zondag 21 oktober 2012

Feeding your Pi

One of the first thing to do if you ordered that Pi without a pre-configured SD card is create one yourself. How hard could that be ..? Just download the 'Raspbian' operating system. and transfer it to a card. Now the download page tells you that 'Windows users should use Win32DiskImager' to transfer the OS to an SD card, but it looks like this software does not even see my SD card. Apparently I'm not the only one with this problem so I found that some people have successfully used the 'RoadKill DiskImage' software which indeed seems to work: That is to say it recognizes the card and writes to it.

Unfortunately: after placing the card in the Pi and power up, nothing happens. The OK LED does not blink and the laptop keeps telling me the Ethernet cable is unplugged so the Ethernet chip is probably not initialised.
Maybe Transcend 32GB is not the right type. So I tried the same procedure with a 4 GB Kingston microSD card. Same result.
Another search gets me to the eLinux wiki which again mentions the problem with Win32DiskImager but then suggests to use 'flashnul' software. Now this is Russian software, runs from the command line and contains some misspelled English texts but it seems to work fine. And indeed, after copying the OS to the 4GB card the Pi actually boots, the OK LED blinks and the Ethernet lights now all come up as well.

zondag 14 oktober 2012

Pi on Display

One of the goals of the Pi was to create a computer that you could use immediately without making much additional costs because you could use peripherals that were available anyway. Now the situation in the UK may be different but there's hardly a surplus of HDMI displays here. (Unused-) VGA displays however are everywhere but not supported by the Pi.
After reading that converting HDMI to VGA is rather complicated because it requires conversion from digital to analogue I started to fear the a suitable converter would probably cost much more than the Pi itself. And indeed most available converters look like this and cost between 40 and 200 dollars ! (2015 UPDATE: Though the link above is still valid, the price of the device has gone down to US$17,- ! Things still move fast in tech-space.)
So when I found this simple 'HDMI V1.4 Male to VGA Female Converter Adapter Cable' at DealExtreme I was a little sceptical. Would a $19,- cable, shipped for free from China, really do the same ? Since $19 is not too much money I decided to take a chance and placed my first order with this Chinese company. Ordering is very simple and within a few clicks the money is transferred from your creditcard to the other end of the world. And then the waiting starts. As mentioned on their website delivery can take upto 15 working days. Which just means three long weeks. And when its shipped through China Post there is just no way you can check the status of your shipment. Even though they have a site where you can enter the tracking number it never seemed to work for me. This is a very common complaint on many forums. The most valuable advice I found was to mark the expected delivery date on your calendar and not think about it until this date has passed. Which is true. Only just before the three weeks has passed the package arrives.
And most important: it works fine. I connected it to an old 1024 x 768 LCD monitor and the text and images appear crisp and clear.

Why should you want a Pi. ?

The Raspberry Pi is probably the most hyped single board computer ever. This $35 Linux computer is selling so fast that they just cannot produce them fast enough to meet the demand. In the week of their introduction the orders were up to 700 units per second ! And why ? What's so special about this little board that makes it so desirable ? Not much actually, and I think 90% of the sales is a kind of  mass hysteria that just pops up once in a while.
Lets look at the original goal: to get young people interested in computer programming in a way the Commodore 64 and ZX-81 did so many years ago. Which is a romantic dream of some men who grew up in this era and think they can transfer their youth to the present.
But the world has changed. Twenty years ago these home computers were the only way you could ever get close or even touch a programmable device. 

Starting a Linux based PC is not easy and requires some real skills. Indeed similar to loading and starting a program on a Commodore 64 or a TRS-80 from your tape-drive or double sided floppy. But there was a compelling reason for 10 year olds to learn these cryptic commands: it was the only way to load a COMPUTER GAME !. If you read the interviews with the all these successful programmers in ' Halcyon Days' you will notice that they all started programming because they wanted to create or play their favourite game. But with about every imaginable game available for free or for a few dollars in the app store this urge definitely no longer exists. I'm sure at least 80% of the Pi's sold so far  will just be used as a cheap mediabox.
Nevertheless, I could not resist to it either so I ordered one. And here I'll try to write down my experiences. Let's see if I can take it a little further than the blinking LED example...