Enigma’s messages the same day they were intercepted. This was crucial, because the the encryption key (three dial settings) used by Enigma machines was changed at midnight every day. I must admit that again I couldn’t fully understand how the Bombe worked (despite watching a very interesting demonstration) but I did leave with a better understanding of cryptography and massive respect for the genius of Alan Turing. Without him, it’s quite possible I wouldn’t be here today writing this blog entry.

A Teacher’s Guide to Setting up a Raspberry Pi in School

I’ve setup a few Raspberry Pis in schools nRaspberry Pi 2ow, but each time I forgot what I did to get them working properly. So I’ve finally got round to writing some proper notes, and here they are. 

I’m going to assume you’ve managed to connect a monitor/tv, keyboard, mouse and ethernet cable to your Pi, and you’ve inserted a brand new NOOBS SD card. If so that’s great. Now switch on your monitor/TV, connect a 5v micro USB power supply to power up your Pi, and lets get started.

Initial setup

Choose Raspbian as your operating system (the top option).

It will take a while to install, then from the setup screen…

Choose option 3. Enable Boot to Desktop, then choose…

Desktop login as user pi

Then choose Finish and reboot.

Getting back to the setup screen at a later date

Useful if you need to change your locale, time zone, keyboard layout, or enable the Pi Camera.

Run the LXTerminal (the monitor/TV icon at the top) and type:

sudo raspi-config

Getting your screen resolution right (not always necessary – some screens look great first time)

Run the LXTerminal (the monitor/TV icon at the top) and type…

tvservice -d edid

then…

edidparser edid

This will tell you your monitor/TVs preferred mode. Something like this…

HDMI:EDID best score mode is now CEA (16) 1920x1080p @ 60 Hz with pixel clock 148 MHz (score 5398248)

Make a note of the bit that says CEA (16), or whatever it says, then type…

sudo nano /boot/config.txt

Uncomment the hdmi_group and hdmi_mode lines (this simply means delete the hash symbol # from the beginning of each line) and set the right values for hdmi_group and hdmi_mode.

  • “CEA” corresponds to hdmi_group=1 
  • “DMT” corresponds to hdmi_group=2
  • The value inside the brackets corresponds to hdmi_mode.

Press the Ctrl and O keys on your keyboard to save the file, then reboot your Pi.

Getting an internet connection (in school)

Connect your Pi to the school network with an ethernet cable (or install a wireless USB adapter – see notes below)

Run the LXTerminal (the monitor/TV icon at the top) and type…

ifconfig (to check you are getting an IP address)

Then set the proxy server by typing…

sudo nano /etc/apt/apt-conf.d/10proxy

Add one line…

Acquire:http::Proxy “proxyaddress:portnumber”;

Obviously replace ‘proxyaddress’ and ‘portnumber’ with the address of the proxy server your school computers connect to, and the port number. Ask your technician or local authority support team if your not sure what to put here. Or have a look in Internet Explorer on one of your school PCs. Proxy settings in Internet Explorer can be found beneath ‘Tools’ – ‘Internet Options’ – ‘Connections’ – ‘LAN Settings’.

Press the Ctrl and O keys on your keyboard to save the file, then reboot.

Wireless internet

Buy a Netgear N150 USB adapter (they just work! – might need to reboot after plugging it in).

Go to Preferences – Wifi Configuration from the raspberry menu (top left) to enter your school’s wireless password.

Updating Raspbian (do this occasionally to make sure it’s up to date)

Run the LXTerminal (the monitor/TV icon at the top) and type…

sudo apt-get update

Installing software

Run the LXTerminal (the monitor/TV icon at the top) and type…

sudo apt-get install [name of software package]

Obviously replace [name of software package] with the actual name of the package you want to install. You might need to do a bit of googling first, to find out the name of the package, although there is a nice list here.

Uninstalling Software

Run the LXTerminal (the monitor/TV icon at the top) and type…

sudo apt-get remove [name of software package]

Installing Scratch GPIO

You’ll need this version of Scratch if you want to work with sensors and the Raspberry Pi camera (and you don’t like Python very much). But, if your NOOBS SD card came with the latest version of the Raspbian operating system (Jessie), then you don’t need to do this, as you’ll already have Scratch GPIO installed.

Run the LXTerminal (the monitor/TV icon at the top) and type…

wget http://bit.ly/1wxrqdp -O isgh7.sh

then…

sudo bash isgh7.sh

Shortcuts will appear on your desktop.

Installing VNC

Great for accessing the Pi remotely; if you’ve set it up in the garden or somewhere! Use X11VNC, not TightVNC or RealVNC. It’s the only one that gives you a shared desktop.

Run the LXTerminal (the monitor/TV icon at the top) and type:

sudo apt-get install x11vnc

then…

x11vnc (to set a password)

then…

x11vnc (to start a session)

You should be able to access your Pi remotely, assuming you’ve installed some VNC client software on the computer you’re using to connect to it. Remember…

ifconfig (tells you the IP address assigned to your Pi).

Now you’re all setup and ready to go. Happy coding/inventing.