Rockbox Player - Project to design and build a Free/Open hardware audio player

[torne]

I would love to put something like that in my car, with one catch, I would want the screen to be external.

The screen there is external, effectively; it's just been put in the same box. You can put it further away, I'm sure. (though there may be bounds on the cable length). There certainly exist boards with various kinds of TV-style video out that would attach to your in-dash screen.

And yes, porting to the device you already have is a possibility, if it's suitable; follow the same process as any DAP port

[bobc]

I decided running rockbox would be a waste, I'm working on getting linux going and then rockbox as an app so I can have storage on the network

I think that Rockbox/App on Linux makes a lot of sense for mini2440, I will have to look into it. I suspect it will be easier to create an App than a hardware port, and much more useful in the long run. Getting access to USB and network drivers etc via Linux is a big chunk of work saved. The Chumby could also be a suitable target for Rockbox/app.

The Lyre project is somewhat stalled at the moment, we can continue with mini2440 even though it is not suitable for portable player, or develop/adopt an alternative platform, of which there are several potential chips but no board designs yet. Cortex support is also a sticking point, since many of the new chips use this architecture.

So I think the way forward is Rockbox/app for mini2440.

I would love to put something like that in my car, with one catch, I would want the screen to be external.

I already have an in-dash screen that runs off a composite video cable, and I'm feeding that with a Western Digital WDTV. (it has S/PDIF and reads any HD).

There is a VGA adaptor board for mini2440, but no composite video or SPDIF, so I can't think how that can be done.

[casainho]

EDIT on 2010.04.27:

THE BOARD FROM OPENDOUS:







Source files, schematic in pdf and more details about the plastic enclosure: http://code.google.com/p/propendous/

Matt wrote:

I just completed the first revision of the board and am about to
send it off for fabrication.  I managed to fit the following into this
hand-held 77x61mm 2-layer board that fits the Hammond 1553B_BAT case:
- 0.1" 40pin Header with all usable signals exposed
- 0.1" ARM JTAG Header as well as Serial-JTAG Header
- 2 LEDs (Power and Debug/USB Host)
- microSD (captive) for system files
- SD (external) for user files
- DDR SDRAM
- USB Hosting
- USB Device
- Headphone Jack
- Line-In Jack
- Microphone
- RCA Video Jack
- 2 LCD connectors - 1.8" and 2.4"
- Touchscreen Controller for the 2.4" LCD
- Accelerometer
- 2mm Boot Jumpers

 Most of the components are optional.  I hope to start prototyping
later next week.

THE BOARD FROM JOHN COOPER:

John Cooper is also making a board for imx233, and he have already good images of it: http://people.redhat.com/~jcooper/projects/nutshell/wip/0.01/

I think this two boards will blend in just one. We are all cooperating to make a cheap DIY board based on imx233 :-)

The objective is that the hardware can run Rockbox and Linux, thinking in the Rockbox as being an app on Linux :-)

---

Me and Bob, we had being in talk with Matt from Opendous. We decided to pay Matt for design a module board with ARM9 + SDRAM + uSDCard.

We decided for imx233 (the same Chumby uses) because it have integrated audio dac.

The module we plan will have imx233 + SDRAM + uSDCard + power + 1 LED.

We plan to make a "nano" DAP, in the sense of being simple, cheap, DIY. After having the module, we will connect to it a Lithium battery of 3.7V. Firmware will be stored on uSDCard as user files. Some buttons will be wired to module board. A audio jack for audio out will also be wired. Also a cheap LCD with few wires. Finally we will put it inside a plastic enclosure (I plan to print my own).

We defined already the module functionalities and size. Matt will start design next week and finish. Other week for boards be done. Another week for then arrive at our homes.

I think this project must be a kind of DIY. Like Arduino and RepRap 3D printers which are my both projects references. Both of them are Open Source and have many sellers/online shops :-)

[squonk]

I'm very happy to hear something new about Lyre project!
Some questions about the recent update.

1) casainho talk about Rockbox as being an app on Linux: this is reported also in the ideas list of Google Summer of Code 2010. How long can take to developers to realize a this "porting"?

