29GBP / 34EUR / 43USD embedded linux, 320Mhz, wifi-N

[limor]

UPDATE Dec 2011:

- Developer Notes for the MiniEMBWiFi board are now available for donwload here http://robosavvy.com/RoboSavvyPages/Omn ... -Mar11.pdf

These include information about the Pinout of the Serial port connector and How to Install a new Firmware on the board.

- Pre Compiled Firmware based on OpenWRT (including Luci): http://robosavvy.com/RoboSavvyPages/Omn ... pgrade.bin

This firmware has been compiled by RoboSavvy and includes a bugfix for on the I2C bus. Webcams (UVC drivers) should now work correctly with this firmware.


Future updates and newer firmware revisions will be uploaded to http://robosavvy.com/RoboSavvyPages/Omnima/



MiniEMBWifi ships from UK and somehow its site has a hobbyist kind of look similar to Bifferboard. It comes with more CPU horse power and includes wifi-N. Few threads have been posted here about bifferboard and what can be done with such a tiny inexpensive board.

Hardware:

- MIPS 24KEc 320MHz CPU
- 8 MB NOR Flash
- 32 MB SDRAM
- 1x WLAN 802.11n
- 1x WAN/LAN Port 10/100M UTP
- 1x USB 2.0 OTG/OHCI/EHCI
- 1x UART serial port
- Antenna 3dBi Dipole detachable antenna x 1
- Output Power 11n: 15±1dBm, 11g: 15±1dBm, 11b: 18±1dBm
- Power Adapter 5VDC, 2.5A Switching Power Adaptor
- Dimension: 67(W) x 50(D) mm x 15(H)
- Temperature Operating: 0~50oC, Storage: -20~60oC
- Humidity Operating: 10~90% (Non-Condensing)
- Storage: Max.95% (NonCondensing)
- Certification FCC, CE

Software

- Preinstalled Linux 2.6 OpenWrt / LuCi web configuration interface
- opkg dynamic package manager allows pre-compiled OpenWrt packages to be installed without having to recompile the firmware
- Preconfigured ssh access to the unit
- DHCP client enabled by default
- Automatic location of the unit's IP address

[nunogato]

Hi,

Just started to work with this board, compiling new kernel, etc and I'm having some problems

From the fonosfera wiki it seems very easy but when you select some modules it just does not compile.

after some attempts (and with a i7 to compile it faster) I realized that these are the steps to compile the kernel (i'm using ubuntu 9.04):

install the necessary packages:
sudo apt-get install subversion g++ libdigest-crc-perl ncurses-dev zlib1g-dev gawk bison flex autoconf intltool-debian intltool

Checkout the source from the fonosfrera svn:

svn co http://svn.fonosfera.org/fon-ng/trunk/

install fon feeds:

cd trunk
./install.sh
cd openwrt


Change the settings in menuconfig: (I've selected in the target system "La Fonera2.0n") you can select the packages you want here
make menuconfig

Run the make with verbose mode (if you like it):
make V=99

It will download some sources and there are one file with one error, one config file in itallian needs a " in the end of the line 323 file "trunk/build_dir/mipsel/luci-0.9+svn/i18n/italian/luasrc/i18n/default.it.lua"

After change this run again:
make V=99

Then you can change the settings in kernel_menuconfig and "Machine Selection -> DRAM Size" to 32MB
make kernel_menuconfig

Run again:
make V=99

if everything is ok image will be in

trunk/openwrt/bin/openwrt-fonera2n-squashfs.img


After compiling it successfully without any change in the settings (only the described above) I tried to remove and add some modules and here comes the trouble.

With my tries I always had to do this:

make menuconfig (make the changes you want)
make kernwl_menuconfig (even if you don't need to do any changes)
make V=99

If you are lucky it will compile, with me it compiled depending on the settings I've selected in menuconfig, sometimes it just died in the middle saying that could not find some module

That's all for now. Next Monday I post here more news.

If anyone has some experience in compiling kernels comments are appreciated

Regards
Nuno Gato

[limor]

the default image is configured as a wifi router - internet is on the LAN side and clients on the WIFI side. This is not good for robotics applications. So after desperate searches on the web finally Omnima came up with a solution which uses an alternative wifi software, not the fon/wrt software.

we managed to do the following:

1) compile the image without firewall, fonera and luci which take space and are not needed for robot applications

2) replace the wifi kernel modules from wrt/fon to ralink secret ones as described here http://www.omnima.co.uk/forums/index.php?showtopic=190

3) got the wifi to work but not with DHCP but with static ip address

4) managed to get mjpg_streamer to run and stream a cheap webcam at decent quality (5fps at 640x480 or 10fps at half).

Code: Select all

mjpg_streamer -i "input_uvc.so -d /dev/video0 -y --resolution 320x240 --fps 9 --quality 50" -o "output_http.so -w /webcam_www/"

you then connect via 192.168.1.2:8080 on the browser and see the compressed video stream. (btw: without the -y or -yuv you get all kinds of errors and it took a while to find the solution on the web)

next steps: getting opencv to cross-compile for the Ralink cpu and then for some blob tracking. then trying to use it with a powered usb hub. then trying to fit this thing inside a robobuilder and seeing how a lipo battery can be fit too, voltage regulation, and some way to link the blob tracking with the robobuilder gaits via serial port with ftdi or the one on board...

