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

[casainho]

why not gp2x?
Because it uses some MagicEyes processor which could have a support problem.
Chumby uses freescale which definately has better support. Appnotes and Linux BSP is available. Shematics & Layout available.

Nice to know that we don't loose open documentation, Appnotes, schematics and availability, when changing from Atmel to Freescale

So, chumby don't have some things we were looking for Rockbox Player, as USB 2.0 High Speed, SD card and tactile buttons, but have the basic hardware for a functional audio player: USB connection, flash memory for music files, audio out, display and buttons(in form of touchscreen??).

Roger, I wait now for the TWiki page update. Maybe you can create a new prototype version, based on Chumby hardware?

[spark]

good it does not have everything, else we would have nothing to do 

i suppose instead of creating a new version we just modify V1 page.

[casainho]

good it does not have everything, else we would have nothing to do 

i suppose instead of creating a new version we just modify V1 page.

We will need to change the hardware on Chumby or not? If not, It will be a port for Chumby - a port with objectives of build the Rockbox Player - and ok, V1 release can be for the Chumby

Sorry I haven't been around lately, been ill and taking a lot of doctors testing. So casainho, did you understand what you did to turn on and off the led lights? What switches was involve and how much current that went though? Have you tried any other led lights or switches? Most of the time you have to follow the schematics. Hope you get your board ready soon for the proto finish.

Talk to you all later, when I'm feeling better.

All ok with LEDs, they did flash as pretended.
Good luck

[spark]

of course, we have to do hardware design. Enough of talking from my side. I will only post when i have done some work on V1.

[1ny0urfac3]

I'd be very interested to see support for compact flash internally.  that would really sway me to one of these things

[casainho]

I'd be very interested to see support for compact flash internally.  that would really sway me to one of these things

I am being busy with another simple project than Rockbox Player -- I am waiting for my summer holidays to continue working on this project, I want to make my prototype working. I am getting now a lot of knowledge in my actual project, in which I am applying knowledge I learned when working on Rockbox Player

[casainho]

Hey guys, I was wondering if the game boy advance would be a good platform for the dyi project. Low cost arm7 with buttons and screen, the sp has backlit. The media could use a R4 or EZ flash with conjuction of the micro or mini SD cards.

I am being thinking about this project. The main problem for this project is the lack of interest from "base" developers of Rockbox on a DIY hardware.

Today is very simple to have a hardware with a MCU that have firmware which is downloaded by USB - very easy to hack firmware.

I say DIY hardware because it must be like that, the first ones should be a higher energy investment from developers, developers can't expect a hardware with perfect LCD, with perfect size, with perfect MCU, etc... - instead developers that likes hardware should be proud of having a own made raw hardware.

Looks to me that at Rockbox there is not developers of hardware, just firmware.

Recently I am working on a project with an MCU of 8 bits with USB, my first experience on USB. All is going well because I found another person that believes on the project and is working a lot in hardware, he did draw the actual schematic and is drawing now the PCB. I bought a development board, made some tests on hardware and made firmware, mainly drivers. I found another person to work on PC software. Alone I couldn't do this my actual project, is very important to have a group of people working.

For this project RockboxPlayer, I alone can't program, make working, reuse, things like USB, FAT drivers, ATA drivers, etc... because I have none experience on that. But I can make drivers for audio IC, LCD, buttons, etc, and helping testing. So, It's impossible to put a prototype working - firmware is much important on this project, but there is none Rockbox firmware developers wanting to work on this project - Free/Open hardware audio player and recorder, for use with RockBox firmware.

I didn't forgot this project, I will not. I am having experiences with others projects on things like DataFlash memory, I am reading about FAT32 firmware libraries for MCUs, USB firmware libraries, etc -- when I found people that wants to work on this project I will happy work together, however now I don't believe on people that says want to build a hardware with LCD of big size, big colors, the perfect LCD, the perfect size, the perfect MCU, etc.



 

[casainho]

Hello

I am back to development, after some interruption to clean my head of this project. While then I started the Bicycle LED POV project and ended up by learning a few things that will help me on Rockbox Player, mainly on the DataFlash memory, USB, FAT32 and SD card.

Shift on development approach:

I will continue to use the Olimex development board. I will not use NAND flash. I will use instead the DataFlash to hold the Rockbox firmware and the SD card to hold audio data files. Programing of Rockbox firmware will be done using SAM-BA with USB connection, on GNU/Linux, and debug using the serial port and LEDs.

I will avoid using NAND flash and USB, I tough in using it initially. Since I can format and write on PC the SD card, I don't need USB for having this hardware working with Rockbox - I must simplify the development.

My very first task will be building the AT91 bootstrap that will initialize SDRAM, DataFlash and some others peripherals, load the Rockbox bootloader from DataFlash to SDRAM and jump to it.

