Saturday, September 15, 2012

Day 1

SD Card

In the previous article, entitled Day 0, we talked about all the stuff you need before your Raspberry Pi can be up and running. We talked about the power supply as item #1.

Item #2 was the SD memory card (in blue on the picture):

This is the equivalent to a hard disk on a computer, for your raspberry pi. The official distribution (operating system), raspbian wheezy, requires a minimum of a 2GB SD card. These can be had for a few $. Less than $5 at any rate. But it is not worth the time. Start at least with 4GB. Considering that an 8GB card is to be found in brick and mortar stores for $8 and a 16GB for $14 (i'm writing this in september 2012), I'd even go with 8 or 16 if this is more than a toy.

If you go with a different distribution, such as the adafruit Occidentalis distro, then you have no choice but to go with 4GB as the minimum, and there it makes also a lot of sense to get an 8GB or 16GB card.

Having said that, there are also specialized distributions, one trick ponies so to speak, that can fit on 1GB and 2GB cards. It all depends what you want to do with your Pi.

Beside the capacity, you'll want to get the right speed, or "class". For example the blue sandisk 16GB on the picture above is a class 4 card. That is a minimum speed, imho. If you can get class 6 or 10, that is even better:

This one is a SanDisk 16GB also, but a class 10 that promises 30MB/s and that's a good thing.

Buyer Beware

Before rushing out and buying a card, I do want to mention a few things.

1. Not all cards are compatible. Check the LIST and make sure that it is supported. I've never had any problem with any SanDisk or AData cards with the Raspberry Pi, but apparently some people have had issues.

2. You will need a way to write the SD card. That means either an on board SD card slot (such as on the Mac mini and mac books) or a USB SD card reader like this:

This should work with Windows, Solaris / OpenIndiana, Linux and Mac OS/X. Typically, I've found that a lot of embedded SD slots, such as found on Sony Vaio (with the secondary slot for MagicGate) and Dell Precision laptops, tend to not create reliable images, under any OS. The USB on the other hand seems solid. In the end, the embedded SD slot on my Mac Mini seems rock solid as far as that, so I tend to stick to that.

3. The steps to copy the operating system software image to the SD card is a bit involved. If that scares you, there is another option:

Buy a card that already has the OS on it. This can be found on forums, through your local hackerspace, your local Linux user group, ebay, electronic distributors (in the case of Adafruit, they sell SD cards with their own distribution, Occidentalis, already installed) or online shops that specialize in the Raspberry Pi. You can also check the LIST for some other suggestions.

So, we are making some progress... Next time, we'll talk about the keyboard.

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