[siempre.aprendiendo]

34€?!

Wow, how could it be so cheap???

It seems that the SBC-as-robot-brain family continues growing

[limor]

This is the only way forward for many reasons

- The fun in this hobby is about innovation and cutting edge technology.
- PIC and Atmega have had their run as robot brains. They are great at doing real-time stuff and digesting loads of sensor input but if you take the DARwIn software framework as a glimpse of where the future is heading, then the small microprocessors have a minor role in that future. DARwIn runs on linux with 10x the megaherz of an atmega.
- WRT Linux distribution runs on wifi routers that sell in 100k units and therefore are have the economy of scale. ie: cheap compared to a Gumstix on per-mhz basis.
- WRT Linux routers are used for a variety of after-market wide range of DIY "applications" including surveillance, internet radio, sensor network.. Why not robotics?
- Price per CPU cycle and memory compared to Atmega or the small Arms is 10x to 100x better on the WRT devices.

[nunogato]

2) replace the wifi kernel modules from wrt/fon to ralink secret ones as described here http://www.omnima.co.uk/forums/index.php?showtopic=190

Actually we didn't replaced the kernel module, we just compiled the base version without fonera and luci stuff and the firewall.

to get the wifi working just need to do this:

Code: Select all

uci set network.lan.proto=dhcp
uci set network.lan.netmask=255.255.255.0
uci set network.lan.ipaddr=192.168.1.125

/etc/init.d/network stop
brctl addif br-lan ra0
brctl delif br-lan eth0.1
/etc/init.d/network start

iwpriv ra0 set NetworkType=Infra
iwpriv ra0 set AuthMode=WPA2PSK
iwpriv ra0 set EncrypType=AES
iwpriv ra0 set SSID="yourSSID"
iwpriv ra0 set WPAPSK=XXXXXXXXXXXX
iwpriv ra0 set SSID="yourSSID"

ifconfig ra0 192.168.1.125 netmask 255.255.255.0 up
route add default gw 192.168.1.254

echo 'nameserver 8.8.8.8' > /etc/resolv.conf

with this we connect to our local LAN and internet is working

[siempre.aprendiendo]

This is the only way forward for many reasons

These are very good news. Programming ATMega microcontrollers is funny, but it's more difficult (at least without JTAG) that programming "standard PCs" or similar SBCs.

- The fun in this hobby is about innovation and cutting edge technology.

Another great fun is that it implies very different knowledges: electronics, mechanical, software. Even only in the software area it includes very different specialities (machine learning, real-time, control theory,...)

- PIC and Atmega have had their run as robot brains. They are great at doing real-time stuff and digesting loads of sensor input but if you take the DARwIn software framework as a glimpse of where the future is heading, then the small microprocessors have a minor role in that future. DARwIn runs on linux with 10x the megaherz of an atmega.

I've been reading Darwin information and source code. It's very interesting, but too much expensive. Nao is cheaper, at least with the developer program (although still expensive). I hope Aldebaran continues "opening" it and Darwin going cheaper

- WRT Linux distribution runs on wifi routers that sell in 100k units and therefore are have the economy of scale. ie: cheap compared to a Gumstix on per-mhz basis.
- WRT Linux routers are used for a variety of after-market wide range of DIY "applications" including surveillance, internet radio, sensor network.. Why not robotics?
- Price per CPU cycle and memory compared to Atmega or the small Arms is 10x to 100x better on the WRT devices.

Aha, thanks, Limor, now it seems more logical

[PedroR]

Hi all

As you probably know we've hosted a LIVE streaming event for two 2 days using this board. (Coverage of the event here http://robosavvy.com/forum/viewtopic.php?p=31429#31429 )

We've compiled the kernel following the steps we already posted above and installed the MJPEG streamer package.

Once you get the kernel compiled, you have access to a whole repository of software, ready to install using opkg.

To prepare for the event, using opkg we've installed:
- ssh server
- sftp server
- pureftpd
- The mjpeg streamer

So no custom compilation, toolchain or any hack was needed. We were thrilled to learn about this as this makes the board really easy to use, almost like any other Linux distro.


As for the streaming event, we've used a Microsoft LifeCam HD which was immediatelly recognized by the board.
The kernel was compiled with Debug messages being sent to the console so whenever there are important system changes you get a message which helps during this debug stage.

We managed to get the stream going at 424x240 at 5fps. CPU usage was about 90% during the whole process with the m-jpeg streamer taking the whole 90%.

The mjpeg streamer also includes an embedded webserver so the board was serving a website where you could watch the Live stream in different ways (still pictures, JAVA applet, JavaScript) and we were also uploading the stream to Veetle.


The UPs of our experience were:
- The image/stream was actualy very decent (you don't get the HD details) but both website access and image fluidity were at an excellent level (I couldn't even tell we were doing only 5fps)

- Setting up the whole system was a breeze with opkg giving us access to a wide range of software packages.
For example, we needed to modify a few webpages and we did so over SFTP .

