Author Archives: slyon

OpenPhoenux Hard- & Software Workshop 2014

Soon this year’s OpenPhoenux Hard- & Software Workshop (OHSW) will take place in Garching (near Munich) at the TUM Campus in Garching. There will be a lot of intetresting topics to discuss and people to meet. Make sure to drop by if you find some time!

The agenda and further details are now available online:

   
 

What’s New in the Linux Network Stack?

Recently, I attented a seminar at university and created a paper named “What’s New in the Linux Network Stack?”. As the content of my paper might be of interest to some people in the community, I decided to publish it here.

Abstract
In this paper, interesting features of the Linux kernel’s network stack are analyzed, which were introduced during the development cycles from Linux v3.7 to Linux v3.16. Special attention is given to the low-latency device polling, introduced in Linux v3.11, the netfilter’s SYNPROXY target, introduced in Linux v3.12 and the new Nftables framework, introduced in Linux v3.13. At the end a trend is presented, which shows the direction in which the Linux network stack is evolving.

What's New in the Linux Network Stack

Download

Feel free to study, improve and build upon my work as desired! Feedback is welcome.

Introducing OpenPhoenux Neo900

openphoenux-logoThe latest device in the OpenPhoenux open hardware familiy is the Neo900, the first true successor to the Nokia N900. The Neo900 is a joint project of the Openmoko veteran Jörg Reisenweber and the creators of the GTA04/Letux2804 open hardware smartphone at Golden Delicious Computers. Furthermore, it is supported by the N900 Maemo5/Fremantle community, the Openmoko community and the OpenPhoenux community, who are working together to get closer to their common goal of providing an open hardware smartphone, which is able to run 100% free and open source software, while being independent of any big hardware manufacturer.

OpenPhoenux Neo900

OpenPhoenux Neo900


With the big ecosystem of free and open Maemo5/Fermantle applications, the hacker friendly N900, which provides an excelent hardware keyboard, the variety of free operating systems of the Openmoko community (SHR, QtMoko, Replicant, …) and the experience in designing and producing open hardware devices of the OpenPhoenux community (e.g. GTA04), they want to bring the best of all worlds together in one single device, the Neo900.

The Neo900 is meant to be an upgraded N900, with a newly designed and more powerfull motherboard, which is based upon the existing and tested OpenPhoenux GTA04 design. Together with the nice housing of the N900 (e.g. slider, hardware keyboard, big screen, …), this is trying to get “the hackers most beloved device”. In the same spirit of the OpenPhoenux community, which created unique cases for their GTA04 devices out of aluminium, wood or 3D printing, there is also an effort to build an aluminium housing for the N900, which might lead to personalized and self-produced cases for the Neo900 in the future and thus the independence of spare parts of N900 smartphones.

n900-cover1 n900-cover2

Due to the fact that the Neo900’s new motherboard is very similar to the GTA04, it is possible to reuse most of the low level software stack like development tools, the Bootloader and the Linux Kernel from the GTA04 project, with just minor modifications applied. This will speed up the software development process of this new open hardware platform a lot!

To fund the development and prototyping of this new open hardware device, which is made in Germany, a crowdfunding campain has been started a few days ago, in order to collect 25.000€ (which is by now already halfway reached!). Depending on the outcome of this fundraising the project might be able to provide better hardware specs than the following minimum keyfeature set:

  • TI DM3730 CPU (OMAP3 ARM Cortex A8) with 1+ GHz
  • 512+ MB RAM, 1+ GB NAND flash, 32+ GB eMMC, Micro-SD-Reader
  • 3.75G module for UMTS/CDMA; 4G (LTE) optional
  • USB 2.0 OTG High Speed
  • GPS, WLAN, Bluetooth
  • Accelerometer, barometric Altimeter, Magnetometer, Gyroscope
  • support of N900 camera module

DSC01773 DSC01774

If you want to see the N900 to live on, help the independet open hardware community to succeed, or are looking for a new, hacker friendly smartphone, you should consider to support the fundraising with a donation. If you donate 100€ or more, your donation will also serve as a rebate for a finished device, once they are ready.

[Update 2013-11-04] The goal of 25.000€ is now reached, less than a week after the fundraiser started! Thanks to everybody who donated and spread the word and thus helped to make that happen. If you want to qualify for the rebate on the finished device, it is still possible to donate.

Let the OpenPhoenux fly on!

Determining Interaction Geometry with Ultrasound Sensors

Just recently I finalized my Bachelor’s Thesis in Computer Science at the Technical University of Munich. The thesis is licensed under the Creative Commons CC-BY-SA 3.0 Unported license and is now available for download.

Abstract
In this thesis I present an ultrasound tracking system, which works infrastructure less and is based on mobile phones. I present the software and hardware, which is needed for this system to work. Then I describe the experiment I conducted to collect data of the system’s performance. Afterwards, this data gets evaluated in a way that it is compared to a high precision reference data set, which was already used to determine interaction geometry. Next, I discuss the system’s and experiment’s limitations and suggest some concrete improvements. Finally I conclude on the possibilities to determine interaction geometry, using the data my ultrasonic tracking system is able to collect and propose some future work in this area.

determining-interaction-geometry-with-ultrasound-sensors

Download

The corresponding software is licensed under the MIT license and is available for download as well: software.tar.bz2

Feel free to study, improve and build upon my work as desired! Feedback is welcome.

OpenPhoenux LinuxTag 2013 Impressions

LinuxTag-Logo
The LinuxTag 2013 is over, and I want to share some brief impressions I got during our stay in Berlin.

The LinuxTag is a nice and well organized FOSS exhibition in Germany, attracting more than 10.000 visitors during 4 days.


We gave a talk about the OpenPhoenux project at the 2nd evening and had about 60 listeners. Some of them got very interested and followed us to the booth afterwards. For everyone who couldn’t participate, the slides are available online: Slides.pdf

We shared a booth with some other “Linux & Embedded” projects, namely: OpenEmbedded, Ethernut, Nut/OS, Oswald/Metawatch. Our Booth was professionally looking and I think we got quite some people interested in the project. Basically we had a constant flow of people at the booth during our 3 days stay and the overall feedback was rather positive!

OpenPhoenux LinuxTag 2013 (1) OpenPhoenux LinuxTag 2013 (2) OpenPhoenux LinuxTag 2013 (3)

We got interviewed by the “GNU funzt!” team, as well. The (german) video is now available on Youtube (OpenPhoenux interview is starting at 5:00):


All in all it was a very nice stay in Berlin. I especially enjoyed meeting and chatting with guys who already owned a GTA04. It looks like the community is growing again!

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