View Full Version : Raspberry Pi
I'm really interested in this project - a basic PC for $35! ($25 if you don't want network and less RAM.)
I'm thinking particularly as an audio device - connected to an external usb HDD I reckon it could be a great basis for a Streamer system... Battery powered, maybe? It will be silent anyway, with no cooling needed.
I shall be trying to get hold of one when they start shipping in January, but I can see all sorts of possibilities for this, even if just used as a basic "surfer" connected to an HDMI equipped TV...
http://www.raspberrypi.org/faqs
http://www.theregister.co.uk/2011/11/28/raspberry_pi/
Very interesting and worthy project - good luck to them!
Yes, it's been on my radar for a while now, e.g:
http://www.pclinuxos.com/forum/index.php/topic,96488.0.html
http://www.geek.com/articles/chips/25-pc-alpha-board-successfully-runs-linux-20110824/
and should be of interest to hackers and modders.
The makers claim Debian support which is certainly known to run on ARM based embedded systems like the Linksys NSLU2, QNAP Turbo NAS etc. If it attracts enough interest a "raspberry PI" linux distro may even appear.
As a streamer, how it might compare to someting like an Alix board + Voyage MPD Linux needs some thought.
I wish the project success, if nothing more than it might give a much needed boost to computer science education in the UK which has been supplanted by dumbed down IT.
Mark Grant
23-12-2011, 09:45
Looks interesting and might spawn a new generation of 'tinkerers' that find out how things work rather than expecting everything to be windows 7 plug and play :)
The I/O board that the project is working on looks good for other uses such as low cost home automation projects, school education projects etc:
http://www.raspberrypi.org/archives/411
-
I've just watched this youtube vid:
http://www.youtube.com/watch?feature=player_embedded&v=6gX78qg6NQs
where the maker demos the alpha device at a NY Faire running a 1080 hd vid and talks about various techinical aspects of the project.
It appeared to boot a standard Debian ARM install from a SD card, but as explained has an exotic boot sequence due to the nature of the main broadcom 2853 chip used which is a combo of GPU, CPU etc. More details at:
http://elinux.org/RaspberryPiBoard
Defintely looks like a possible candidate for a networked device running MPD. If a Voyage MPD type install can be squeezed onto this, then it might have enough juice to to use audio flles stored on a USB stick (or streamed over a network via NAS or Web) with audio out over USB to an external DAC.
I realise now that they intend to sell SD cards with preinstalled versions of Linux as shown on their FAQ page : http://www.raspberrypi.org/faqs. With all the hard work done, it shoudn't be difficult to get this up and running with MPD using local or remote audio files and just ssh in to run the device headless, assuming it will boot without a keyboard or monitor attached.
I too am watching this closely.
I believe the XBMC dev team have XBMC running on a prototype Raspberry Pi - which would be great for me as I currently use an old PC to run XBMC streaming the files from my server and would love to replace this with a smaller, silent and more power-efficient device, but am not prepared to drop XBMC.
Keith,
A question was raised about XBMC here:
http://www.raspberrypi.org/archives/216
The answer was that XMBC were working on raspberry PI alpha boards, so your wish may be met.
Thanks for the link Chris.
Yet another vid, this time RaspPI running Fredora ARM + LXDE.
http://www.youtube.com/watch?feature=player_embedded&v=X9cmxoSmOxU
This give a better idea of X performance, it needs optimised x.org drivers. Not sure how it would cope with BBC iplayer HD flash. Better to download and run as mp4 I would think. Obviously, audio only should not be a problem and you could kill X.
I have a feeling the first batch of 10,000 will sell like hotcakes.
I have a feeling the first batch of 10,000 will sell like hotcakes.
I'm almost as excited as I was at Christmas 1983 when Santa brought me a 48K Sinclair Spectrum, in all its rubber-keyed glory! I haven't poked anything since! ;)
Reid Malenfant
23-12-2011, 17:44
I don't know much about this sort of thing, but it might be best to use WAV audio files rather than FLAC as the poor processor (which doesn't appear to be cooled by anything other than convection) will have far less work to do ;)
I'm probably wrong & it'd be 100% fine though, it's just the way my mind works :eyebrows:
I don't think that will be a problem, there are vids of the device playing a Quake demo at 1080p without overheating. Can a 700Mhz CPU decode/playback a FLAC file? No sweat, I think, if it's not doing much else.
Linux is flexible enough to boot your quad CPU powerhouse so it only uses one core by using the maxcpus kernel option. Then set the cpufreqd governor to userspace and set the CPU freq to say 800Mhz and it should give you a reasonable idea of what the CPU load and memory footprint its for audio playback with no X running.
I just tried to sign uo the the RaspPI mailing list but I'm getting errors. Is it just me?
Reid Malenfant
23-12-2011, 18:17
Good to know Chris, as I say I don't know a whole lot about this kind of thing :eyebrows:
About the mailing list, I can't say I have tried in all honesty ;)
PaulBarnett
24-12-2011, 11:13
Just tried a small experiment - my asus eee netbook runs at 900Mhz, but can be slowed-down in roughly 100Mhz steps down to 112MHz.
tried slowing it down while playiing a flac file thru amarok - no noticable sound change even at 112MHz (though the gui was very sluggish!!) - at this cpu speed, amarok was using about 25% of the cpu.
So, I think 700Mhz should be fine for flac, no need to go to wav.
