I’m working on a project that’s pretty scant on details at the moment, but it’s going to be based around a small computer with an attached LCD. I haven’t selected the display it will use yet, but the brains of the machine are looking like they will be an ARM based unit.
I’ve long held a high appreciation for ARM processors, having used them back in high school in Tassie. Back then there were a couple of labs of Acorn Archimedes machines – a computer ahead of it’s time. Acorn used an incredibly advanced processor for the time – the Acorn RISC Machine, or ARM. This was back in the heyday of the Amiga 500 and the i486, and the ARM was something quite different. Just about all other desktop computers were running Intel or Motorola CISC chips and the advanced RISC design of the ARM was perviously only seen in minicomputers. The power of the ARM processor was able to deliver a great desktop environment in RISC OS which had a number of features that really became popular many years later – such as pervasive drag and drop, context-sensitive menus, onscreen font anti-aliasing and an icon bar at the bottom of the screen.
Anyway, RISC OS is no longer with us in any meaningful way, but the ARM processor lives on and powers a huge number of devices that we use today.
Texas Instruments have made a great little development platform based around a modern ARM processor, the BeagleBoard, and I’ve got my hands on one. It’s got really good community support, a number of operating systems to run on it, and it’s available as both a dev platform and as more customised boards intended for use in end products, such as the Overo boards by Gumstix.
The BeagleBoard is pretty easy to work with – it’s got 256MB of flash and 256MB of RAM, so it’s not really that limited and can boot off SD Cards, so effectively has unlimited storage capacity for pretty much anything you’d want to use it for. It’s got a serial port onboard, so you can connect to the console that way – I’m using a no-name USB-RS232 adapter that fortunately has a relatively well-supported chipset in it. The whole board has a very low power usage, so can actually be powered via the USB port, or you can use a 5VDC adapter.
I’ve ordered a heap of other bits for the board from good ol’ DealExtreme and in typical DX fashion, items that said they were in stock are now still waiting for stock to come in 10 days after placing my order. As a result, I can’t hook up and old LCD monitor I’ve got with the DVI-HDMI cable I’ve ordered, and can’t use the USB for much as the hub and 5V power supply are also backordered.
I’ll post more as I work with the board. Today I was able to download an Angstrom image to a SD card and boot it to test the board, so it’s all progressing well. Next up I’ll build a Ubuntu Linux environment for it as I’m more familiar with that than Angstrom. Finally, I need to select a good, cheap LCD around the 6-10″ size and work out how I can drive that directly from the beagleboard without needing to go through the DVI port if possible…
why don’t you want to use the DVI port?
I want to use the DVI port for when I’m developing on the system, but for embedded use, if I can use I2C or something like that to talk directly to the LCD panel, it will simplify the electronics needed on the panel.
Depending on the LCD module used, there are output lines on the board that are taken off the bus before the framebuffer that are the right kinds of signals to drive the LCD, without needing the logic on the LCD to decode DVI signals and all that stuff…
If it turns out that it’s simpler to use a DVI interface on the LCD, then I’ll do so, but I’m under the impression at the moment that it can simplify things to talk to the raw LCD interface…
[quote]RISC OS is no longer with us in any meaningful way[/quote]
Have you been following recent developments? Try [url=”http://www.iconbar.com/articles/RISC_OS_on_new_hardware/index1233.html”]The Icon Bar[/url] for a start. Cheers 🙂
As much as I loved RISC OS, and will have some fun with it on the Beagle Board, by “meaningful way” I mean that you can’t walk into a store and buy a machine running RISC OS…
Depending on the LCD module used, there are output lines on the board that are taken off the bus before the framebuffer that are the right kinds of signals to drive the LCD, without needing the logic on the LCD to decode DVI signals and all that stuff…
If it turns out that it’s simpler to use a DVI interface on the LCD, then I’ll do so, but I’m under the impression at the moment that it can simplify things to talk to the raw LCD interface…
you are right
I’ll post more as I work with the board. Today I was able to download an Angstrom image to a SD card and boot it to test the board, so it’s all progressing well. Next up I’ll build a Ubuntu Linux environment for it as I’m more familiar with that than Angstrom. Finally, I need to select a good, cheap LCD around the 6-10″ size and work out how I can drive that directly from the beagleboard without needing to go through the DVI port if possible…