This is FOSDEM 2018


Last weekend in ULB (University Libre of Bruxelles) took place the biggest Open Source event in Europe – FOSDEM.

With 678 talks, split in 55 devrooms this is something every open source enthusiast waits whole year.

It’s amazing how the organizers make such event possible, between 8 and 10 000 people all around the world come together at one place. If you want to meet some open source project, Linux kernel or Linux distribution maintainer there is great chance to meet him/her there.

FOSDEM usually is made in the weekend Saturday and Sunday, but traditionally starts with Friday evening welcome beer party at Delirium cafe. Do not be fooled by the name nobody go there to drink coffee.


Delirium usually can’t hold all people so the streets around it looks like this:


Every year this event become bigger and bigger. I was always wondering how they manage to keep their WiFi infrastructure in order with so many people attending. This year for the very first time the WiFi was impossible to connect to, so I guess we reach the infrastructure capacity 🙂

In Saturday the talks started, needless to say for me most interesting was the CAD and Open Hardware devroom.

One of the most anticipated talk there was about KiCad 5 new features.

Wayne Stambaugh the project manager started his talk with red T-shirt from Digikey and announced that Digikey made the single most significant donation to KiCad team just few days before the conference. So he said them “thank you” by presenting his talk wearing their red T-shirt.


It was very interesting to hear that Wayne got feedback from popular PCB prototype providers, that about half of PCB projects now they receive for prototyping production are made with KiCad! It’s amazing to see the progress KiCad made for the last 4 years!

I personally like more the T-shirt Wayne was wearing when he closed his talk 😉 KiCad team really like the complex boards we design with their product and this was very kind gesture.


Another interesting talk was Introduction to LibrePCB . This is the first time I hear about this project and it looks itneresting. The author is obviously capable young man and thinkered a lot about how to make component libraries more easy to use, but while I was watching the talk I was wondering (as many others) why the author just do not join KiCad, which is already well established project and leading as features and completeness. We all know that KiCad team is very small and more people joining the project will make much more sense than to re-inventing the hot water, because you do not like some feature in this popular project. Well this is the open source 🙂 and everyone is free to scratch his own itch, but I would love to see Urban Bruhin helping KiCad to become better instead to duplicate the work creating similar product alone.

Jesús Arroyo Torrens presented Icestudio – graphical way to program FPGAs. I would say this is quite entertaining and easy start for beginners with no previous knowledge about electronics.


Juan Gonzalez-Gomez (Obijuan) upgraded this talk with very entertaining presentation about what he did with Icestudio and small funny blocks he created. He is using his daughter as beta tester. I recommend you to watch this talk when the video is available.

Juan and Jesus are part of Spanish community working with FPGAs. You can see more about what they do on this site FPGAwars.

Staf Verhaegen shared his findings about is it possible today to implement ASIC design with open source tools. Very interesting topic, let’s hope the time Makers and small companies will be able to make their own chips with Open source tools is approaching.

My talk was about current TERES laptop status and the experience we got during the development with KiCad. Using FOSS tool like KiCad is great to make OSHW, but if you want to use latest features and the daily builds, they are available only via ppa repository for Ubuntu. This means if you use other distribution you have to build from sources every day. Windows daily builds are not available at all. This confuses many beginners who can’t manage to open our files when they want to study them as they use old builds (official Ubintu repository KiCad version is probably one year old, same for Windows version). My slides are now uploaded at Slideshare.

Other devroom talks I found interesting:

Exploiting modern microarchitectures Meltdown, Spectre, and other hardware attacks 

Programming UEFI for dummies 

Improving Linux Laptop Battery Life

Kodi and Embedded Linux

Linux as an SPI Slave

How to keep your embedded Linux up and running

Drive your NAND within Linux

Image capture on embedded linux systems 

New GPIO interface for linux user space 

It was nice to see three four other talks at FOSDEM by Bulgarian speakers!

Automating Your Lights with Open Source 
Turning On the Lights with Home Assistant and MQTT
Testing Red Hat Enterprise Linux the Microsoft way 

Current meta of video compression and probable futures

Overall FOSDEM is must see event for anyone who is interested in FOSS/OSHW.

Bruxelles is excellent location and offers lot to see, both Wizzair and Ryanair offer low cost flights to this destination and I don’t know where else you can drink beer from half meter glass (not half litter but half meter!) so looking forward to see you next year there!



