Dec 11, 2009


thats the stuff im doing at work atm:

POLYMAP3 from POLYMAP on Vimeo.

POLYMAP3 is developed under an open source license (LGPL). POLYMAP3 is based on Eclipse/RAP, OpenLayers, GeoTools, uDig and a lot of other great open source software components.

POLYMAP3 aims to provide a multi-user SDI platform. Supporting the power user with an ad-hoc data workbench, the admin user with configuration workbench and the end users with a simple to use web client and OGC services. UI is the web browser.

Jul 3, 2009

Controlling Mikrokopter with a SpaceMouse on an OpenWrt Router

I improved my SpaceMouse MikroKopter flying setup so that it's now more practical. In the old setup for piloting the MikroKopter with a SpaceMouse ( look here) - I used my notebook for running Riddim. This mainly had 3 drawbacks:
- setup time until i can start flying with this setup was very high
- not reliable enough ( I install software and do experimental stuff on my notebook too often to believe it could be a reliable MultiKopter Controller )
- in the notebook setup piloting was only possible when sitting

In the new setup i use one openwrt router ( asus wl500g premium ) to run the riddim software:
side top

The Datalink to the Mikrokopter is done with ZigBee Pro - which is connected over one MK-USB to the router ( later i can get rid of the MK-USB and use one of the 2 native serial ports in the router to save weigth and power).
The keyswitch to start the mikrokopter and the other switches are connected to an mini gamepad i bought for ~5Eur and took apart to connect wires.

The whole thing is powered by a 2S LiPo ( to ensure the 7805 is not getting to hot).



- very intuitive ( you move the mouse as you want your QuadroKopter to fly )
- one free hand - only one hand needed for flying ( so you have one hand free for operating other functions, for a cigarett, a mobile phone ,a tissue , ... )
- keyswitch to start the Multikopter often lets spectator smile ;-)

- router needs ~1min to boot ( i deactivated some stuff in the init.d allready but i have some more options left i can try like boot_wait_time, removing modules i dont need , ... - i hope i can get it ready in <30s )
- landing ( more touch down than soft at the moment with preasure sensor )
- not really suitable for acrobatic flight

- xm for help on porting to openwrt
- sublab for infrastructure

Mar 26, 2009

6km DUBwise Connection

Holger showed up with a nice improvement of the Range-Extender which gives the possibility to have more than 6km distance between the MK and the Mobile-Phone. The related Forum Post is in german, but perhaps you can see on the Pictures what it its all about ( Hint: big antenna ).

Mar 24, 2009

Quoting Obama

I never thought i would quote an US-President for speaking words of truth so soon but now I can - I really like this Quote:

MR. OBAMA: Well, and part of what happened over the last 15, 20 years is that so much money was made in finance that about 40 percent, I think, of our overall growth, our overall economic growth was in the financial sector. Well, now what we're finding out is a lot of that growth wasn't real. It was paper money, paper profits on the books, but it could be easily wiped out.

And what we need is steady growth; we need young people, instead of -- a smart kid coming out of school, instead of wanting to be an investment banker, we need them to decide they want to be an engineer, they want to be a scientist, they want to be a doctor or a teacher.

And if we're rewarding those kinds of things that actually contribute to making things and making people's lives better, that's going to put our economy on solid footing. We won't have this kind of bubble-and-bust economy that we've gotten so caught up in for the last several years.

* full transcript
* full video

Mar 2, 2009

DUBwise J2ME Installer

With J2ME there is always the trouble with lots of JAR and JAD Files to handle device differences. It's theoretically possible to write a one-fits-all application in J2ME - but only with a lot of drawbacks. One big problem ist the usage of special APIs or profiles. The other big thing is that you have to include different ressources for the same thing to (really) 'work' on the device. Handling these problems on the device leads to very big and slow applications. Keep in mind that some people still pay a lot of $$$ for mobile bandwith and/or have slow devices. Thats why one-fits-all jar's are very rare and DUBwise isn't one of it. But it leads to problems in finding the right jar/jad for a lot of people. And until now this problem was solved by a human (me) by answering questions from users. But I like the idea of letting computers or machines do the monotone work ..-)