- Reponsiveness of the system was very good. Even though the mjpeg process was taking 90% of the CPU, the remaining CPU time was enough to serve the webpages from the board.

- Console Access to the board is very easy with the built in COMM port and the supplied USB to TTL serial cable.


The DOWNs:
- From time to time the the mjpeg streamer aborted with a segmentation fault. We were unable to track down the reason but it seemed to be very random.

Despite the SIGSEGVs from the mjpeg streamer, the board never crashed nor did we experience any kernel panic or loss of functionality. Whenever the mjpeg died, we went in through SSH and restarted it.

I don't how the experience was for people outside our office as we have limited upload bandwith but in here (and watching through veetle) we are very happy to say you couldn't tell this was being done with such a little, low cost board.


Our next step is to connect the COMM port to a Robot and interface with it along with implementing Vision Recognition.
The COMM port is at 3.3V so you can connect it to:

** Robobuilder Bluetooth socket (and use the RBC protocol the control the WHOLE robot, including querying sensors, playing motions, and doing servo bys ervo control)

** Bioloid Zigbee port. The Zigbee ports on Bioloid are also 3.3V. Using the standard firmware you can only emulate the Remocon protocol (this is the same as saying you can send commands to drive the robot around but can't read back information).

The detail we're working on right now is understanding how to share the COMM port between the console and the Robot application (and also how to deal with the kernel Degud messages that pop up).

We'll post more news as we progress.

Regards
Pedro.

[nunogato]

Omnima has made available their latest work/version of the OpenWRT firmware for the MiniEMBWiFi board.
It can be downloaded here -> Direct Link (please you need the Omnima Serial Cable or a USB to TTL (3.3V) board to enter the bootloader through the Serial Console)

Once you flash the board with this firmware you need to connect to it over Ethernet (with an Ethernet cable) and enable DHCP on your computer. By default the distribution will give your computer an IP address and you access the Luci GUI to configure the WiFi. The WiFi can be configured to work as a client of an existing WiFi network or as a host (serving clients). This is done via the Luci web interface.

In addition, the Luci web interface also offers access to the Package manager. You can view available software, install and update software packages using the Luci web interface as well.

[marco]

Hi,

just reporting an unexpected experiment I made: I mistakenly connected a 12V DC adapter to the Omnima MiniEMBWiFi board board instead of the standard 5V adapter. Fortunately the board handled the extra volts quite well (i.e. it worked) except for the USB bus. It seems that the board doesn't do any kind of regulation on the USB power lines and simply passes whatever it receives as input. The result was a fried USB camera that was connected to the board, nut the board itself survived pretty well.

So if you want to be safe, don't power it with anything besides 5V.

Cheers,
Marco

[bmc]

Hi,

Has anyone tried/does anyone know whether it would be possible to interface a GPS module to the UART pins on this board?

Any pointers to related information would be really appreciated.

Thanks.

[limor]

haven't tried but gpsd package is available for wrt distribution and for example this gps module is 3.3V compatible with the UART on the omnima. You will need to disable the console log messages thrown at the serial port. See how to do it in this thread.

Please report your findings

Hi,

Has anyone tried/does anyone know whether it would be possible to interface a GPS module to the UART pins on this board?

Any pointers to related information would be really appreciated.

Thanks.

[bmc]

Hi limor,

Thanks for the advice, that is exactly the solution I was thinking of. Unfortunately that module appears to be discontinued with no replacement.

These appear to be some alternatives though from what I can tell:

http://www.coolcomponents.co.uk/catalog ... cts_id=518

http://www.embeddedadventures.com/shopdetails/pid/71

http://www.roundsolutions.com/shop/prod ... apala.html

I'll order the Sparkfun board (do you agree this is suitable? sorry I don't know anything about UART) and report back how I get on.

Cheers.

[nunogato]

Hi limor,

Thanks for the advice, that is exactly the solution I was thinking of. Unfortunately that module appears to be discontinued with no replacement.

We still have one last unit of the GPS Micro mini and with a special price. check it http://robosavvy.com/store/product_info ... cts_id/535

[PedroR]

Hi all

We're happy to announce we've compiled a number of resources for the Omnima board that should consilidate all the information about operating the board:

- Developer Notes for the MiniEMBWiFi board are now available for donwload here http://robosavvy.com/RoboSavvyPages/Omn ... -Mar11.pdf

These include very useful information such as the Pinout of the Serial port connector and How to Install a new Firmware on the board.

- Pre Compiled Firmware based on OpenWRT (including Luci): http://robosavvy.com/RoboSavvyPages/Omn ... pgrade.bin

This firmware has been compiled by RoboSavvy and includes a bugfix for on the I2C bus. Webcams (UVC drivers) should now work correctly with this firmware.

Future updates and newer firmware revisions will be uploaded to http://robosavvy.com/RoboSavvyPages/Omnima/


If you'd like to use the latest version of OpenWRT and compile your own Firmware package, Updated Instructions for Compiling the Kernel/Firmware for the MiniEMBWiFi can be found here http://www.omnima.co.uk/forums/index.ph ... &#entry641

Merry Christmas to all!

Regards
Pedro