Monday, August 6, 2012

Raspberry Pi up and running

I received a Raspberry Pi computer about a month ago and had to put it aside to teach a summer course.  I also wanted some time to look around for a used monitor with an HDMI input since the RPi provides HDMI and composite outputs. It looks like HDMI monitors are fairly rare birds in North America so I settled for a Sabrent HDMI to VGA converter. At first I had trouble getting any output onto the VGA monitor but with a little bit of work I managed to get some fuzzy text going. The Linux Raspian "wheezy" OS gives you an initial setup screen. I did not pay close enough attention to it and so the keyboard is not configured correctly. I had to work through several discussion topics to learn how to edit the config.txt file to get a decent 1024 x 768 display. Now I'm learning how to add applications to the system - not an intuitive task and reconfigure the keyboard.
The RPi computer is a small single circuit board computer so you need to supply power, 5V 1A, to the micro USB power port. Mouse and a keyboard are no problem on the 2 USB ports. We all have SD cards laying around but the RPi requires a class 4 card. The SDRAM provides all the storage while the card/computer houses 256 Mb RAM.

Once you have all the pieces this computer works just as it should with an HDMI monitor. HDMI monitors are rare in Canada. I can purchase cheap used 4:3 LCD VGA monitors and even have a spare around the house. Since my budget was $100 I could not afford a new HDMI type monitor, they start at around $150. The adapter is my work around but, naturally, getting it to work was another problem. I think the lack of a VGA adapter is going to slow down interest in the RPi in North America. So after an initial setup using my daughter's TV (with HDMI input) I was able to get a very poor resolution output onto the VGA monitor using the HDMI to VGA adapter. From there some reading on line led me to a helpful post called setting up HDMI output. I altered the config.txt file several times until I found the best setting: hdmi_group=2 and hdmi_mode = 0x10. The config.txt file is best edited from the root terminal using nano /boot/config.txt (ctrl x, Y then enter - after making changes).

Some more reading led me to another useful post called Helpful Instructions for New Users where I learned the command dpkg-reconfigure keyboard-configuration to change back to a good old USA PC101 keyboard.

List of parts:

  1. $57.59  RPi board.
  2. $20.33  5V 1A USB power adapter.
  3. $60.14  Sabrent HDMI to VGA adapter.
  4. $03.93  HDMI cable.
  5. $14.68  Class 4 16GB SD card.
  6. $0          USB A to micro USB B cable.
  7. $0          Keyboard.
  8. $0          Mouse.
  9. $0          VGA Monitor.

Total $156.67
- includes tax, currency conversion and shipping charges.
- 0$ items found surplus on to learning Linux. If apt-get or Synaptic Package Manager don't get it and the installer is on the website then how do I install it? is an interesting interview with Raspberry Pi creator Eben Upton about the state of Computer Studies in the UK.