Raspberry Pi -A New DIY'ers Digital Hub?

wintermute

Administrator
Paid Member
2003-08-03 11:43 am
Sydney
I've written code a bit more recently than that, but I did start out on the C64 (6502 assembler.... blech) my hey day was with the amiga and 68000 assembler, these days it is the occasional c program, or more commonly shell script or perl. I'd seriously think about getting something like that for my daughter in a few years time!

Tony.
 
I've not read the article linked above but have been watching some of the raspberry pi progress.

One thing I'll be very interested to try out is RISC OS. From what I've read its booting and some minor problems still to be resolved but being actively worked on means there is a very cheap way of learning some different environments!

First batch of boards is supposed to be released to DIYers between now and xmas.

I had planned to get one and hook it up to a USB DAC when they get released. At those prices what have we got to lose!
 
This may be ideal for a car media player. I bought a "Mini 1080p" player off eBay, hoping it might be hackable. The hardware had a lot in common with the Raspberry Pi, but the chipset seemed to have no documentation available, let alone an SDK.

I'd better stop looking at those Linux discs and actually start working with it. Try to put together an audio player appliance using an alphanumeric LCD, USB audio, and basic controls (rotary encoder, a few pushbuttons.
 
The Rasberry Pi computer: $35 for the "loaded" version

This looks interesting, but is it limited to just very basic tasks or can it be programmed to do something a "full fledged" computer can do?

"Raspberry Pi $25 PC on course for January arrival"

Rasberry PI homepage - "An ARM GNU/Linux box for $25. Take a byte!"

It kind of reminds me of the Zenith/Heathkit trainer I used back in the 80s in college, which used, in our classes anyway, a 1mHz 8 bit Motorola processor (which IIRC was part of their 8xxx series), a tiny bit of RAM and a row of alphanumeric LEDs for info output and a number pad for info input - that was it. We had to use machine language which was really difficult at first, then when you realized how it worked, a light bulb would go on in your head and then it seemed a natural and really versatile programming language.
 

benb

Member
2010-04-24 1:52 am
I've done some Z80 assembly, and lots of 6502 machine (KIM-1) and assembly programming way back when. This isn't like that. Well you COULD do ARM assembly programming, but there are so many good compilers available thesedays for every processor that hand-writing assembly is becoming rare. I'm playing with MSP430's and smaller, microcontroller versions of ARM, and I do everything in C. I haven't done much assembly since the 90's when I used a Zilog (kind of off-brand) DSP with a really sucky C compiler.

This Pi thing is an 800MHZ ARM processor and 128MB or 256MB of RAM. It's got most of the power of a netbook. It practically IS a netbook computer, just add keyboard and mouse (through a USB hub, it's only got one USB connector onboard) and a video monitor. If you know anything about Unix/Linux and C programming, you already have an idea of what it can do. If you're thinking things like real-time digital filtering for crossovers, yeah this should do it assuming there's enough I/O bandwidth through USB. But there's a substantial learning curve in the programming.

There are already lots of Arduino/Atmel/PIC style microcontollers and cards around that run 20 to 50 times what the trainer did, with more RAM and easier-to-program FLASH memory to hold code, but these are still in the 20-50MHz clock rate range and 1k to 32K or so RAM and program memory.

If you want to do "basic tasks" with a microcontroller, get a TI Launchpad board for $4.30.
 
...handy module for developing cheap and easy to use digital playback systems.

I was thinking of a controller for biasing/switching in an amp i am envisioning...

Wonder how easy it would be to get a FORTH stack running on it? Been 40 years since i implemented one of those thou.

dave
 
Yup, this thing is a fully fledged pc that can currently run a few different linux distributions - I believe the development OS they are using most is Fedora.

There's no need to fiddle around with assembly language, or even C. Compiling a nice high level object oriented language like Java should be no problem. As dave mentioned, its basically an iPhone/android. I've written a couple of android apps - theyre written in java.

It also has a load of GPIO (general purpose I/O) pins. I don't know exactly what they are capable of as yet, but it could be that with the right software they are capable of almost anything.

I'm very interested in sitting this thing in a box with a Buffalo DAC, doing crossover and equalisation in software and feeding the DAC I2S.
BuffaloIII supports up to 8 channels over I2S, so maybe this is possible (I have a BuffaloII though, maybe it only supports 2?). I'm excited anyway
 
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Here's some good news for everyone:

RaspberryPiBoard - eLinux.org

The GPIO pins are able to output I2S. I'm going to get my hands on one of these when they're available for sure. I'm a software developer by trade... I hope I'll be able to get my head round making that happen!

This is an interesting board at this price point - the USB chip supports high speed (480Mbps) USB so for $25 and a small memory card you could boot linux with a dedicated small app running to convert from USB High Speed (with UAC2) to I2S without too much difficulty (for hirez or multichannel audio). The $35 device supports USB 2.0 but its not clear if the cheaper model with the embedded USB support in the SoC supports High Speed 2.0.

Could be a nice open source project!
 
I'm considering this as a web back-end for control.

my controller of choice, these days, is the arduino. its fast, talks very low level and is probably secure (no tasking o/s, no remote users, no nothing - just your code!). but the arduino is really too simple to be involved, directly, in the network.

the pi system, though, could have a full IP stack (in software, unlike the arduino ethernet shield which is ip-stack-on-a-chip) and it could have ip-tables or whatever firewall stuff you want. to me, that's the minimum needed to be a 'host' on a network. even a trusted network, I insist on some inbound security and access control. when you can change things via network, you need some decent access control. a linux software imple. can do this.

then, couple the linux engine to the arduino control engine over serial. not hard and its a nice abstract link. you can even debug and simulate each side on its own. and one does not need the other; you can have the core function of the box still run (arduino based) even if the optional networking feature is not installed. if you did the whole thing on the linux-pi board, you'd *have* to always have it. I'm not sure I like that architecture.

as soon as the pi's are buyable, I'll get one and see if its the linux engine I'm hoping it can be. ethernet on one side, lots of linux sw in the middle and some usb's and serial ports for comms: "mmm, that's good computin'!" ;)