Rockbox bootloader will initialize the system, the kernel, the LCD, the buttons, the SD card ATA driver, mount the FAT file system on SD card, read the Rockbox firmware from the files on FAT file system and finally jump to it.

The very first thing will be having a flash LED code, after doing drivers to have LCD working, after the buttons and finally the ATA for SD card.

[casainho]

Sparkfun has some really good info on most of the hardware. Look under breakout board example breakout >Micro SD/MMC card and go to the end of the page and there will be schematics and kronos and other sites that will be very helpful with example codes and info on fat16. I would prefer fat32.

FAT32 drivers are already in Rockbox source code. FAT32 drivers are agnostic to hardware, to SD card, NAND Flash, etc... typically, FAT32 just need to receive blocks of 512 bytes - each block is called a sector.

ATA driver, should read bytes from SD card and send them on that 512 bytes blocks (sectors) to FAT32 driver. This ATA driver must written but we can look for examples, as you suggest on that files on Sparkfun. Also Atmel give example codes.

I think a list of hardware that will be invoked into the project and a start on driver info will be helpful. Examples: voltage regulator, crystals, headphone jacks, resistors, and capacitors wouldn't need code, but joystick, buttons, decoder chip, video, microcontrollers, and SD/MMC sockets would need code.
Starting hardware could use a uniform beginning like voltage regular would be first, then second ..... third....

Looks like you continue to not reading the messages and pages :-) -- all of that information is on TWiki page, also for the firmware, bootloader, etc. However I will update the actual page when I have even more clear ideas.

[casainho]

Yes, I've read the Twiki and its using an evaluation board to start. That's all fine, but to be a DIY there were talks about making or producing a breadboard to have a completed handheld media player. The practical product will only need parts that would be needed, where as the eval kit would have parts that won't be used. Unless this is all based upon everyone using a eval kit?

I think the way to go, is with development board, in this phase of development. I will not spend energies on hardware (thats one advantage of buying the dev. board) but just on learning how firmware should work, how can I put it working.

Later I would like to try to do a simple as possible hardware, for DIY, which will be more like a prototyping.

About "breadboard to have a completed handheld media player" I don't believe on that simple because there are very high speed signals that will fail on breadboard hardware. Plus SDRAM, MCU, etc have very fine pitch measures of pins, almost impossible to make on bread board.

Since now I believe in making a minimalist hardware, I think will be good option to design and after shop online a PCB. On that time of design, we should copy the tested, working hardware of development board.

I'm not sure what your thoughts on ata drivers are respectful on sd cards.

Don't worry - I just need to have a working way for FAT firmware on Rockbox can read sectors (512bytes each time) from SD card.

[casainho]

EDIT on 2008.09.14:
There is a new developer working actively on the project, is the Thomas Lloyd.
Thomas were ill during almost 3 years when he lost about 80% of his sight. He have 25 year old, is an embedded developer, did completed his Computing for Real Time Systems degree in late 2005.

Thomas wrote about his motivation: "Having lost my sight I want to see a reasonably priced unit that takes into account the visually impaired. The experience gain would be valuable in working in the embedded industry again."

Thomas bought the Development board - Olimex SAM9-L9260 -- we are now two developers with the same development hardware.

We both did commit the initial port (in very, very early stage) to SVN on code.google project page.

I am stuck now on C startup code (boot.ld and crt0.S)... reading a lot of examples to try to understand :-)

---
EDIT:
I got a script to quick use Sam-ba, now it loads the code using the USB connection and put it on SDRAM and finally jumps to ti - it's very quick for development, no need to flash it :-)

I also tested the flash LED code from Atmel, which uses a timer to flash the LED :-) -- so now I have code that initialize the ARM and the SDRAM, uses one timer.

My next step is putting Rockbox kernel working and flashing the LED using kernel tick functions.

---
EDIT:
I created a new page explaining and giving the status of a more simpler version: Rockbox Player Little - Prototype.

The idea is to simplify to get Rockbox working on a simple base hardware - no need to have the "special" LCD with x and y colors and size, no need to have the USB High-Speed, etc.

---
Finally I got some advances

Yesterday I managed to build the bootstrap. Before I had to also build the toolchain - I am working on GNU/Linux Ubuntu and with one ultra portable and cheap pc, the Acer Aspire one.

After I use the Sam-Ba Atmel utility to flash the bootstrap on DataFlash memory. Even after I flashed the flash_LED code to test and It did run ok :-)

Next efforts will be to optimize the process of flashing the application to DataFlash memory in a quick way - I must do a script on Sam-Ba and also I must add one switch on hardware to DataFlash chip select line and board reset line.

