Free/Open digital portable audio player

[casainho]

UPDATE: New page on RockBox wiki was started about this idea, please contribute: http://www.rockbox.org/twiki/bin/view/Main/RockBoxPlayer

Hello! I am new to Rockbox and full of ideas...

Why not start designing a Free/Open digital portable audio player? - I remember to see others that rely on MP3 IC decoder and a 8 bits Atmel AVR microcontroler. Looks like that now we can buy a 32 bits AVR32 Atmel that runs Linux - with this we don't need MP3 decoder IC and can have Rockbox (as an application on linux kernel) do the decoding of MP3, OGG, Flac, etc...

My guess is that we just need processor AVR32, RAM, DAC, LCD, BUTTONS and any COMPACT FLASH (or other) for store files.

USB and audio decoding done in processor! A Player that plays almost any audio codec and that can read from flash cards or HDD!! and that acts as an host - meaning that would be possible to copy music from player to player, nice to share music with friends.

I believe that today players are complex in software because of need to protect DRM music and things like that. But times are changing, there are a lot of free music over internet that should be shared, for example www.Jamendo.com site that provide music with CC licenses and a lot of artists are sharing their own music on theirs  own sites!!

[saratoga]

Why not start designing a Free/Open digital portable audio player?

Because that would be expensive and probably not result in a very attractive player compared to existing commercial ones.

with this we don't need MP3 decoder IC and can have Rockbox (as an application on linux kernel) do the decoding of MP3, OGG, Flac, etc...

Rockbox is an operating system, not a linux app.  Only the sim works with linux, and its not really usable as a player (yet).

USB and audio decoding done in processor! A Player that plays almost any audio codec and that can read from flash cards or HDD!! and that acts as an host - meaning that would be possible to copy music from player to player, nice to share music with friends.

Rockbox already does this except for the USB host, and I don't see how having different hardware would help any of this.

[casainho]

Why not start designing a Free/Open digital portable audio player?

Because that would be expensive and probably not result in a very attractive player compared to existing commercial ones.

But we could win somethings with this player tailored by us - for example, have all hardware working and perfect rockbox port, quick and easily done!!

with this we don't need MP3 decoder IC and can have Rockbox (as an application on linux kernel) do the decoding of MP3, OGG, Flac, etc...

Rockbox is an operating system, not a linux app.  Only the sim works with linux, and its not really usable as a player (yet).

Ok, I understand, I read somewhere in site that Rockbox should be made as application, maybe because that are portable devices like phones that could run RB. Anyway, its possible to made a native port of RB for AVR32 since there are a free software GCC-AVR32 for him - thanks Atmel ;-) :-)

USB and audio decoding done in processor! A Player that plays almost any audio codec and that can read from flash cards or HDD!! and that acts as an host - meaning that would be possible to copy music from player to player, nice to share music with friends.

Rockbox already does this except for the USB host, and I don't see how having different hardware would help any of this.

What I am trying to say is that now we can have a lot of portable digital music player made in software, because now we have fast and powerful processors, not like in the past that should have also MP3 IC decoders and USB ICs.

Maybe I am dreaming - a lot of what I do ;-) :-)

[casainho]

I found for seel AVR32(AT32AP7001) at Digikey for 20$ - http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=AT32AP7001-ALUT-ND

So for $20 we get:
32 KB on-chip SRAM, .... Peripherals include a 16-bit stereo audio DAC, ..., 480 Mbps USB 2.0 ...

For the hardware player we would just need the AVR32 ($20) + LCD (Nokia LCD $5) + BUTTONS ($2) + BATTERY ($10) + COMPACT FLASH CARD ($25).

I have found one player as I thought :-) - http://dspdap.sourceforge.net/index.html

The concept is the same however that player is old and uses a TMS320C55x DSP from Texas, which don't have any GCC version for it :-(

The guy from Daisy MP3 sells It's own kits for soldering and they are not expensive. Also there are Makezine and others that sells projects already assembled...

There are others players that uses IC MP3 decoders:

Daisy MP3 - http://www.teuthis.com/html/daisy_mp3.html
The Sakura, The World’s Simplest Open Source DIY MP3 player! - http://www.teuthis.com/html/mmc_mp3.html
Yet Another MP3 Player - http://www.myplace.nu/mp3/

[saratoga]

Why not start designing a Free/Open digital portable audio player?

Because that would be expensive and probably not result in a very attractive player compared to existing commercial ones.

But we could win somethings with this player tailored by us - for example, have all hardware working and perfect rockbox port, quick and easily done!!

Yes but because you've moved the complexity from software development to hardware development.  A better approach would be to simply start a port to an mp3 player that uses mostly documented hardware.

Ok, I understand, I read somewhere in site that Rockbox should be made as application, maybe because that are portable devices like phones that could run RB. Anyway, its possible to made a native port of RB for AVR32 since there are a free software GCC-AVR32 for him - thanks Atmel ;-) :-)

Yes but it would probably not work as well as players using an established arch like ARM.