The most common solution to this problem out there are device lists - but these lists are never complete and need a lot of maintenance (there are a lot of devices emerging every month). The solution for DUBwise is the "DUBwise Installer" which is a small (<10kb) one-fits-hopefully-all application which assembles information about the device, selects the right jar/jad combination and gives the possibility to install it.
This is an easy way for users, but the coders side had some stepping stones. Now i had to build all possible combinations - and this was more of a problem than it sounds because there are 3456 combinations possible actually:
6 - sound packs
*6 - image packs
*3 - firmware packs
*2 - bluetooth usage
*2 - cldc1.1 or cldc1.0 usage
*2 - jsr179 usage
*2 - FileConnection API usage
*2 - deviceControl usage
=3456 Jars

This is more than one Gigabyte of jar and jad files and took ~6 houres to build on my Core Duo. Reducing the diversity was not an option for me - so i had to work on Filesize ( i didn't want to crash the svn server on the host project) and on compiling speed.
First tests with my standard packers bzip/bzip2 where very disappointing because they did not siginificantly decrease the size - the very minimum i got where ~800MB - and i had a lot less in my mind because i thought that the entropy is not very high and i can compress this content very good (i could explain why verbally but im not able to write it down ..). Then i searched the net a bit to find a better packer - i stumbled over 7zip - but the tests on the site i found only showed a small difference (which is anyway good for the content they tested - but not the jump i searched for). So i gave it a try and the results where amazing - I got a 17MB File with the default settings and compressing/decompressing are rather fast.
The next problem was the build time - until now i had no problem with it because it was less than 10s/build which is ok for building an app - but not ok for building an app 3456-times ..
The most time consuming part were the jumps to ANT where the sources are preprocessed, compiled and stuff. Now i do this only when the code is changed and just bring the right ressources into the jar otherwise.

- jar and jad of the Installer
- Source Code of the Installer

Feb 16, 2009

DUBwise Graph Speedup

The Sensor-Graph in DUBwise ( actual trunk ) is now much faster and the speed is adjustable:

DUBwise Graph speedup from ligi on Vimeo.

Feb 11, 2009

DUBwise ScreenCast Test

I am trying to make a screencast of DUBwise - this is a first result ( sorry for the poor audio ):

DUBwise screencast test from ligi on Vimeo.

Feb 10, 2009

Oktopussy Failsave Test

The most interesting thing about 8 Engines is that some ( up to 4 ) can fail without causing a crash. We made a little video while we tested this "Feature":

Oktopussy Failsave Test from ligi on Vimeo.

Feb 6, 2009

DUBwise RC-Mount

Since i build the DUBwise Range extender - there are some new usecases in which i use dubwise while the MultiKopter is in the air. For that i needed a mount that i have my hands free for flying. This is the mount i build from parts i found in my Hobby-Room ( price of parts <5$ ):





weight of 87g with sun-protection - which is very ok for mounting on the RC:

Feb 5, 2009

OktoPussy first Flights

Very early Flights of the OktoPussy ( the maiden flight got lost in some bad SD-Card ).

OktoPussy first Outdoor flight from ligi on Vimeo.

- Frame ( Design & Construction by seba aka SelectaT )
- FC 1.0 ( green -soldered by Ligi) with Flight-Ctrl_MEGA644_V0_72a_Octo.hex
- 8*Bl-Ctrl 1.2 ( green soldered by Ligi)
- 4* robbe roxxy 2824-34
- 4* esky 002b
- 8x EPP1045
- 1x2100mah 3s Lipo
- lots of wires
- take-off weight ~1200g

OktoPussy from ligi on Vimeo.

Detail Pics:


Feb 4, 2009

DUBwise Range Extender

Finally i had some time for a Project which was in my mind a long time - the DUBwise Range extender.


The Bluetooth Modules in Mobile Phones are very limited in Range ( for reasons of power consumption and size) - which is OK for normal usage of Mobile Phones but was a problem for some use-cases of DUBwise.
The range extender is a little box for the jacket which contains one Zigbee-Pro module ; a Bluetooth Module and power supply. Zigbee and BT are crossed ( rx=>tx ; tx=>rx ).



Now I connect to the BT module in my jacket with the Mobile Phone ( which is <10m in range normaly ) and the (long) distance to the MikroKopter is Made by a ZigBee Pro connection. ( specifyed range ideally by 1mile / 1.6 km )

Beside the range there is one more advantage. I can leave ZigBee on the MK permanently - I dont have to switch between Bluetooth for DUBwise usage and ZigBee for Riddim ...