Rockbox Development > New Ports
Rockbox Player - Project to design and build a Free/Open hardware audio player
casainho:
--- Quote from: Bagder on January 26, 2008, 04:20:57 PM ---
--- Quote from: spark on January 26, 2008, 02:52:45 PM ---there should be a way to turn off LCD backlight if there is no user activity for certain time. (irrespective if we power from mains or battery). This functionality can be added by using a transistor (less than $0.5).
--- End quote ---
This sort of stuff is already done by Rockbox. No need to do anything about it hw-wise really.
--- End quote ---
Software can't control the energy in this hardware: http://www.sparkfun.com/datasheets/LCD/ColorLCD-Carrier-Schematic.pdf
And since we are talking about this, for V2 I would like to have PWM control for this back light of the LCD, so we can make a fade in/out. Also the same for every LED :-)
I know that actual MCU don't have PWM channels, but on V2 we can change to the AT91SAM9RL64, which have PWM and USB full speed.
--- Quote from: Bagder on January 26, 2008, 04:20:57 PM ---
--- Quote from: spark on January 26, 2008, 02:52:45 PM ---
--- Quote ---what if u-boot is erased? how do we recover a virgin board?
--- End quote ---
The at91 chips are easily bootstrapped over serial (or usb I believe) even when nothing at all is in flash.
--- End quote ---
--- End quote ---
Well, I bought the JTAG cable, I think that we can program all with JTAG. I bought mine in SparkFun at the same time I bought the LCD carrier board. http://www.sparkfun.com/commerce/product_info.php?products_id=275
There is other alternative, the USBprog :-) - http://www.embedded-projects.net/index.php?page_id=165
I believe that It can be also bootstraped by JTAG :-) - I don't have any experience with JTAG or 32 bits, ARM, MCUs. I just read a lot about them :-)
Text taken from datasheet:
AT91SAM9260 Boot Program
The Boot Program integrates different programs permitting download and/or upload into the dif-
ferent memories of the product.
First, it initializes the Debug Unit serial port (DBGU) and the USB Device Port.
Then the DataFlash Boot program is executed. It looks for a sequence of eight valid ARM excep-
tion vectors in a DataFlash connected to the SPI. All these vectors must be B-branch or LDR
load register instructions except for the sixth vector. This vector is used to store the size of the
image to download.
If a valid sequence is found, code is downloaded into the internal SRAM. This is followed by a
remap and a jump to the first address of the SRAM.
If no valid ARM vector sequence is found, the DataFlash Boot program is executed on the sec-
ond chip select.
If no valid ARM vector sequence is found, NAND Flash Boot program is then executed.
The NAND Flash Boot program looks for a sequence of eight valid ARM exception vectors. If
such a sequence is found, code is downloaded into the internal SRAM. This is followed by a
remap and a jump to the first address of the SRAM.
If no valid ARM vector sequence is found, SAM-BA Boot is then executed. It waits for transac-
tions either on the USB device, or on the DBGU serial port.
Bagder:
--- Quote ---Software can't control the energy in this hardware
--- End quote ---
Are you saying that the software can't switch the backlight on/off ?
casainho:
--- Quote from: Bagder on January 26, 2008, 05:07:49 PM ---
--- Quote ---Software can't control the energy in this hardware
--- End quote ---
Are you saying that the software can't switch the backlight on/off ?
--- End quote ---
Yes, I was. Sorry, I should be objective. Software can't switch backlight on/off because this hardware don't do that on/off: http://www.sparkfun.com/datasheets/LCD/ColorLCD-Carrier-Schematic.pdf
spark:
Thats why i said we should send 3.3V power to the LCD through a MOSFET switch with its gate connected to the I/O line of the uC. With this way we can swith on/off the LCD through software.
since both backlight and LCD logic are powered off, we will have to re-initialize the LCD on each power cycle.
V1 and V2
we cannot call a dev board + expansion board as a V1. that is just an eval platform.