FOSDEM 2018 the biggest European even for Open Source technologies is approaching!

Screenshot from 2018-01-23 11-08-37

If you have not been to FOSDEM yet you don’t know what are you missing 🙂

Thousands of people who support Open Source meet together for weekend in Universite Libre de Bruxelles, share ideas and talk on interesting topics for the community.

Here is the list of all dev rooms which will be available. Needless to say for us most interesting is the CAD and Open Hardware dev room.

Looking forward to see you there!

TERES I DIY Open Source Hardware Modular Hacker’s Laptop update


TERES-I DIY laptop first shipments started in September last year and we quickly sold the first initial production run. Immediately we start to get valuable feed back. Meantime the spare parts now are online and can be ordered.


Some of the feed back was quite pleasant like this one sent from Martin Krastev:


Този път ви пиша не с въпроси по подръжката, а като потребител на Терес с
няколкоседмичен опит и впечатления ; )

Знам, че по идея Терес-А64 е бил замислен като хакерски ноутбук, но вече
седмици го ползвам като машина за разработка:
1. Освен проектите, по които работя, Терес сам си компилира и
компилаторите, които ползвам — 2-та ГБ памет наистина правят паралелното
компилиране възможно, та дори да е само -j2 или 3 (нещата, които компилирам са сравнително тежки, и по-голяма паралелност вече опира до суоп файла).
Така че голямо благодаря за ъпгрейда на паметта!
2. Въпреки нищожното охлаждане на чипа, Терес успва да държи по-голяма част от времето 1152МХц, което беше много приятна изненада за мен.
3. Клавиатурата се оказа доста ергономична, въпреки че в началото имах
опасения, че ще е малка.
4. Избора на чип от програмна гледна точка също се оказа удачен – някои
прозиводители на А53-базирани чипове орязват архитектурни фийчъри (демек – инструкции), но allwinner не са от тях (за изненада! ; ) Това ми позволява да не се тервожа, че код писан за по-глеми армове може да не тръгне на Терес.
5. Батерията носи добре на натоварване – дълги компилации не угасват по
средата! : ) А и шината за sd карти държи прилична скорост – напъно
сравнима с вътрешния флаш (при прилична карта, разбира се), така че и
проблемът с допълнително дисково пространство за големи проекти е решен.

Ами това е засега! Исках само да ви кажа, че с Терес сте в правилната
посока, тъй както сте създали напълно ползваем работен ноутбук за арм
програмисти, което си е постижение!


Google translate does satisfactory translation so I would not challenge my English translation skills 🙂


There were two issues we couldn’t catch during our tests and went with the first lot to our very impatient customers:

1. LCD backlight, some LCDs cause the backlight circuit inductor L11 to resonance at annoying audible high pitch harmonic frequency caused by the 300Hz PWM.


According to best Murphy’s law practices this problem didn’t show at the first few laptops we build and tested, but when we shipped the first lot some people complained back about it, so we had to find quick solution.
1.1. adding bigger capacitor 100 uF in parallel to C204 was solving completely the issue, but the boards were already produced and shipped to customers;
1.2. adding double adhesive tape which to press the L11 to the plastic cover solved the issue in most of the cases, if this was not enough sealing the L11 with superglue also stopped the noise, which was caused by L11 vibrations, needless to say this was quick dirty and messy fix

Инфорамция как да ъпгрейднем фърмуер на touchpad и бутони:

This issue was completely fixed with adding 100uF to second production lot

2. Touch panel buttons issue. We run out of GPIOs on the keyboard board so ADC was used to scan these two buttons. Again everything was OK when we tested the few laptops we assembled in house, but soon after the shipment people start complaining that sometimes they press left button but laptop register right button and etc, quite annoying!
2.1. the problem was partially fixed with changing the firmware, we posted new keyboard PCB firmware and instructions on GitHub but this not always solved the problem
2.2. the good fix solution was to decrease the resistor values on the PCB and use 1% precision resistors instead of 5% used initially

We do apologize to all customers who had experienced such problem, we guess they are not many, but if someone has still such issue after the firmware upgrade we will send free PCB3 replacement, just please send us your requests to

In the current KITS this issue is solved.


The initial version of the Linux software was not in best shape, the community helped us a lot and we are now on the third release. Special thanks to Alexey Korepanov for reporting lot of issues and fixes! He also made his own Gentoo distribution for TERES-I at GitHub!