Just tried a small experiment - my asus eee netbook runs at 900Mhz, but can be slowed-down in roughly 100Mhz steps down to 112MHz.
tried slowing it down while playiing a flac file thru amarok - no noticable sound change even at 112MHz (though the gui was very sluggish!!) - at this cpu speed, amarok was using about 25% of the cpu.
So, I think 700Mhz should be fine for flac, no need to go to wav.
Yes, that's about what I thought.
Some ball park figures after battening down the hatches on my quad core PC.
Running one core at 800Hz with no desktop and using MPD for audio playback, htop/top gives this data for CPU load and memory used:
Streamed audio via www - 5% Load / 131 MB
Local audio file (FLAC) – 3% Load /131MB
The memory usage should be reduced for a Linux install optimised for an Arm procssor. I can't give you full figures for my Voyage MPD Linux install as I haven't maintained it, nor does it allow the CPU to be ramped down. But for a local audio file (APE), it's 1.5% load/73MB.
Just to backtrack on what I had previously said about the Raspberry Pi and playing FLAC files, after reading the published specs fo the alpha board more closely, there is a DSP core but the API is not exposed to Linux and so there's no hardware acceleration for audio. Everything has been done on the ARM11 APU.
FLAC, AAC etc need floating point processing and it's not clear to me how well the ARM part of the Broadcom 2835 will handle this. This chips includes an ARM1176JZF which has ARMv6 architecture. Published data says it contains a floating pint coprocessor and suitable applications incude: “set-top boxes for digital audio and digital video, and three-dimensional user interfaces”.
I also found a reference to ARM releasing AAC, MP3, MPEG-4, H.264 and FFT OpenMAX DL Libraries, Highly Optimized for Cortex-A8/NEON and ARM11 Processors.
http://www.design-reuse.com/news/18429/aac-mp3-mpeg-4-h-264-fft-openmax-cortex-a8-neon-arm11-processors.html
This was in 2008, if/how these might have worked their way into Linux for ARM, I don't know.
Then there's the question of whether your favourite music server/client/player will work on a 700Mhz ARM APU. Well SqueezeBox-Server ha been made to work on sheeva plug computer which has a 1.2GHz Arm processor, see here for details:
http://wiki.slimdevices.com/index.php/Sheevaplug_SBS_Server_for_dummies
My preference is for MPD, and that has at least worked for audio playback on devices with ARM processores, but the problem, in both cases, may be if you need to simultaneously transcode/encode and stream from your audio server on such as device, e.g:
http://www.musicpd.org/forum/index.php?topic=2110.0
I did wade through some of the posts on the Raspberry PI forum which included various question about audio. Surprise, surprise, loads of people are thinking of using it for some kind of home brew media server. A few things struck me. Digital audio is included in the HDMI out which is at 1.3a spec, but there's no simple/cheap way to separate if from video. The analogue is supposed to be near CD quality, but is probably not acceptable to most. There may be a way to make a i2s link to the board for those thinking about connecting to a DAC. But for the electronically challenged, like me, USB out seems the obvious path to take. Simultaneous use of other USB peripherals may or may not degrade performance as might the use of a mobile phone charger as your PSU.
I haven't found a show stopper yet, so it still seems worth a punt, assuming you can get hold of one.
P.S. It's possible to emulate an ARM machine on your PC by using QEMU. Unlike, virtualbox or vmware, QEMU is software which can emulate processors other than just Intel and AMD.
I've never used QEMU, but there seems to be fairly detailed instructions for Debian and Fedora Linux on the web for anyone who's interested:
http://www.aurel32.net/info/debian_arm_qemu.php
http://fedoraproject.org/wiki/Architectures/ARM/HowToQemu
Excellent information and links Chris - thanks very much (and Paul for his experiment.)
I apologise in advance for this lengthy post which is tangential to the main thrust of this forum But as more of us become reliant on some form, or other, of computer audio, I thought other Linux users on this forum may be interested in the results of my efforts to emulate an ARM system running under QEMU in anticipation of the Raspberry PI..
As background, I should mention I have two working Linux installs in regular use. The first is a 64bit aptosid install with a full blown KDE desktop using ASLA as the sound base. The second is a lightweight 32bit aptosid install with XFCE and using OSS as the sound base. Aptosid Linux is itself based on debian unstable, which contrary to its name is stable.
The primary object was to make an audio connection over USB between my external DAC and the emulated ARM system and get some idea how a Raspberry PI might perform while running a MPD music server/client and doing other audio tasks. It would also confirm exactly what audio software was needed and if it resided in Debian's ARM port. Plus it would give indication of the level of difficulty involved in putting to together such an audio system
It was meant to be a quick test, so I wanted to avoid having to compile/build anything, something I'm not that proficient in doing, nor did I want to taint/bork my existing Linux installs. But in practice it turned out to be a more convoluted than I had hoped.
This was the rough sequence of events:
Installed QEMU on my existing aptosid (debian unstable) 64bit Linux install:
qemu --version
QEMU emulator version 0.15.1 (Debian 0.15.1+dfsg-3), Copyright (c) 2003-2008 Fabrice Bellard
Used these details as a guide to get an emulated ARM system running:
http://www.aurel32.net/info/debian_arm_qemu.php
but used more recent files from here:
http://people.debian.org/~aurel32/qemu/armel/
Got how to use USB with QEMU, and other, tips from here:
http://alien.slackbook.org/dokuwiki/doku.php?id=slackware:qemu
It actually emulated an arm5 CPU which was near enough for my purposes. But this is were I hit the first problem, the USB DAC was not being properly registered in the emulated ARM system and QEMU crashed with USB errors. I found no obvious fix to this bug accept possibly using the latest version of QEMU built from source.
