Tutorial 00a - Getting started on a Raspberry Pi
Latest revision as of 22:37, 4 January 2013
 Getting started (on actual ARM hardware!)
 Why would you want to use ARM hardware?
While you cannot beat the attraction of using an emulator (Tutorial 0 will get you running in five minutes!), something too good to be true has arrived.
That something is a complete ARM computer, with USB ports, ethernet, 256 or 512MiB RAM onboard, and a processor clocking around 700MHz. With an ARM11, it isn't cutting edge stuff (it predates the Cortex family)...however with a price tag targetted at $35, which translates to £30.87 (RS) or £33.16 (Farnell, uses UPS) [prices to the UK as on 2013/01/04; other countries will differ].
What I am saying is, yes, essentially you can get yourself an ARM-based system for experimenting and playing around for only thirty pounds!
- Note: There will be incidental costs; a keyboard and mouse, an SD card, a power supply, and some sort of display device. However if you already have computer equipment around, chances are that you'll already have most of this stuff that you can simply reuse.
If the cost alone isn't a selling point, let's consider some other benefits:
- Compatibility - firstly, the current emulators provide an emulation of a RiscPC, which is an aging (19 year old!) design with numerous restrictions.
- Autonomy - you aren't running a hosted environment in your normal computer, it is in itself a stand-alone device. The Pi is also remarkably low-powered (it will run quite happily from one of the USB ports on my eeePC!). Fancy having your own server? If your broadband router offers USB ports (such as a Livebox), you might be able to power it up directly from the router, plug in the ethernet cable, then just leave it running as your mini-server.
- Breakability - if you are experimenting and it all goes wrong and you fry the thing... well, would you rather fry a £30 device, or a £1000 laptop? Think about this a little harder if you fancy introducing young children to computers - for we both know it won't be an easy sell if you plan to introduce them to Scatch, Lua, or BASIC when they'll be more interested in "what happens if I poke it with this?".
- Autonomy 2 - a guy built a quadricopter that used GPS to fly itself. The heart? A RaspberryPi. That's just a whole pile of awesome right there.
- There's nothing like overspecified - do you have a home network? How about a Pi to open your bedroom curtains - by time of day, by light level, or by command across the network? I've thought of a design for a 6502 board to do this, and I've abandoned the idea for using a Pi is actually cheaper and it offers a lot more. Why stop there? When the camera module is released, one could be a door entry system working across the home network, another could monitor the temperature of your fridge and turn the refrigeration unit on and off accordingly (plus report the status and days worth of temperature recordings in a pretty PNG across the network...basically "because you can"); and so on, and so on. It is feasible even with a low paid job to buy a Pi every month or two, and once you know a little bit of code and get some hardware hacking under your belt, you could dream up some pretty impressive things!
This isn't to say that RISC OS is a one-size-fits-all (multimedia support is not so great at the moment, I hope for that to change in the future), however for some of the other projects, RISC OS does indeed offer the quickest and simplest way to get to the fun part - that's the part where you write code that does stuff!
 Installing RISC OS on a Raspberry Pi
Installing RISC OS on a Raspberry Pi is simplicity itself. The Pi boots from an SD card, so essentially all that is required is to put RISC OS on an SD card and put that into the Pi and power up.
Helpfully, this is remarkably simple as RISC OS Open have created a bootable image. It requires a 2 gigabyte SD card.
The process is as follows:
- Download the image and unzip it
- Download and unzip some sort of image writer. I am using Win32 Disk Imager as I am using WindowsXP.
- Write the image to the SD card. This is kinda slow, a generic SD card will write at around 6MiB/sec so it'll take around five minutes.
- Put the SD card into the Pi.
- Power up.
If you are using an HD monitor, that's it. There are some other things to be done if you are using composite video, especially if in a PAL country (the Pi defaults to NTSC).
It is all explained in this video. Please excuse the poor video quality, it was recorded "on the fly" using an old 8mm Sony HandyCam (and it shows!). I don't do fancy videos, I do videos that get the message across as simply as possible.
If you have difficulties understanding my accent, it may be useful to know that English language subtitles are available.
 Where to now?
Read the Crash Course in the original Getting Started tutorial if you have not used RISC OS before, or if you did "way back in school several eons ago". Some parts of RISC OS are very different to the Windows/Linux counterpart (two examples: no menu bar at the top of windows, and running an application will appear to not work because RISC OS does not open blank windows all over the place).