What I am trying to say is that now we can have a lot of portable digital music player made in software, because now we have fast and powerful processors, not like in the past that should have also MP3 IC decoders and USB ICs.

This is true of many (most?) of the hardware platforms rockbox already runs on.  If this is what you're trying to say, then my response would be that you should buy a Sansa and develop for that.

[casainho]

But we could win somethings with this player tailored by us - for example, have all hardware working and perfect rockbox port, quick and easily done!!

Yes but because you've moved the complexity from software development to hardware development.  A better approach would be to simply start a port to an mp3 player that uses mostly documented hardware.

I think you didn't understand my point. I think that we should have simple hardware, as company's try to do, to have cheap hardware. When I said have all hardware working, because If we design the system so we know how It works!!

Ok, I understand, I read somewhere in site that Rockbox should be made as application, maybe because that are portable devices like phones that could run RB. Anyway, its possible to made a native port of RB for AVR32 since there are a free software GCC-AVR32 for him - thanks Atmel ;-) :-)

Yes but it would probably not work as well as players using an established arch like ARM.

Why do you say that?? - The RB works with Assembly and GCC-ARM, right? AVR32 works with assembly and GCC-AVR32 - so It's the same. The advantage, is that for buy a portal player as Sansa uses we can't get one in units but for AVR32 we can get one unit for $20 and all the information about It and Free Software tools for build and debug!

What I am trying to say is that now we can have a lot of portable digital music player made in software, because now we have fast and powerful processors, not like in the past that should have also MP3 IC decoders and USB ICs.

This is true of many (most?) of the hardware platforms rockbox already runs on.  If this is what you're trying to say, then my response would be that you should buy a Sansa and develop for that.

Eheh - I have a Sansa and I am very happy ;-) :-) But Sansa e200 can be discontinued or company can change firmware/hardware and not be possible to make RB working, as It don't work on others hardware, like Zune.

Okok, to resume: Now we can buy cheap powerful processors in single units with almost all peripherals included like DAC and USB, we can make an cheap and open player maybe by us, for us, and not have the need to make reverse engineering of hardware and software of players in market.

[Bagder]

Why do you say that?? - The RB works with Assembly and GCC-ARM, right? AVR32 works with assembly and GCC-AVR32 - so It's the same. The advantage, is that for buy a portal player as Sansa uses we can't get one in units but for AVR32 we can get one unit for $20 and all the information about It and Free Software tools for build and debug!

Ok, let's assume you go with an Atmel AVR (although I would rather say you should go with an Atmel ARM (if you must use Atmel) just because it would mean less work).

How on earth are you going to manage to create a small, usable and working device with a fine color LCD, storage space and buttons for 20 USD?

In fact, check how ridiculously low the Sansa e200 series is priced these days and when you start looking at the cost of flashes, of LCDs, of boxing etc it really is very very hard to come even close to their prices until you have quantities similar to theirs.

So, the real-world facts are that when you build your own player, it will be better documented sure, but it will be MUCH more expensive and most likely it will also be bulkier and uglier and we'd have to spend a life-time fixing hw-related bugs.

I think you're overlooking all the problems with HW-design and HW-development and a lot of other things that enter the scene when you start making physical devices.

But please, don't let all of us negative whiners stand in your way. Please prove us wrong. Make a 20 USD open device and we will absolutely love you! I hereby promise to buy more than one of those units.

[JeoL]

I can understand that RB developers do not want to invest time in developing a player with open hardware, but I don't see why every attempt to do should be shot down it it's cradle.  

It will probably be expensive relatively to mass-produced units yes, but I think it's doable if you aim for making a niche product for enthusiasts. A first step would be to gather those with knowledge of developing hardware, and start drawing schematics, settle for a pcb design and start investigating how expensive things will be (or whatever... I dont know! ^_^)

A (quick?), easy, lazy and expensive solution might be to use the openmoko phone, and start to work on "rockbox as an application". But then you'd also have a phone. Anyways, their mailing lists could be a place to ask for advice and information on how to best prepare a deal like theirs with FIC.

Just my 0.02 €

Edit: Eh, Bagder beat me to writing first positive post =)

[casainho]

I can understand that RB developers do not want to invest time in developing a player with open hardware, but I don't see why every attempt to do should be shot down it it's cradle.  

I imagine that are developers in RB that works with hardware, that understand hardware.

A first step would be to gather those with knowledge of developing hardware, and start drawing schematics, settle for a pcb design and start investigating how expensive things will be (or whatever... I dont know! ^_^)

We can take ideas or direct copy hardware parts from players that we already know. There is Open DSPdap for that, for example.

I agree with Bagder but Sansa and others simple audio players (not mention video players) are getting really cheap and that MUCH more expensive means a relative total difference, I paid 100 euros for my Sansa and I would pay 200 euros for an Open audio player that work with RB.

