Raspberry Pi first experiences

Raspberry Pi running Debian/LXDE and displaying the DesignSpark homepage

Excitement surrounding the Raspberry Pi has reached fever pitch as enthusiasts, engineers, and software developers and hardware hackers young and old, the world over, eagerly anticipate its arrival. I was one of the lucky few to get early access to hardware and this post details first experiences and initial thoughts on Raspberry Pi.

From unpacking to booting

The kit I received comprised a Raspberry Pi Model B (the version with Ethernet) and nothing else. But fortunately, or rather as one would expect, the additional hardware requirements are basic.

As a user of the Debian Linux operating system I was pleased to discover that a filesystem image of Debian 6.0 (Squeeze) had been made available, and I downloaded a ZIP archive containing this and followed the simple instructions to write it out to an SD card. This was then inserted into the SD socket, and the board connected to a USB keyboard and mouse, a LAN switch and power via USB.

Sadly, I didn't have the HDMI to DVI cable to hand that would be required to hook the Raspberry Pi up to my LCD monitor, but extremely keen to try the board out I dug around the workshop and found an old miniature CRT monitor that takes a composite video input. Also lacking a BNC to RCA cable, I attached a scope probe to the Pi's RCA socket output and the BNC plug to the monitor's video input. This worked as expected and I could just about read Linux boot messages as they scrolled up the tiny 2” CRT display.

I've since picked up HDMI to DVI and RCA to BNC cables, and can confirm that connecting the board to an LCD monitor also works as expected, but doing so does seem to turn off the composite video output. It appears to be possible to tune various parameters for the video ports via a GPU configuration file, but I've not found anything concerning enabling both outputs at the same time. It may be that users of the X Window System would simply achieve this by configuring via RandR.

Once booted I was able to log in as user pi with a password of suse, and from there to run commands as root via sudo. A UK-based mirror of the Debian software repositories had been preconfigured in the APT system, and by using commands such as apt-get it was possible to install familiar packages, e.g. OpenSSL, that had been built for the armel (little-endian ARM) port. Typing startx fired up X Windows and the LXDE desktop environment, and this can be seen in the image at the top of this post with a web browser displaying the DesignSpark homepage. The ssh server had also been enabled and it was possible to log in to the system over the network from my laptop.

Raspberry Pi board

Initial reaction

I was fortunate to have seen an alpha release board at the TransferSummit conference held in Oxford last September, I've seen pictures of the beta release and I was prepared for a minimal board. But it's not until you actually hold one of these things and compare the amount of I/O with the IC count (2!), that you come to truly appreciate the level of integration provided by a modern system-on-chip (SoC). It's an incredible achievement and almost certainly the only reason that it's possible to make a computer with these capabilities available at such a price point.

Just as I was impressed by the hardware, I was also impressed by the amount of supporting information available online. This ranges from authoritative documentation provided by the Raspberry Pi Foundation, to enthusiast blogs detailing experiences of working with Linux images on a PC using ARM emulation. Thanks to such documentation, the simplicity of the board and the availability of filesystem images, getting up and running with Raspberry Pi took no time at all.

My next steps

There are quite a few things I'd like to try out with a Raspberry Pi board and this includes adding 802.11 WLAN and Bluetooth support, driving hardware attached to the GPIO port, and building software from source. As I make progress I plan to post details to this blog.

Looking to the future

The amount of documentation created in advance of the Raspberry Pi's general availability serves as a clear indication of the latent energy in the community, whilst hinting at what might be possible with this level of intent and the availability of such highly affordable and flexible computer hardware. And it's exciting to see that a nascent marketplace for complementary technology is already developing, with companies such as Quick2Wire working on an experimenters kit.

Whilst the Raspberry Pi lends itself to all manner of uses, I feel that it is incumbent upon us as engineers to do all we can to help ensure that it is a resounding success in its intended application: enabling kids to experiment with computing. As Dr Jeremy Bennett pointed out in an interview on learning computer science and Raspberry

Raspberry Pi displaying an X Windows screensaver 

Note: whilst the tiny monitor shown above is not exactly practical, it serves as a fun demonstration and nicely illustrates how the Raspberry Pi can be used to bring use to old displays which take a composite video input.