2) With the new board that seems to be realized very soon, what about sound quality? We can expect a kit with a decent sound?

3) With the new palyer it will be possible to store the audio files on both HDD and SD memory card?

Many thanks!

[casainho]

EDIT on 2010.05.19:
And now John, updated his board for also the IMX233 ARM9 and wrote this message:

Hi all,
   I've reworked/augmented the design somewhat, tightened up the core board layout, and added the mating user interface board to complete the self-contained portable audio decoder.

schematic/mechanical (PDF)

core board:


user interface board:


The core board is still usable in standalone/embedded scenarios (without mating interface board) as a second micro SD connector has been added for application use.  The modified debug port can be used for basic off-board control rather than interfacing via the full expansion connector.

But the primary target has been a self-contained audio player. To that end the interface board adds a low power transreflective graphic display, UI navigation direction control, rotary jog encoder, and discrete tact switches.  A full sized SD card slot is also provided.  I've located base and interface board
components to maximize stacking density and was still able to reclaim over 5% of base board area.  The updated schematic includes a mechanical drawing of the intended enclosure for reference.

Further size reduction is possible to some degree but would involve changing the 3.5mm audio jack to a 2.5mm version, use of a lower capacity (smaller) battery, and dropping the standard size SD slot.  For perspective, the standard SD connector alone is nearly half of the size of the 40x56.8mm core board.

Sans a few minor tweaks such as potentially adjusting switch mounting locations for mechanical optimization, I think it is near complete.  Feedback and suggestions however are welcome.
Even after layout validation another spin will be needed using 0.5~0.8mm thick laminate as standard 1.6mm stock wastes considerable volume in a design of this size.

Thanks,

-john

EDIT on 2010.05.18:
Matt just received the PCBs (to fit on this Hammond plastic enclosure), and we will be 3 developers assembling it, me, Bobc and Matt Opendous.



I think Matt have more PCBs, if anyone want one, please ask him. Source files for schematic, board (in KiCad) and fabrication are here (Open Hardware project).

Matt told us on e-mail: I will be prototyping a board tomorrow and will film the process and
post on YouTube.

Here is video about IMX233: Get Started: Freescale i.MX233 Multimedia Applications Processor

And I hope to receive my PCB and components in a week :-) -- Matt sold to us one kit (PCB + components + shipping) for $50 :-)

---

I'm very happy to hear something new about Lyre project!

I am happy too :-)

Some questions about the recent update.

1) casainho talk about Rockbox as being an app on Linux: this is reported also in the ideas list of Google Summer of Code 2010. How long can take to developers to realize a this "porting"?

I don't know. Board will be able to run Linux. It's Open Hardware project, and board have the same size of Arduino pins for attach a secondary board... we hope that users will be able to hack it and help us to get Linux and Rockbox running on it ;-)

2) With the new board that seems to be realized very soon, what about sound quality? We can expect a kit with a decent sound?

I don't really know. imx233 have integrated audio codec and we will use it for start. Later if we need more quality, we can use any better external codec IC and electronics circuit.
The Chumby uses imx233, so maybe the ones who have one Chumby can tell about the audio quality.

3) With the new palyer it will be possible to store the audio files on both HDD and SD memory card?

Actual board have 2 memory cards. 1st: an uSD card to hold Rockbox or Linux firmware and from where imx233 boots. 2nd: and SD Card to hold user files.

An HDD? I don't know, maybe if someone want to add it... it's Open Hardware, ready to hack :-)

Board have USB Host, which means it can read any external USB flash disk/hdd.

[casainho]

Would that be the Chumby one or Classic? Will it be able to have wi-fi from the board or will it need a secondary board for wi-fi? If it is the Chumby one the 2watt sound will be in mono or stereo inputs. Does it have just stereo inputs?

See the schematic (in PDF files or KiCad files) and try understand/compare with Chumby version that uses the same i.MX233 ARM9.

[john.cooper]

I would love to put something like that in my car, with one catch, I would want the screen to be external.

I've come to that realization several times myself.  IME in-dash
audio decoders tend to miss the mark UI-wise.