But I didn't want to taint/bork my existing 64bit aptosid (debian unstable) install while compiling stuff. Luckily I found this ref which mentioned a QEMU version built by the Linaro software group and available as 3rd party Ubuntu binaries.
http://www.cnx-software.com/2011/10/18/raspberry-pi-emulator-in-ubuntu-with-qemu/
So I decided to use the Russian Dolls approach, and created an Ubuntu 11.10 VM in Virtualbox in order to run QEMU to emulate an ARM system. With the latest version of QEMU everything was looking good. I could connect my USB DAC to the Ubuntu VM and in turn connect it to the QEMU ARM system. You need root access to get USB working and a cumbersome CLI instruction, in my case:
qemu-system-arm -M versatilepb -kernel vmlinuz-2.6.32-5-versatile -initrd initrd.img-2.6.32-5-versatile -hda debian_squeeze_armel_standard.qcow2 -append "root=/dev/sda1" -usb -usbdevice host:08bb:2902
Next was the job of installing and configuring ALSA in the ARM system, and mplayer for good measure. So finally I got to test audio out over the USB DAC via the ARM emulation running inside the Ubuntu VM which was connected to my host system's audio output.
Oh bu**er, it doesn't work. :( Inside QEMU the “hw parameters” for the USB DAC cannot be set. This looked like a QEMU USB limitation.
Not one to give up just yet, I vaguely remember reading QEMU used OSS in preference to ALSA. But it was possible to override this by compiling QEMU from source with certain options and starting QEMU with additional options (export environment variables) so as to use ALSA. So I bit the bullet and again was lucky to find this guide:
http://raspi.springnote.com/pages/8235788
OK, all done. QEMU compiled with:
./configure --target-list="arm-softmmu" --enable-sdl --audio-drv-list=alsa
Environment variables set:
export QEMU_AUDIO_DRV=sdl
export SDL_AUDIODRIVER=alsa
qemu-system-arm --version
QEMU emulator version 1.0.50, Copyright (c) 2003-2008 Fabrice Bellard
But the same errors occurred in the ARM system. Hmm, I was getting nowhere.
My last effort was to consider using OSS in the ARM system and on my host. So this time I used my 32bit Linux install which is set up to use OSS. Compiled QEMU again, this time with the default OSS drivers. Run QEMU with the same lengthy command, and the ARM system fired up OK and the USB DAC was detected. Now I had to build OSS from source on the ARM system. There are debian ARM packages for OSS but they are not very current, and I know from experience that they don't work for USB audio.
There are clear instructions on how to build OSS from source here:
https://help.ubuntu.com/community/OpenSound
I found it best to get the OSS source via mercurial.
Unfortunately, OSS failed to build in the ARM emulation. As yet I haven't fathomed why. :scratch: This is the drawback of compiling stuff, debugging can be a time consuming process. Mind you being stupid doesn't help, my first effort threw out was weird messages which I stared at for 10 or more minutes before it finally dawned on me I had failed to check if any sort of compiler was installed on the ARM emulation.:doh: Even if I get OSS to build, and I'll probably need to ask for help on the OSS forum to do it, I'm not confident that same USB DAC hw parameters can be set from within QEMU. For good measure, I also ran this ARM emulation using ALSA and got the same USB errors as when it ran inside the Ubuntu VM.
If anyone else here succeeds with a similar exercise I'd like to know. In the meantime, the web, or some forum, might hold the answer as to if this can work in emulation.
Wow Chris - :respect: Hats off for your efforts - doesn't look like this is going to be an easy one, though!
Nice effort Chris - shame it didn't quite work.
I don't think I'm going to try and get an ARM emulation working, but will just get a Raspberry Pi when available - I'm sure I'll find some other use for it if I can't use it as a music streamer.
I'm sure raspberry Pi will offer working Linux builds on SD cards, and no doubt a how-to for DIY Linux builds will surface as they have for things like sheevaplugs etc.
I'm still confident the actual hardware is capable of being used for some sort of audio server.
It's doesn't help that the QEMU software is built to use OSS rather than ALSA, that's not a good mix. Actually, I've gone back to my working ARM emulation on which I had installed ALSA and realised there are some problems I missed. Before anyone ask, I did rememebr to add my user to the audio group.:lol: But alsamixer doesn't work and the oss-compat packages will not install correclty. That likely means the debian image I've tried to use doesn't have all the correct kernel config for al the ASLA stuff. I feel a kernel compile coming on, which means using a ARM cross-compiler. :eek:
I think I'll give that a miss for now, it's an age since I've compiled a kernel.
I'll focus on trying to get OSS to build on the ARM emulation and go from there. Just got to hit the opensound forum now for help.
Just to show I'm not a complete fantasist, here's some relevant output from the ARM emulation console.