After I will start working on Rockbox bootloader - which will be the substitute of actual flash_LED code -- nice to being use this MCU from Atmel because there is of drivers to all peripherals and other examples application codes from Atmel - I think will be quick to develop the Rockbox bootloader.

Image at the end of flashing the flash_LED application:

[rtruninger]

Hi

I'm new to this forum and I've only been reading part of this forum, so please excuse me if I cover something that's already been talked about... I am an embedded engineer with 15+ years experience in high speed embedded design including audio encoding/decoding for commercial applications. I would like to build a network media player, I know this is not exactly what you guys are doing, but the hardware could be very similar anyway (I think the only difference is that I need an Ethernet interface). I could help with hardware and low level firmware design and I might even be able to get a few 4 layer bare boards made for free.

Here are a few toughts:

Integrated IDE HD: IDE is on it's way out, I just discovered this when I tried to get a high capacity IDE drive for my old server (ended up getting a new server with SATA, was cheaper). I think in a few years it would be very hard to get IDE drives. Has anyone thought of implementing an SATA interface? I know this might not be a trivial task, but a quick search revealed at least one MCU that has intergrated SATA: OXE810SE (has 367Mhz ARM core and a lot of other gimmicks). An easier option may be to use an USB2.0 hi-speed host IF and stick an USB-HD in it (or memory stick).

CPU selection: I agree that a dual core will be complete overkill. I also think that an ARM9 core is the way to go. I think the main design goal should be to make the hardware as cheap as possible (it's a consumer product). I know the imx27 gives a lot of bangs for bucks, but routing a 400+BGA would at least require a 6 Layer board (most probably 8 layers), which increases price significantly. Also it would be good to know how much grunt we really need. I integrated MP3 decoding on a C6413 DSP from TI, running at 300Mhz, and from memory it took only about 10% CPU (mind you the C6413 can execute up to 8 instructions per cycle). It would be great if we could figure out how many MIPS the most CPU intense decoder (which might be AAC?) would use on an ARM9. Anyone has some data on this?

This would be my requirements on the hardware (please feel free to discuss):

ARM9 CPU fast enough to handle all decoders with ease (probably less than 30% CPU utilization, to make it future proof)
A couple of MB ram and flash
USB hi-speed host or SATA for storage
SD card interface (may be optional)
USB hi-speed device interface
Bluetooth (can be used for headphones and/or remote control (Audio/Video Remote Control Profile (AVRCP)))
LCD Display if
Button if
Audio codec's
I would also need 100Mbit LAN and one extra USB host for an optional WIFI dongle
Battery mangement (which I wouldn't use)


Tricky stuff:

There are not many CPU's with integrated HI-speed USB host, the ones I found that have are all high density BGA.
SATA might be too complicated (hardware and software)
Finding any CPU that can be routed on a 4 layer board (must be LQFP or similar, BGA would most certainly need more layers)
Getting a cheap evaluation board for it, that is supplied with Linux and all drivers (we don't want to reinvent the wheel)

If the CPU does not implement a required peripheral, we can put an external Chip on, drawback additional cost and probably have to write device driver for it from scratch.


Hope my input helps.

[casainho]

I would like to build a network media player, I know this is not exactly what you guys are doing, but the hardware could be very similar anyway (I think the only difference is that I need an Ethernet interface). I could help with hardware and low level firmware design and I might even be able to get a few 4 layer bare boards made for free.

Hello :-)

Why not joining forces? The actual development board we are using have Ethernet :-)

I am not sure, but Rockbox firmware don't have any Ethernet code, so you would have to start coding it.

About the suggestions you gave, I think most of them are important If we were doing a player optimized for production, but we are not on that phase ;-) -- now we just want to make a very simple, minimal hardware, and later we can work on all of that.

For now, our simple hardware setup is:
http://www.rockbox.org/twiki/bin/view/Main/RockboxPlayerLittlePrototype

You can add me to GTalk ou MSN: casainho _gmail.com.

[casainho]

Me and Thomas, we are trying to make a flash_led code working on Rockbox bootloader.

We had working on tools to flash the code and to run it to SDRAM... and we are now investigating about hardware debugger, as JTAG.

Our main problem should be on errors on C startup assembly file and linker script of GCC... it's all new to me, ARM, etc :-)

All our work is being done here: http://code.google.com/p/rockboxplayer/

:-)

[notlistening]

Hi,

Thomas here thought that i would jump in here and get involved in the forum. My partner in crime is ahead of me in the learning process but I need to understand as three eyes are better than two. To get there I am working through an embedded systems with GNU toolchain book to help me get an overall understanding of what has happened already, and in part verify the existing work.

Just of recent I have done the same and taken a mini break from coding. Back after the weekend and should submerge myself yet again till i need to take another breath.

JTAG & LCD will be on order next week.

Tom