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04 September 2012

So... What did I do with my Raspberry Pi?

Previous sections of this story:
Linux - Debian
After looking around for a while, and talking to one of my colleagues, who got their Raspberry Pi (hereafter, sometimes, referred to as "RPi") shortly before I did... I discovered that there was a "standard" install of Linux that had been packaged up, specifically for the RPi.

The community of RPi enthusiasts had got together, already, to package up a "disk image" just for users such as me (non-experts in either hardware, Linux or the relationship between the two) - thus making the whole thing a lot simpler.

Other things you will need

There are a few extra things you will need, to make your Raspberry Pi usable. They include:
  • a keyboard
  • a mouse
  • an SD card
  • something as a monitor
  • a power source

The "budget" effect

Having bought a computer for $38, you might find that other things suddenly start looking a lot more expensive. Suddenly, having to spend an extra $10 on your set-up feels like a very large % of the overall cost...

The SD Card

The SD Card you need is essentially the computer's "hard disk". It's where all the data the RPi will use to start-up is kept. There are fancy ways of starting-up with an SD card and then "switching over" to other sources - which I don't quite understand yet... but there's no escaping the need for an SD card to begin with.

Originally, I managed to source a 2Gb SD card for $7. I was told that I could find one for $4 in the Capitol Shopping Centre - but I must have walked into the wrong stores as I couldn't find any cheaper than the $7 I spent. It was a SanDisk - apparently a good brand, and fast - which can make some difference.

However, after loading the standard "Raspbian" image and then downloading a few packages, I found it wasn't large enough. After a couple of days I "bit the bullet" and bought another SD Card - an 8Gb SanDisk Card for $15.

I have ended up using the original 2Gb card as my daughter's Raspberry Pi set-up. As I will describe in more details later - the basic Raspbian set-up includes some quite interesting games, easily accessible from the GUI - which were really good for getting my daughter interested in this new toy I had brought home.

So - in my mind, I ignore the cost of the 2Gb Card, and see the total set-up and having cost $38 for the main hardware and $15 for the data storage.

The Keyboard and Mouse

The keyboard I used was a "roll-up" keyboard that we had lying around from years ago... by vague recollection it cost $10 at the time - but I like to think of it as a free addition to the infrastructure. Until now I have simply used a mouse from one of the other desktop computers in the house - another "free" addition.

The Monitor

So, now we come to the "monitor". It turns out that the Raspberry Pi has 2 monitor interface options:
  1. HDMI
  2. RCA
The VZ-200 - with RAM extension
HDMI covers most modern, flatscreen monitors - and RCA covers most old TVs and "composite" monitor options. But lots of cheap VGA monitors are therefore excluded. It reminded me slightly of my old VZ-200 (the first ever computer I owned), that plugged directly into a TV via an RF connection.

After thinking about it for a while, I realised, the only HDMI cable in the house was plugged into the back of our wall-mounted flatscreen TV - and was going to be difficult to remove. So, that made the TV pretty much my only option for a monitor, for now. I have a monitor, in my desktop set-up, that accepts HDMI, but I would need to buy a new HDMI cable in order to make it work - and the another $18, minimum, from china town.

And, as I've spoken about already, all these extra costs seem quite high, in the new world of the Raspberry Pi.

So - I settled for the TV, as a starting point. The TV in question was a present, from my brother-in-law... so I'm still counting that as a "zero-cost" to the project as a whole.

If you're happy logging into a machine via SSH, I'll describe, in a later post, how you don't really need a monitor once your RPi is up and running.

The Power Source

micro-usb plug
Finally, the RPi will run off any steady 5V source, using a standard micro-usb connection. Any standard USB cable will do. Most standard phone chargers will do. Myself, I plugged it into the USB port of the monitor of my desktop computer.

Apparently, there are ways to use AA battery packs to run it off - but there are some wrinkles regarding making sure the voltage doesn't drop below 5V. And, unfortunately, money seems to buy quality. Finding a low cost battery solution that supplies a steady 5V seems less than simple. I will update, here, should I find any further info.

Continue: "Installing an operating system on a Raspberry Pi" >>




2 comments:

Anonymous said...

Small correction. It's powered by a micro-usb cable, not mini-usb.

Nicholas Gledhill said...

You know... I woke up yesterday thinking "did I say 'mini-usb'?" But I hadn't had the time to check my work... I DO actually understand the difference which is more than you can say for some subjects :-)

Cheers. Correction posted soon.