The USB DAC is detected:
root@debian-armel:~# dmesg | grep usb
[ 10.760113] usbcore: registered new interface driver usbfs
[ 10.796943] usbcore: registered new interface driver hub
[ 10.804554] usbcore: registered new device driver usb
[ 11.861529] usb usb1: New USB device found, idVendor=1d6b, idProduct=0001
[ 11.882591] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[ 11.926665] usb usb1: Product: OHCI Host Controller
[ 11.949532] usb usb1: Manufacturer: Linux 2.6.32-5-versatile ohci_hcd
[ 11.970251] usb usb1: SerialNumber: 0000:00:0c.0
[ 12.030648] usb usb1: configuration #1 chosen from 1 choice
[ 12.736054] usb 1-1: new full speed USB device using ohci_hcd and address 2
[ 13.647982] usb 1-1: New USB device found, idVendor=08bb, idProduct=2902
[ 13.654038] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 13.659112] usb 1-1: Product: USB Audio CODEC
[ 13.664025] usb 1-1: Manufacturer: Burr-Brown from TI
[ 13.701832] usb 1-1: configuration #1 chosen from 1 choice
[ 15.006362] usbcore: registered new interface driver hiddev
[ 25.258277] generic-usb 0003:08BB:2902.0001: timeout initializing reports
[ 25.396718] input: Burr-Brown from TI USB Audio CODEC as /devices/pci0000:00/0000:00:0c.0/usb1/1-1/1-1:1.3/input/input2
[ 25.450808] generic-usb 0003:08BB:2902.0001: input,hidraw0: USB HID v1.00 Device [Burr-Brown from TI USB Audio CODEC ] on usb-0000:00:0c.0-1/input3
[ 25.539949] usbcore: registered new interface driver usbhid
[ 25.646441] usbhid: v2.6:USB HID core driver
[ 61.816870] usbcore: registered new interface driver snd-usb-audio
ALSA recongises it as sound device:
root@debian-armel:~# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 1: U0x8bb0x2902 [USB Device 0x8bb:0x2902], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
mplayer fails to stream an audiofile because of an USB I/O error:
root@debian-armel:~# !mplayer
mplayer -ao alsa:device=plughw=1.0 http://shoutcast.omroep.nl:8068
MPlayer 1.0rc3-4.4.4 (C) 2000-2009 MPlayer Team
mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.
Playing http://shoutcast.omroep.nl:8068.
Resolving shoutcast.omroep.nl for AF_INET6...
Couldn't resolve name for AF_INET6: shoutcast.omroep.nl
Resolving shoutcast.omroep.nl for AF_INET...
Connecting to server shoutcast.omroep.nl[145.58.33.95]: 8068...
Name : AVRO Baroque Around The Clock
Genre : classical
Website: http://klassiek.avro.nl
Public : no
Bitrate: 256kbit/s
Cache size set to 320 KBytes
Cache fill: 0.00% (0 bytes)
ICY Info: StreamTitle='Marc-Antoine Charpentier - Choeur de Chambre de Namur, La Fenice, Jean Tub�ry - Motet pour les tr�pass�s H.311 (Virgin Veritas 545394-2)';StreamUrl='http://klassiek.avro.nl';
Cache fill: 15.00% (49152 bytes)
Audio only file format detected.
================================================== ========================
Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
mpg123: Can't rewind stream by 69 bits!
AUDIO: 44100 Hz, 2 ch, s16le, 256.0 kbit/18.14% (ratio: 32000->176400)
Selected audio codec: [mp3] afm: mp3lib (mp3lib MPEG layer-2, layer-3)
================================================== ========================
[AO_ALSA] alsa-lib: pcm_hw.c:326:(snd_pcm_hw_hw_params) SNDRV_PCM_IOCTL_HW_PARAMS failed (-5): Input/output error
[AO_ALSA] Unable to set hw-parameters: Input/output error
Failed to initialize audio driver 'alsa:device=plughw=1.0'
Could not open/initialize audio device -> no sound.
Audio: no sound
Video: no video
Exiting... (End of file)
Blimey, the old grey matter hasn't had to work this hard for a long time. I think I was too quick to blame QEMU's USB support for this problem. It could still be the reason, but there's also the tangle of two different Linux sound systems, ALSA and OSS, and there's defintely some missing kernel modules in the files I'm using, let alone any errors in my ALSA configuration.
root@debian-armel:~# alsamixer
cannot open mixer: No such file or directory
root@debian-armel:~#
Glad I didn't embarass myself on any opensound forum, as it's obvious why OSS4 didn't build on the ARM emulation. It needs cross compilation, if it's going to work at all, and I have my doubts about that.
StanleyB
29-12-2011, 09:55
This reminds me of an inspector Colombo episode where he used the know how of a wine connoisseur, who also happened to have been the murderer, to solve the crime.
I have no idea what you are on about:scratch:, but your input is most valuable and fascinating. Keep it up, and in due course you'll be able to bring the rest of us on stream. Just let us know what tools we need at hand in order to replicate any experiments you can come up with.
I'll get one of those Raspberries as soon as they are available, just in case I can come up with some uses for it with my own products.
I have no idea what you are on about:scratch:
That's you and me both Stan. Honestly, I fee like I've gone back to school and I'm bottom of the class. No dobut I've made some basic mistakes on route as I hacked my way through this exercise. Now it's time to take stock and do I bit of serious homework. Just hope the old brain is still capable.
I'll get one of those Raspberries as soon as they are available, just in case I can come up with some uses for it with my own products.
I'm sure you'll have some good uses for it. Late Jan looks like the earliest date they will be available.
The first ten pre-production boards are now on ebay. Some people seem to be getting quite serious about them:
http://www.ebay.co.uk/itm/180786734741?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649#ht_500wt_1413
http://www.ebay.co.uk/itm/180786751081?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649#ht_500wt_1415
wee tee cee
01-01-2012, 18:50
This reminds me of an inspector Colombo episode where he used the know how of a wine connoisseur, who also happened to have been the murderer, to solve the crime.