Locating a screen remotely is fairly straightforward.  But I'd
almost want to situate it quite close (but not obscuring) the
normal field of view while driving.  At least in my usage I
find myself frantically multiplexing between the road and
the economized display down/over there which is neither
safe nor a pleasant user experience.  Having a display either
on the dash or just below (above the instrument cluster)
would seem to work far better.  Width is probably easier
to accommodate in such a location vs. height so it could as
well be a secondary display.

For an input device I can make a case for either a wheel
mounted control and/or a handheld remote.  The in-dash
front panel buttons tend to be limited to setup operations
in my usage if not nearly ornamental.

I already have an in-dash screen that runs off a composite video cable, and I'm feeding that with a Western Digital WDTV. (it has S/PDIF and reads any HD).

I would love to upgrade/replace it with something running rockbox, but I'd need the same integration I have now.

Any way to get rockbox with S/PDIF out and an external screen? (besides a port of Rockbox to WDTV, which I doubt would be trivial and popular)

This external screen is driven by an NTSC signal?  If so
what effective resolution does it achieve for rendering text?

-john

[casainho]

I got the SDRAM working! It's running at 133MHz. Initially I started to run it at 96MHz. I used code the fill the full 32MBytes SDRAM with 1 and tested, again with 0 (I used volatile variables to hold the values, so the values are for sure written and readed from SDRAM).
Matt Opendous also have his SDRAM working :-)

So, the SDRAM runs at 133MHz and the ARM9 core runs at 454MHz!

So, this great DIY board works and next we will put the 2.4'' color LCD working. After the buttons and audio connector. We may also start porting Rockbox to it. And I am sure some of us will also try Linux and Android on it :-)

I also want to put my 3D printer working again, and try to design and print a plastic enclosure for this "Digital Lyre" :-)


--------------------------------------
Edit:
Today I got the Hammond plastic enclosure. I placed the board on it and the Lithium 3.7V 900mA AA size battery:


I think we need to use instead printed enclosures, because:

- that Hammond enclosure cost 9€ (including VAT), a printed one could
cost 3€ or less;

- there are some free space on case, with a printed one we can design
it to have the smaller as possible;

- on the Hammond we need to make a big square hole on it for the LCD +
more holes for buttons + holes USB and audio. On a printed enclosure
there is no need to open the holes, so, much less work!

--------------------------------------
After a few days, I have 2 boards blinking their own LED, and firmware code is on the uSDCard - i.MX233 is booting from the card:

This is the back side of the board. SDRAM is not assembled yet.


This is an image of my oscilloscope shows the time i.MX233 takes to boot. The channel 2 is VDDIO_3V3, showing the start o boot, and channel 1 shows the uSDCard clock signal. So, i.MCX233 boots and takes about 25ms to start reading the firmware file stored on uSDCard.

The current blink LED code is heavily based on Chumby -- many thanks to Chumby hackers :-)

Right now, me, Bob, John and Matt, we are the only ones that worked for this board - the code is on SourceForge Lyre SVN.

--------------------------------------
Edit:

I assembled the 2 boards, a minimal assembly that permits boot the imx233 and blink the LED. Right now one board is shutting down, some problem on imx233 internal DC-DC, and I am getting help on FreeScale forum.



--------------------------------------
I got my board and components, plus the ones for Bob. I will assembly both boards and send one to Bob :-)

I took 2 pictures shoing the board and the imx233 (not assembled):





For me, this board is art. This SoC i.MX233, ARM9 @ 454MHz, booting from uSDcard, having a secondary SDCard, having LCD controller and audio output and input, lithium battery charger, is the SoC we were waiting for this project! And it's very important because it is LQFP of 0.4mm pitch, and not BGA, meaning that we can DIY soldering.
i.MX233 is from FreeScale, but FreeScale bought Sigmatel (many MP3 players on market with SigmaTel SoC), and this i.MX233 looks like to be a Sigmatel SoC, because it boots only images files of "sb" type. The is one utility for Linux to convert images to "sb" type, and I got this output when seeing version on the utility:

cas@cas-laptop:~/Documentos/propendous$ ./elftosb2 -v
elftosb 2.2.1
Copyright (c) 2004-2007 SigmaTel, Inc. All rights reserved.