A V1 needs to have its own board and we should be developing it, here in the wiki and forum.
if Olimex (or other vendor) is interested in developing the board, we should invite their engineers to join the forum and give their inputs. we do not want them to develop the board in their closed rooms. that looses the essence of open source development.
casainho:
--- Quote from: spark on January 27, 2008, 12:54:08 AM ---V1 and V2
we cannot call a dev board + expansion board as a V1. that is just an eval platform.
--- End quote ---
Okok, someone already told that :-) - I feel the need to document all hardware + software of the dev board + expansion board and for that I will need to have a TWiki page, and for that I need to give a version to that, It can be V0.1, maybe, no? - remember that MCU will be the same to others future versions. - what can be the version name for this first prototype - including hardware + software?
--- Quote from: spark on January 27, 2008, 12:54:08 AM ---A V1 needs to have its own board and we should be developing it, here in the wiki and forum.
--- End quote ---
Right, but there is a good option in the table now, we don't need to go for all the work, time and money consuming, we have a company that can do that for us, a company that have people with experience in that, from design, to choose good, available in market, components, and assembly.
The company here I work, design hardware is strong connected with shop section of the company and assembly section, because It can't be totally separated processes.
--- Quote from: spark on January 27, 2008, 12:54:08 AM ---if Olimex (or other vendor) is interested in developing the board, we should invite their engineers to join the forum and give their inputs. we do not want them to develop the board in their closed rooms. that looses the essence of open source development.
--- End quote ---
I already invited for that, but they have no time for this, they are busy with theirs "normal" work! Also I remember Bagder told: don't put your hopes to a company doing this settle for a hw design and use that build-your-own style prove that the design works and that there's working software should put yourself in a better position when trying to convince companies...
So I feel very luck in have this 2 positive answers from the only 2 companies that I contacted!! I am sure they believe in the project, not only, because Rockbox already works in many hardwares, have a lot of good features and there are a lot of happy people!! Thanks to developers :)
About Olimex or other company develop board in close, that is no problem to me, If they give full schematics and use ICs approved by us. If we look at their dev boards, we know all, we have schematics and the place of components in the board. If company draw the board for them assembly it, let It stay with them if they do not want release it public. We having the schematics, we can then draw the board using our Free Software programs. If Another company wants to make also the board, they can design for them selfs or use our design in KiCad.
About Olimex, even If we don't have their engineers here, we have schematics of their boards, we can reuse their schematics knowing that they have knowledge about that and it works...
When they suggested "AT91SAM9260 + LCD NOKIA 6610 + 8MB flash + 8/16MB SDRAM + nRF24L01 wireless chip + audio CODEC + Li-ion battery + charger + miniUSB + buttons", I didn't mention wireless nor battery, they just suggested that, so I assume that after we show prototype working on that Olimex dev board, we can say what we need and they can tailor a schematic for us and after we can approve it or say the necessary changes.
They have a board with an TFT LCD 3.5" 320x240 pixels with TOUCH SCREEN, they have boards with Ethernet and wireless... what can we need more? :-)
Spark, thinking like this, I don't need to have in the dev and external boards, hardware to switch on/off the back light of the LCD or others things, that can be defined for the next board. And we can just say that in text and engineers from Olimex will draw that, just If we will not be satisfied with result, we can than design as we want/need.
And we should control the quality of the hardware, to have a good sound quality as possible. Thats an advantage that this player can have, I remember to read on wikipedia page about the Ipod, that are models that have bad sound quality, because of cheap hardware. My daily work is also, at the end of the prototype, find smaller values of capacitors, inductors, etc, to reduce the price of the system!
This are my ideas.
EDIT: We can start defining, writing, what hardware we want in V1 (can be a audio player and recorder)! For example, I tough in one version for a flash player and another for a HD player, but now I think It can be possible have pcb with an SD card connector for having a flash player and a connector for an HD. People that want use an HD, just connect it on the board. Looks like there are a lot of people here at RB that likes to have a portable player with 250GB.
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