I have no idea what you are on about:scratch:, but your input is most valuable and fascinating. Keep it up, and in due course you'll be able to bring the rest of us on stream. Just let us know what tools we need at hand in order to replicate any experiments you can come up with.
I'll get one of those Raspberries as soon as they are available, just in case I can come up with some uses for it with my own products. Is that the one with Donald Pleasance...." Liquid filth!!!! ", wine cellar had been left open too long...ferrari left on cliff top/scuba accident....the computer stuff has me bamboozeled ,,,,
Arm part 2 ….
The raspberry PI blog is effusing about the Ebay auction of beta boards and people's generosity, while the cynic in me wonders if it's just speculation on what some think will become collector's items.
I know even less about the dick in the raincoat than I do about what I'm trying to do here .. but in the spirit of epiphany I've had another crack at getting audio playback on my DAC's USB connection from a QEMU ARM emulation.
Firstly, I decided running QEMU inside Virtualbox could be introducing too many software layers and I had also completely forgotten that Ubuntu (VM, or otherwise) uses “Pulse Audio” which can get in the way.
Secondly, I dredged my memory banks for what I have learnt about the finer points of ALSA configuration (including config files: /etc/asound.conf; asound.state and .asoundrc).
Thirdly, I recompiled QEMU to work on ARM , i386 and x86-64, as I wanted to know if I could get any kind of audio out of a QEMU emulation. This I tested using both a 32bit and 64bit standard PC LiveCD.
I used thses QEMU commands to boot from LiveCD iso files:
qemu-system-i386 -cdrom voyage-mpd-0.8.0.iso -usb -usbdevice host:08bb:2902 -boot d -m 512
qemu-system-x86_64 -cdrom aptosid-2011-02-imera-xfce-amd64-201107131632.iso -usb -usbdevice host:08bb:2902 -boot d
Audio playback over the USB connection just worked, no tinkering was required. So why the struggle with ARM?
Partly this seemed to be a case of certain sound modules loading after the “setting up ALSA” message appeared during the system boot. I fixed this with a change to /etc/modprobe.d/alsa-base.conf so that there were no errors from any of these commands: aslamixer. aslactl init, alsctl store or alsactl restore, and during boot the “setting up ALSA done ...” message appeared.
But despite everything appearing to be a correct, audio playback over the USB connection still failed with a “usb_set_interface” error. :scratch:
Next, to satisfy myself it was not some problem in the rebuilt files I was using, I followed this guide to install debian ARM inside a QEMU emulation. But used the most recent debian-installer files and a more up-to-date kernel.
http://richizo.wordpress.com/2010/11/15/installing-debian-arm-under-qemu/
QEMU command used:
qemu-system-arm -m 256 -M versatilepb -kernel vmlinuz-3.1.0-1-versatile -initrd initrd.img -hda debian.img -append "root=/dev/sda1" -usb -usbdevice host:08bb:2902
I installed and configured ALSA etc, but still got the same error message on audio playback.:steam:
Next attempt was to follow this guide to configure and cross-compile a kernel targeted for an arm1176 cpu.
http://www.cnx-software.com/2011/10/18/raspberry-pi-emulator-in-ubuntu-with-qemu/
The prebuilt files on that page are no good as they were built without the necessary USB support. The mechanism of Kernel compilation is not difficult, unless you are trying to debug errors. The tricky bit is knowing exactly which options to include/exclude when configuring the kernel compile, and which bits can be modules and which should be built in. After a bit of judicious guesswork, I settled on a kernel configuration that proved to work. :)
cat /proc/cpuinfo
Processor : ARMv6-compatible processor rev 7 (v6l)
BogoMIPS : 481.68
Features : swp half thumb fastmult edsp java
CPU implementer : 0x41
CPU architecture: 7
CPU variant : 0x0
CPU part : 0xb76
CPU revision : 7
Hardware : ARM-Versatile PB
Revision : 0000
Serial : 0000000000000000
dmesg | grep usb
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
usb usb1: New USB device found, idVendor=1d6b, idProduct=0001
usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb1: Product: OHCI Host Controller
usb usb1: Manufacturer: Linux 3.0.4 ohci_hcd
usb usb1: SerialNumber: 0000:00:0c.0
usbcore: registered new interface driver uas
usbcore: registered new interface driver usb-storage
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
usb 1-1: new full speed USB device number 2 using ohci_hcd
usb 1-1: New USB device found, idVendor=08bb, idProduct=2902
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
usb 1-1: Product: USB Audio CODEC
usb 1-1: Manufacturer: Burr-Brown from TI
generic-usb 0003:08BB:2902.0001: timeout initializing reports
input: Burr-Brown from TI USB Audio CODEC as /devices/pci0000:00/0000:00:0c.0/usb1/1-1/1-1:1.3/input/input2
generic-usb 0003:08BB:2902.0001: input,hidraw0: USB HID v1.00 Device [Burr-Brown from TI USB Audio CODEC ] on usb-0000:00:0c.0-1/input3
usbcore: registered new interface driver snd-usb-audio
I completed this build and after sorting out the account expiry, apt sources, and installed ntp to keep time and the packages for ASLA, and copying a test.wav file over ssh, I was finally able to test audio playback. But ended up with just the same usb error :doh:
All this has been done using Debian Linux, now I read that the raspberry PI project is likey to adopt Fedora as its official Linux version.