[cohe30ve]

hi all
i am new in i.mx233 and i want to start it for my new project .
my project have a color lcd display .

can i use color lcd with this i.mx233 ?
i can`t access to your pcb and schematic files , please someone email it to my email :at89c4051@yahoo.com

and last :
how can i work with this device in micro controller mode like (at91sam9263+IAR).
i want to turn on a led (work with GPIO) for my first project , is it a good way to learn to use i.mx233 ?
==> please help me . i cant find someone that worked i.mx233 .... 

[friendlyzookeeper]

You should be able to hit some forums, but you can start with some tutorials

http://wiki.ladyada.net/chumbyhackerboard

forum for chumby....

http://forum.chumby.com/viewforum.php?id=20 

and you can purchase a chumby hacker board from....

http://www.sparkfun.com/commerce/product_info.php?products_id=10106

[cohe30ve]

so thanks for your reply .
but i dont have any device that use imx233 .
and i cant buy chumby because i am form india ... .
please offer link to download 2 layer pcb for it ... .
so thanks.

[casainho]

New times

Last time I were stucked with the idea of using color LCD, and since I am not able to produce a PCB and solder it, I didn't went further. Now I changed my ideas, mainly because now I see people "aligned" with me (or me with them ?).

1st. People need to share art, and in NY people is creating "networks" of sharing using cheap USB flash drives -- I always wanted a device to play music and easily share the art files;

Some artist, like Binärpilot, which I love, says about their art/music files: "share them with your friends, give copies of them to strangers"

2nd. Online shops like www.Etsy.com have users/clients that buys handmade electronics and art pieces.
DIYers are growing and people likes a lot electronics and art, the example of 3D printing robots like RepRap and MakerBot.

My plan is now to continue use IMX233 ARM9 board @ 454MHz:

and wire to it a few buttons + battery + cheap b/w LCD. Then design and 3D print the plastic enclosure. Finally sell it on www.Etsy.com, running Rockbox and including Rockbox source files plus all others like schematics, board and 3D design of enclosure. Also full on music with Creative Commons licenses like this album from Binärpilot:

[casainho]

From the last post, I see the board you're working now with has a USB host port, this is for inserting pendrives, correct? Great idea. Having a SD/MMC slot is great too.

That board were done to be a general board for Linux and so have all that things. As for Rockbox, I just need as minimum at working the SDCard, LCD, buttons and output audio DAC -- so I will port Rockbox for that.

One small consideration though... if I understood correctly, you're not going to use a color LCD, correct? What's the resolution that might be used, do you have any idea?

Cheap (6€ including shipping on Ebay) Nokia 84X48 b/w LCD -- because it's cheap, easy to source and mainly because it's very easy to solder the few wires.
I have "good" color LCD but I can't put it working because of a missing electronics board. I need to move on, so for now I will use that "crap" LCD BUT what I am looking for is audio and not image/video.

Greetings from Portugal - I hope local forum posts are cheaper...

Yeah, I am from Portugal.

[coacharnold]

Ok Guys,

    with respect, I don't ever post here just follow this thread. But, this conversation has perked my funny bone.  Rockbox is fantastic to start out with.  The guys on this thread are doing an amazing job developing an open source piece of hardware that will run Rock Box and be a great music player.  If network support is so important lets all go over to the Rockbox Android forum and have this conversation.

Thanks for all the hard work being done here ..... its looking amaizing

Tim

quick question .......   whats the quality of the D to A on this thing as it stands now. Has there been discussion on making this things sound output be better than any of the current store bought players .....   ( HiFiMan)  ?

[casainho]

quick question .......   whats the quality of the D to A on this thing as it stands now. Has there been discussion on making this things sound output be better than any of the current store bought players .....   ( HiFiMan)  ?

The ARM9 IMX233 SoC have it's own internal DAC, it's a cheap and simple solution however I don't know if it's good or not -- but it should be, I hope. Being OpenHardware the board and having expansion header, should be easy to add an external DAC and components for better audio quality (if someone wants to)