I noticed on the Arduino Yun product page that there is only a partial board schematic, not featuring the Linux/WiFi part of the Arduino Yun, and no editable design file.
This is different from all other Arduino boards until today, for which full schematics and editable design files have been made available.
Is this situation temporary?
What's missing from schematic?
The "MIPS 24K" is the Linux/WiFi chip, aka: "Hornet", AR9331.
The only "Hornet" I know of is not a "chip" but an AR9331-based router from ALFA Network:
http://wiki.openwrt.org/toh/alfa.network/hornet-ub
And the "MIPS 24K" block in the schematic cannot just be the AR9331 SoC alone: the AR9331 chip is a 148-pin, 12 mm x 12 mm dual-row LPCC package, without any built-in SDRAM or Flash memory, requiring a handful of support components.
So, what is exactly under the shield?
Squonk42:
The only "Hornet" I know of is not a "chip" but an AR9331-based router from ALFA Network:
ALFA Network Hornet-UB (based on 8M/32MB version) [Old OpenWrt Wiki]
.....
So, what is exactly under the shield?
The schematic seems fairly complete to me http://arduino.cc/en/uploads/Main/arduino-Yun-schematic.pdf
The RAM for instance is on the last page of the pdf ...
wayoda:
The schematic seems fairly complete to me http://arduino.cc/en/uploads/Main/arduino-Yun-schematic.pdf
The RAM for instance is on the last page of the pdf ...
?!?
There is no RAM of Flash chip in the schematic. On the last page, I only see:
Hi squonk,
I guess the WIFI module with the shield may be similar to WR703n, the one you once did the reverse engineer on it(Very amazing, and so appreciate).
I don't see any special on arduino yun schematic, biggest difference maybe the USB-Hub chip intergrated with the SD card reader.
Thanks for what you did on the RT5350 chip to make openwrt run on it.
gaplee:
I guess the WIFI module with the shield may be similar to WR703n, the one you once did the reverse engineer on it(Very amazing, and so appreciate).
Thanks gaplee!
The WR703N is a commercial product, so there was no other choice... I hope this is not the case with the notoriously Open Hardware Arduino platform!
gaplee:
I don't see any special on arduino yun schematic, biggest difference maybe the USB-Hub chip intergrated with the SD card reader.
Yes, I know the AU6350-MGL chip, very good choice, although you can't get it easily at your corner shop.
gaplee:
Thanks for what you did on the RT5350 chip to make openwrt run on it.
It seems you follow all my moves 
This might help answer some questions....?
Adafruit's "Ask an Engineer" show w/ guest Massimo Banzi. They start talking about Yun, and what's beneath the metal shield at around the 17 minute mark.
1ChicagoDave:
This might help answer some questions....?
Adafruit's "Ask an Engineer" show w/ guest Massimo Banzi. They start talking about Yun, and what's beneath the metal shield at around the 17 minute mark.
Thank you for linking this video!
Always interesting to see Massimo, although it doesn't give much details about the Linux hardware...
What I fear that with the excuse of providing a trendy "Cloud" access, the Arduino Yun is denying its Open Hardware roots 
lock:
I think that if you wanna see the schematic you'd better go to SoC development platform, something like "evalue board", which comes with schematic and such a detailed hw stuff. "Carambola" boards may be interesting.
No, the Carambola doesn't give you the module schematic either, only the uninteresting connectors and passive stuff...
lock:
About WR703N i think it is a toy, poor ram (32Mbyte), poor flash(4Mb), hardcoded uboot's env, no good at all! Also only 2 usable gpio.
You can find some hacks to upgrade the RAM to 64MB and the Flash to 16MB, or buy some already upgraded for you.
The hardcoded environment is really not a big problem, since you don't spend your life in there:)
As for the GPIOs: Linux is far from real-time, and beside blinking a LED with these GPIOs, it is not very useful. The best thing to do is to connect it to a microcontroller to delegate the real-time GPIO control. In this regard, the Arduino is a very good choice IMHO.
There are cheaper alternatives to the WR703N, like the TopLink TOP-AP01:
Only $7.5 in a 8MB/32MB configuration...
lock:
From my point of view the SoC is just an accessory around arduino, something like the wifi shield, so you could see it as "black box", something you can talk through the bridge on the serial port. Also, why do you want to toy with a very complicated piece of hardware ? Soldering and handling the Atheros SoC is not a piece of cake, so any really reason to have much more details about.
The WiFi "black box" is what makes the Yun different from the Leonardo!
Why are you tinkering with an Arduino? You have to wire stuff, solder components, why don't you just program on a PC;)
This is all about learning, building stuff to understand how it is working, knowledge and freedom: you know, all these boring matters... 
Please take a look at my reverse engineering efforts on the TL-WR703N to see my determination 
lock:
p.s.
also you can appreciate how pretty complicated is the firmware on the uboot side, just have a look about the early boot, DDR stuff, TLB, etc, 10000:1 the complexness of arduino bootloader, so you can't really think to handle a so complicated object from scratches, simply silly, not possible for hobby! May be possible for a skilled team, but we are speaking of a job task.
Yes, you are right: even if this is complex, you can actually LOOK INTO IT! This is the whole point: open hardware/software provides you the ability to understand how things work, the limits are yours.
So it is possible indeed... And fun! It just requires a few skilled hobbyists around the Internet. Been there, done that! Actually, pretty rewarding: you learn a lot, and meet some very interesting people!
It is a sad day if we loose this open hardware/software characteristic for the Arduino.
Maybe if you contact Dog Hunter, they can provide more information? (Their website is really lacking...)
1ChicagoDave:
Maybe if you contact Dog Hunter, they can provide more information? (Their website is really lacking...)
Yeah, but given tha little information there, it sounds like a message in a bottle :~
I wish the promises on the Arduino website home page are still true:
The boards can be built by hand or purchased preassembled; the software can be downloaded for free. The hardware reference designs (CAD files) are available under an open-source license, you are free to adapt them to your needs.
I think you can refer dragino ms14 for the wifi part schematic. this board uses same CPU, RAM, FLASH as Arudino Yun and the schematic is available at :Dragino Download Server ./downloads/motherboards/ms14/
Priscilla:
I think you can refer dragino ms14 for the wifi part schematic. this board uses same CPU, RAM, FLASH as Arudino Yun and the schematic is available at :Dragino Download Server ./downloads/motherboards/ms14/
Thanks!
This is exactly what I am expecting to find for the Arduino Yun board.
I am still waiting for an official answer to my OP question, though.
lock:
Priscilla:
I think you can refer dragino ms14The wiki.openwrt has poor informations about, but the most relevant thing is that it has a common jtag interface which i need for the most. Wandering where i can buy one of these unit, it seems interesting!
It looks like they have an online store:
Arduino is NO more opensource from Yun.
From the latest product, Yun, Arduino REFUSES providing EAGLE files (including hardware PCB,CAD files and the placement files) on the official website.
Arduino seems to try to become a company selling hardware all for profit.
The promises NO more extends:
"The boards can be built by hand or purchased preassembled; the software can be downloaded for free. The hardware reference designs (CAD files) are available under an open-source license, you are free to adapt them to your needs."
I arrived at the same conclusion
I don't have any problem with someone making money or selling a name, but I am concerned when you don't respect your promises and treat people like cash providers and pretend to be community-driven.