I've never used Fedora, but I suppose I could try building a same type of ARM emulation using Fedora, there's a guide here:
http://fedoraproject.org/wiki/Architectures/ARM/HowToQemu
But, to be honest, I'm not confident that the results will be any different. SO I don't know if I can be bothered.
SO I don't know if I can be bothered.
Can't say I'm surprised Chris, you deserve a medal for your patience thus far!
Arm part 3...
I must be a gluten for punishment. Today I have a built a QEMU ARM emulation based on Fedora.
At first sight The Fedora guide looked horrible, but after a bit of thought I picked out what was relevant and was able to take a few short cuts. I tinkered with my Kernel compile configuration, more in hope than expectation, and the QEMU set up job was done in 45mins. Started the emulation and just had to use the fedora “yum” program to install a few bits of additional software.
And the result was .. you guessed it, the same USB error.
Just for laughs, I put together an QEMU ARM emulation built on ARCH Linux ARM. With all this practice, that was a fairly quick process. Arch Linux uses a program called pacman for its software management. On the first boot of the emulation there was very little tinkering to do to get to a point where I could test audio playback via my external SB DAC. But I just got the same old USB error.
Having tried this using debian, ferdora and now Arch Linux, with both re-built and my own kernel, I can only say that this some kind of QEMU bug, or all the kernels were defective in some way. I'm inclined to think it's a problem with the emulation software.
It's been an interesting learning experience and makes you appreciated just how tricky software development must be. We take that effort completely for granted in our point and click world.
I've got a few feelers out on Linux forums, and the next thing is to post a message for the QEMU developers. Is it a QEMU bug or not?
The things I'll do just to get my USB DAC to sing …..
PS Alex. Brio-R + Spendor SP1 - I'm a jealous guy.
StanleyB
29-02-2012, 17:29
Anyone managed to get hold of one today? I wasn't up early enough it seems:(.
Nope - me neither. Farnell accepted my order (after several hours of trying) and I've just had an 'expected delivery' email quoting 16th April.
terrybooth
29-02-2012, 19:38
Early days I guess. After all the distribution deal has only just been announced. I'll be keeping an eye out the the Raspberry Pi music player.
It crashed Farnell's website this morning, apparently!
http://www.bbc.co.uk/news/technology-17190918
For the moment it might as well be vapourware, as there's no chance of getting hold of one of the little beasties.
AFAIK the Fedora remix image is still not available, and the debian raspberry pi SD image posted for download a few days ago does not appear to include any standard sound modules, nor snd device nodes, and no ALSA package. I guess it's really not much more than an early development build.
If anyone wants to poke around in the deban SD image in Linux, here's how if you didn't know.
fdisk -l debian6-17-02-2012.img
Disk debian6-17-02-2012.img: 1977 MB, 1977614336 bytes
4 heads, 32 sectors/track, 30176 cylinders, total 3862528 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0000cded
Device Boot Start End Blocks Id System
debian6-17-02-2012.img1 2048 155647 76800 c W95 FAT32 (LBA)
debian6-17-02-2012.img2 157696 3414015 1628160 83 Linux
debian6-17-02-2012.img3 3416064 3807231 195584 82 Linux swap / Solaris
mount -o loop,offset=$((157696 * 512)) debian6-17-02-2012.img /mnt
I be interested to hear if/when anyone here gets hold of one.
I managed to get an order thru to Farnell at 8:15 this morning, don't know when it will come:( I'll keep you informed.
e-mail from Farnell today, expect delivery mid April :)
Yep, I got one of those too :) mine said 'early May' :(
The rapsberry pi saga seems to be going rather sour. Two thousands units have finally arrived in the UK but RS Components and element14/Premier Farnell will not/cannot distribute them until the Raspberry Pi until it has received the CE mark.
Surely the Raspberry Pi foundation should have know about these requirments?
I've given up on the idea of ever seeing one of these things until after the seond half of this year, by which time perhaps someone else will have brought an alternative to the market.
StanleyB
29-03-2012, 09:46
The CE marking than be done via self certification in this case. The unit does not have its own built in power supply and is not in an enclosure. An assembled PCB on its own is not required to have CE either. It is only required if it is in a case or some sort.
Stan's view is that of the Raspberry Pi Foundation too, but Element 14 and RS disagree and have refused to sell the boards without CE certification.
Hmmm maybe a small detail like that should've been resolved BEFORE they took on the distribution! Ho hum.
StanleyB
29-03-2012, 13:02
The EU made these CE laws so RS has to put up with it or be relieved of their sales deal. I am quite prepared to sell it if RS doesn't wan to.
sq225917
29-03-2012, 14:54
E14 and RS will be listening to their lawyers, or maybe there's other cards being dealt here!
The raspberry pi foundation does still aim to sell in the UK Eudcation market with devices in cases.
The EU made these CE laws so RS has to put up with it or be relieved of their sales deal. I am quite prepared to sell it if RS doesn't wan to.
Ah, yes, let's not forget the wonderful EU. Would that be the same EU that lead to the rasperry pi being manufactured in the far east in the first case?
