Hi everyone
I believe this is the right place to announce our project — we are developing coin-sized microcomputer which runs OpenWRT, with onboard Wi-Fi (including PCB antenna) and a lot of GPIOs, friendly for novices as well as emedded electronics professionals. It's open source, including hardware — we will post everything (schematics, PCB, BOM) in editable formats, not only useless PDFs.
Here is the official website: http://www.black-swift.com/, but I'll describe the project below for everyone's convenience.
Short specs:
Dimensions: 25×35×4 mm
Chipset: Atheros AR9331
Memory: 16 MB NOR flash, 64 MB DDR2 SDRAM
Power: 5 V or 3.3 V or 3.6...6 V (onboard voltage regulator)
Power consumption: 60 mA min (200 MHz, Wi-Fi disabled), 120-150 mA typ (400 MHz, Wi-Fi enabled), 300 mA max
Wi-Fi: 802.11 bgn with PCB antenna (NB: there will be no U.fl antenna connector in the final design)
I/O: microUSB (power), microUSB (USB 2.0), 2x10 pin 1.27 mm & 2×15 pin 1.27 mm (GPIO, power, 2×Ethernet, USB 2.0)
Firmware: U-Boot bootloader, OpenWRT Barrier Breaker
Price: $25 basic version, $35 developer edition. Worldwide shipment by Hong Kong Post.
Developer edition has absolutely the same form-factor, but comes with onboard UART-USB adapter and ability to directly reflash NOR memory, so it should be great for people who likes to play with bootloader and/or firmware — unbricking never was easier. Also it comes with 1.27 → 2.54 mm adapter, but later adapter will be sold separetely as well.
Why we did it? We are small company which specializes in professional electronics development, and we were not happy with existing options. For example:
Cheap routers. Not suitable for any kind of professional design, and unconvenient for DIY or prototyping — not enough memory, not enough GPIOs.
EL-M150, Carambola 2, similar boards — surface-mounted, so unfriendly for novices, unconvenient for fast propotyping, ineffective in terms of occupied main PCB space, some of them need external Wi-Fi antenna, others lack onboard voltage sources, etc.
VoCore and other RT5xxx-based boards — slow due to SDR memory (DDR2 is not supported by Ralink's chipset)
Also, the common problem with Chinese hardware: almost impossible to persuade manufacturer to change anything according to our specific needs. We tried and failed, they just don't want to do it (or don't know how to do it, most likely...).
Also, most boards come with more or less stock OpenWRT — which means 100 Hz timer, no preemptive multitasking, no GPIO IRQ support on AR9331, space-efficient userspace software like busybox utilities and dropbear SSH... So finally you have to build your own firmware anyway.
What we tried to achieve here? Mainly, combine the easyness of use for novices and enthusiasts with convenience for professionals in embedded electronics.
2 standard microUSB ports — one for power, another for USB 2.0 interface, so you can connect USB peripherals with regular USB-OTG adapter and power the board with cellphone charger
Onboard voltage regulators — 5 V to 3.3 V and 3.3 V to 2.75 V to power peripherals (although 3.3V-tolerant, it is recommended to use AR9331 GPIOs with 2.75 V)
If you don't need USB power, you may power the board with 3.6...6 V or 3.3 V sharp.
Onboard Wi-Fi antenna, so nothing external needed here
All GPIOs, power, USB, etc. are on 1.27 mm connectors (standard PLLD type), so you can use it in a variety of ways — attach 2.54 mm adapter, solder wires directly to the board, solder it to the mainboard (if you need one) or make it detachable, align to the mainboard or place it at 90 degrees...
E.g. I have two projects with it already — one is a kind of weekend project with everything soldered to eurocard (Christmas tree lights controller, and I'm not, repeat not, joking, I seriously needed that thing), and another is apartment's energy meter with web interface in case small enough to fit on standard DIN rail (even EL-M150 doesn't fit inside it).
And to make something like wireless mp3 player or print server or router (unexpectedly!) you need nothing to solder.
OpenWRT image will have some modifications:
1000 Hz kernel timer & preemptive multitasking enabled by default
GPIO IRQ support on AR9331 (you know, there's a patch available)
Ability to pass variables from userspace back to bootlader (i.e. to change CPU frequency on the next boot)
Normal SSH client instead of dropbear (you can't use Eclipse to remotely debug your software with dropbear)
et cetera
As I said, we will publish everything we did and changed in our wiki — http://www.black-swift.com/wiki?view=categories (some things already published: basic board information, some OpenWRT tips & tricks). OpenWRT images, patches, as well as board schematics and PCB will be published around February, after we get final design and make sure everything is working the way it should.
Also we'll prepare and make available such things as Linux VirtualBox images to develop OpenWRT programs (minimal with SDK and command line, normal with X Window and Eclipse installed and set up), 32-bit OpenWRT SDK, et cetera.
As for now:
We finalized design in January and expect samples in February, so mass production can be started in March-April. It will be third revision, but mostly it's final touches, bells and whistles — so I expect no problems with it.
We have no investors and we are a small company, so we need funds to start mass production — we are going to Kickstarter on January 27 (I'll update the post with the direct link later if you like)
Will be pleased to answer any questions you may have, of course.