But maybe this is not the right place for looking at an Open hardware audio player. I started talking with guy at DSPdap, maybe It will be easy to work together with some group of people that is already working on that kind of hardware. But I think that hardware should support RB!! ;-) :-)

Another option could be RB give some space to people that likes hardware to start build that player, for enthusiasts. There are a lot of knowledge about hardware here in RockBox that could be used!

[Bagder]

I paid 100 euros for my Sansa and I would pay 200 euros for an Open audio player that work with RB.

200 Euros could possibly be the price you'd sell these units for once you have developed something more or less stable, but you'll have to spend a lot more over time while developing this and someone is going to have to put up a lot of money for initial investments for design, packaging, PCB, producing and more. That's why open source HW is much harder. You need real money to pay for all the physical stuff that need to be put together and shipped. Spare time and skills are not enough.

But maybe this is not the right place for looking at an Open hardware audio player. I started talking with guy at DSPdap, maybe It will be easy to work together with some group of people that is already working on that kind of hardware. But I think that hardware should support RB!! ;-) :-)

Right, Rockbox is a software project and we're mostly software guys here (even if many of the guys understand and work a good deal with electronics and hw as well). To get a good team of HW designers to join up, you surely will need to hunt elsewhere (too).

But indeed, I'm sure lots of Rockbox hackers will assist with advice and ideas on what to put in such an open player... A first idea would be to not use any DSP! ;-)
 

[casainho]

... you'll have to spend a lot more over time while developing this and someone is going to have to put up a lot of money for initial investments for design, packaging, PCB, producing and more. That's why open source HW is much harder. You need real money to pay for all the physical stuff that need to be put together and shipped. Spare time and skills are not enough.

I understand but at the same time we have examples of Daisy MP3 selling at Makezine - http://store.makezine.com/ProductDetails.asp?ProductCode=MKMP3KIT
Maybe we can find someone interested in assembling and selling the player.

But indeed, I'm sure lots of Rockbox hackers will assist with advice and ideas on what to put in such an open player... A first idea would be to not use any DSP! ;-)

After you said Atmel ARM, I saw that a AT91SAM7S32 cost £3.91 in Farnell :-)

Is that possible to have one page in twiki for resuming ideas for this project?

[scharkalvin]

I too had the idea of an open hardware player, and I looked at the AVR32 as well
(BTW there is a very nice development platform for this that sells for $69-$100).
The avr32 is simply an all in one chip, but there are arm chips like this too
(Philips makes one that is very similar and made for media players).

The real advantages of an open hardware player vs porting to an off the shelf player is that it won't get discontinued once Rockbox is ported to it, and ALL the documentation would be available so the port would be as good as it could be.  The major disadvantage would be cost, since you'd NEVER be able to make enough of them to lower the price to match what Sandisk, Toshiba, etc can do.  Also there are more open software developer types out there then hardware.

Still, wouldn't it be nice to have a Rockbox platform that would be as long lived as PC's have been (and as well documented!).  

[casainho]

I too had the idea of an open hardware player, and I looked at the AVR32 as well
(BTW there is a very nice development platform for this that sells for $69-$100).
The avr32 is simply an all in one chip, but there are arm chips like this too
(Philips makes one that is very similar and made for media players).

scharkalvin, do you want to join forces and start studying the idea? - for me this would be a great investment for my technical formation.

[scharkalvin]

At this point I'm not good for much more than ideas.
I wish I was good at cad software for schematic capture and pc layout.
THAT is CRITICAL to getting a design going.  If someone gets a wiki page
going, I'd be happy to post some hardware ideas, links to documentation
I've found, etc.  You'd need someone with the CAD skills to actually get the
design to the point where you could start ordering PC boards and stuffing them.
(not to mention surface mount soldering skills ....)

[casainho]

At this point I'm not good for much more than ideas.
I wish I was good at cad software for schematic capture and pc layout.
THAT is CRITICAL to getting a design going.  If someone gets a wiki page
going, I'd be happy to post some hardware ideas, links to documentation
I've found, etc.  You'd need someone with the CAD skills to actually get the
design to the point where you could start ordering PC boards and stuffing them.
(not to mention surface mount soldering skills ....)

Well, I can get one wiki for this project, however, I think that It should happen here at RB! - It would be good for both projects, both can win. To who should I ask for use RB Twiki?

I work in a company that makes lights for automobiles with LEDs - http://www.plurirede.pt/ - we make PCB drawings, I can get some ideas with my friend at work. We normally buy 4 or 8 units PCBs for prototypes from FAST PCB PROTOTYPES companies.
We also have a machine for drill PCBs... I will be able to take some ideas for project.

But I am sure that we will find someone that does that job as profession and that will do that part of project.

I already made some simple electronics projects in group, wich I just did programing and not PCB drawing. You can see more here at my homepage:
http://www.casainho.net/tiki-index.php?page=Electronics