As explained in this post: http://www.raspberrypi.org/archives/509
"I’d like to draw attention to one cost in particular that really created problems for us in Britain. Simply put, if we build the Raspberry Pi in Britain, we have to pay a lot more tax. If a British company imports components, it has to pay tax on those (and most components are not made in the UK). If, however, a completed device is made abroad and imported into the UK – with all of those components soldered onto it – it does not attract any import duty at all. This means that it’s really, really tax inefficient for an electronics company to do its manufacturing in Britain, and it’s one of the reasons that so much of our manufacturing goes overseas. Right now, the way things stand means that a company doing its manufacturing abroad, depriving the UK economy, gets a tax break. It’s an absolutely mad way for the Inland Revenue to be running things, and it’s an issue we’ve taken up with the Department for Business, Innovation and Skills."
Now you might say the raspberry pi foundation had been naive about these things, but I really wonder if they've even pointed the finger at the right culprit.
StanleyB
30-03-2012, 20:47
The import duty levy that importers have to pay to HMRC is not set by the EU. It is a local additional tax for the Treasury.
Reid Malenfant
30-03-2012, 20:53
The import duty levy that importers have to pay to HMRC is not set by the EU. It is a local additional tax for the Treasury.
Aye, anything over £15 attracts VAT (20%) if imported from a non EU country, anything over about £150 gets import duty slapped on top (about 4% if I remember right).
StanleyB
30-03-2012, 21:04
The actual percentage level of import duties varies from item to item.
Reid Malenfant
30-03-2012, 21:07
The actual percentage level of import duties varies from item to item.
While I'm assuming the VAT doesn't or shouldn't... Pray, do tell, I'm all ears/eyes :eyebrows:
StanleyB
30-03-2012, 22:00
Import VAT is 20% in the electronics field. The import VAT can be offset against the sales VAT if the business falls within that VAT agreement, but the import duty can't be offset.
The import duty levy that importers have to pay to HMRC is not set by the EU. It is a local additional tax for the Treasury.
Would this import duty exist if we were not in the EU? What were its rates pre- 1973?
Import VAT is 20% in the electronics field. The import VAT can be offset against the sales VAT if the business falls within that VAT agreement, but the import duty can't be offset.
VAT did not exist in the UK prior to 1973. It's a nightmare for any small business.
It seems to me that EU membership is not doing any favours for the raspberry pi foundation. And now I've got to eat cold pasties :steam:
Mark Grant
31-03-2012, 17:11
While I'm assuming the VAT doesn't or shouldn't... Pray, do tell, I'm all ears/eyes :eyebrows:
A link here about import duty:
http://www.hmrc.gov.uk/customs/tax-and-duty.htm#1
taken from the above link:
There are around 14,000 different classifications. The duty rate percentage for each may vary according to the country the goods come from. The average percentage is between 5 and 9 per cent, but it can be as low as 0 per cent or as high as 85 per cent....
What a nightmare with so many different rates of duty......
A list of all the codes can be bought from here for hundreds of GBP:
http://customs.hmrc.gov.uk/channelsPortalWebApp/channelsPortalWebApp.portal?_nfpb=true&_pageLabel=pageImport_ShowContent&propertyType=document&resetCT=true&id=HMCE_CL_001196
-
Reid Malenfant
31-03-2012, 17:20
What a nightmare with so many different rates of duty......
A list of all the codes can be bought from here for hundreds of GBP:
http://customs.hmrc.gov.uk/channelsPortalWebApp/channelsPortalWebApp.portal?_nfpb=true&_pageLabel=pageImport_ShowContent&propertyType=document&resetCT=true&id=HMCE_CL_001196
6512
That kind of figures :rolleyes:
Would this import duty exist if we were not in the EU? What were its rates pre- 1973?
VAT did not exist in the UK prior to 1973. It's a nightmare for any small business.
It seems to me that EU membership is not doing any favours for the raspberry pi foundation. And now I've got to eat cold pasties :steam:
I believe purchase tax was 33.3% on luxury goods at one point and vat just 10% when it was first introduced, falling to 8% a year later and vat is some what easier to work with even if we do have to eat cold pasties and squeeze into childrens clothes to avoid it.
Luxury Goods? In 1973, I only had enough Wilsonian pounds in my pocket for a warm VAT free pastie.
Every time I look enviously at a bit of hi-fi kit I cannot afford I just keep telling myself that at least I haven't given £20 for every £100 spent to those wastrel b'stards that run this country.
Mind you I've been well and truly stuffed by the great digital TV switchover scam when the bloody scart socket on my still perfectly serivceable analogue TV developed a fault instantly turning it in so much junk. :steam:
Wonder if I could flog it to Damien Hirst so he could do one his art installation thingies. You know, just splice it in two with a chainsaw and stick it a fish tank.
northwest
15-04-2012, 03:49
The first batch of Raspberry Pi computers are being issued to users
http://www.bbc.co.uk/news/technology-17703852
Mine arrived at work Tuesday morning. I put Debian “squeeze” image on the SD card using Win32DiskImager, connected it up to power, keyboard, etc. and booted it up. Surprise it all worked first time.
Sorry to drag this thread up from the past but has anyone here got one working with xbmc and a DAC? And is it any good?
I recently became aware of these units and was wondering if to have a dabble or not
Sent from my Nexus 7 using Tapatalk 2
Just ordered one from Maplins (type B), with the additional bits, at £69
Hopefully I can get it up and running as an SB player using SqueezeSlave...
http://www.squeezeplug.de/
...we'll see :eyebrows:
northwest
11-09-2012, 14:36
Just ordered one from Maplins (type B), with the additional bits, at £69
Hopefully I can get it up and running as an SB player using SqueezeSlave...
http://www.squeezeplug.de/
...we'll see :eyebrows:
That looks very interesting. I will just have to get one now! I was waiting for the Made in UK batch to show up on the RS site first though and might just hang on.
Everything from a command prompt, just like the olden days :lol: Great!
I've had one for a while, but not had the time to play extensively yet. I gave a very early version of the XBMC distro Raspbmc a quick try, but at the time USB dacs weren't supported, Will play some more once I've some spare time.
LittleTone
13-09-2012, 19:59
Hi Guys,
Anyone any ideas how to get digital output from a Rasberry Pi ?
Got it running Logitech Media Server using Squeezeplug; but would prefer
trying direct output into a DAC and see If I can dispense with the Logotech
Touch.
Would a USB sound card be the way to go ?
Regards
Tony
Hi Guys,
Anyone any ideas how to get digital output from a Rasberry Pi ?
Got it running Logitech Media Server using Squeezeplug; but would prefer
trying direct output into a DAC and see If I can dispense with the Logotech
Touch.
Would a USB sound card be the way to go ?
Regards
Tony
Don't you actually need 'SqueezeSlave' implemented for it to be a player?
My hope is that I can get the output to go via USB, but until mine arrives I'm just speculating...;)
LittleTone
14-09-2012, 11:45
Yes you do. Have been there and tried that.
Looking to get something bit perfect out; preferably by coax/toslink that I can connect to the DAC
Tony
stupinder
14-09-2012, 13:20
Eldest has his Pi arriving in a day or so...i will be coercing him into building something for me under the pretense that he is learneding :-) Ahhh, the joy of having bred slaves!
Mine arrived about a week ago, I bought the kit from maplins...
The maplins version comes with Raspbian pre-loaded on an SD card, so I was very quickly up and running, browsing the internet via the Midori browser...excellent!!! ;)
On issue however, no flash support for Midori, so my intention to use it for BBC iPlayer etc. was thwarted somewhat..
However...
RaspBMC has been developed as an OS to support XBMC on the Raspberry, and after a bit of configuration, and research, I now have the world's cheapest media centre...:)
Seems to work very well, although I may need to upgrade my wifi dongle, or connect via ethernet, as I had a couple of drop outs last night...early days, time will tell.
Tonight I'll try it with the Android XBMC remote app (free), which should remove the need for a keyboard...that'll make things a bit neater, it may also help the wifi dongle as they are effectively sharing the same USB port :cool:
RaspBMC has been developed as an OS to support XBMC on the Raspberry, and after a bit of configuration, and research, I now have the world's cheapest media centre...:)
Excellent - I tried a very early RaspBMC release which worked, but USB audio wasn't supported, so I couldn't get my Caiman to work.
The current RaspBMC version uses the new XBMC AudioEngine and there's a few settings in there you may wish to play with to make sure that it isn't changing the sample rate etc - especally the setting in advancedsettings.xml "<audiophile>1</audiophile>"
see: http://wiki.xbmc.org/index.php?title=AudioEngine
Excellent - I tried a very early RaspBMC release which worked, but USB audio wasn't supported, so I couldn't get my Caiman to work.
The current RaspBMC version uses the new XBMC AudioEngine and there's a few settings in there you may wish to play with to make sure that it isn't changing the sample rate etc - especally the setting in advancedsettings.xml "<audiophile>1</audiophile>"
see: http://wiki.xbmc.org/index.php?title=AudioEngine
Very interesting Keith, there are lots of possibilities for this little beast ;)
As my only USB DAC feed is occupied by my SB Touch I'm not that fussed about the USB audio out at the moment...but for future use this could prove excellent ;)
I'll have a look in advancedsetting.xml though, that sounds interesting :)
P.S. Cheers for the link, that looks very useful...
Doh!...my Pi is already 'legacy' :doh:
http://m.techcrunch.com/2012/10/15/raspberry-pi-mini-computer-now-shipping-with-ram-upgraded-to-512mb-from-256mb-same-tiny-35-price-tag/
...typical!
Actually for the purposes I'm using it (XBMC media centre) I doubt I'd need the extra RAM, it seems to work fine as it is.
This extra RAM might make a difference for more generic purposes, particularly for Chromium etc.
Anyway at £30 a go I'll probably end up with a few...;)
I've said it before about early adoption, you will pay for it...at least in this case its not big bucks. :)
I've said it before about early adoption, you will pay for it...at least in this case its not big bucks. :)
Bleeding edge mate...;)
It's a shame that Raspbmc only has flaky alpha support for USB dacs (even that seems to have been removed in Release Candidate 5) - that's all that's stopping me using my Pi to replace my old HP tower that serves as my music streamer.
It's a shame that Raspbmc only has flaky alpha support for USB dacs (even that seems to have been removed in Release Candidate 5) - that's all that's stopping me using my Pi to replace my old HP tower that serves as my music streamer.
...just a matter of time I think Keith, we're still in the early stages with the Pi :eyebrows:
aquapiranha
16-10-2012, 17:20
Hmm I never realised it could run XMBC but does it do remote too?
Hmm I never realised it could run XMBC but does it do remote too?
The short answer is yes...
http://www.raspbmc.com/wiki/user/configuring-remotes/
...but you'd need an infra red dongle to use a proper remote, although if you configure it as a webserver you can use the XBMC android app!
However it appears to be a little bit flakey, more than three successive left keys send the menu bar into a rotational frenzy...shame :doh:
But as I said earlier it's early days...and it works fine via the keyboard :)
aquapiranha
16-10-2012, 18:35
Thanks!
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