As you all know we suck at mechanical engineering and we had to find all plastic parts from Chinese laptop supplier. Some people asked about possible 3D designs of the laptop case but we are not capable to do this. So one of our customers Jeff Moe who obviously has mechanical engineering skills decided to re-design the plastics and make them as models in 3D printed format – he sends me pictures of his progress from time to time which I post here. So 3D makers be patient – there will be soon 3D printed designs and replacement parts for TERES!

EDIT: Jeff just noted me that the design is made by Brent MacKenzie from the Colorado Printing Project.



IMG_20180118_182208 (1)IMG_20180118_183356

It looks the LCD back plastic he designed is even easier to assembly than the original one.




I will post more in my next post about our progress in turning TERES-I DIY Laptop in portable lab with additonal FPGA board which makes from TERES component tester, Logic Analyzer and Digital Storage Oscilloscope with Sigrok.

New Product in stock MOD-WIFI-AR9271 libre drivers and firmware WiFi dongle


AR9721 chipset is the only one on the market with completely open source linux drivers and firmware, this make it WiFi chipset of choice for people who respect their freedom.

We have MOD-WIFI-AR9721-ANT for quite some time and it’s very popular item, but the 200mm antenna make it not quite small. Now we add to our web shop the version without external antenna. It’s with 85 x 25 x 10 mm dimension and have same working distance as the external antenna version.

Open Fest is this weekend! Welcome to the TuxCon-Kitty SMT assembly and programming workshop in Saturday!


Open Fest conference is this weekend 4-5 of November! This is the biggest Bulgarian FOSS event.

Here is the program.

We will run the traditional soldering workshop in Saturday and will solder TuxCon-Kitt boards then learn how to program them. The workshop is free (as in Beer) to participate 😉 i.e. no money will be involved just your enthusiasm and motivation to learn new stuff.

TuxCon 2017 full agenda is published

15241999_541171392758646_9152584434294422876_nJune 3rd
First day will be in Technical University Plovdiv and includes presentations of interesting open source projects and the first Bulgarian Home retro computer Pravetz 8D.
Guest lecturer is Igor Pečovnik who will talk for the popular Armbian GNU/Linux distribution  for Allwinner SoCs.
There will be also two booths for OpenSUSE and Retro computers.

10:30 – 10:50 Opening speech by our hosts from Technical University
11:00 – 11:30 Quality Assurance according to Einstein, Alex Todorov
11:40 – 12:10 Network monitoring by using netflow, Radi Dochev
12:20 – 12:50 dnsdist, Petko Angelov
13:00 – 13:30 Open Source Computer vision for your projects, Marian Marinov
13:30 – 14:00 Lunch
14:00 – 14:50 First Bulgarian HomeComputer – Pravetz 8D, George Dramchev
15:00 – 15:50 Armbian GNU/Linux distribution, Igor Pečovnik
16:00 – 16:30 Tracing python applications, Nikolay Stoizev
16:45 – 17:45 Lightning talks x5 minutes
17:45 – 18:00 Quiz and closure

Traditionally at Saturday evening after the presentation we will continue with non-formal beer event at near by restaurant “Yuzhen Polah 2” at Bulair St 32.

Sunday June 4th we start at 11:00 in Olimex train building at 2 Pravda St.

We will have brief presentation about how to solder and basic knowledge for the electronic components, then we will solder the specially made for TuxCon Kitty badge and learn how to program it with Arduino IDE. 100 badges are ready as kits and will be given away free of charge, but we have limited number of soldering irons, so if you have one bring it to the event 🙂
Members of the local Radio club will install huge antenna at our backyard and have fun like last year.
TuxCon is totally free event made by volunteers in partnership with Technical University in Plovdiv. No need for registration, no entry fees.
Looking forward to see you this weekend in Plovdiv 🙂

TuxCon Open Source Hardware and Software Conference is this weekend in Plovdiv


This weekend is TuxCon, conference about open source hardware and software in Plovdiv, Bulgaria.

In Saturday June 3rd the conference will begin at 10.30 o’clock in Technical University in Plovdiv. There are seven interesting lectures and Lighting talks.

Our special guest this year is Igor Pečovnik who will present Armbian – special Linux distribution for embedded ARM SoCs. Armbian is well known in Allwinner community as it supports almost every board with Allwinner ARM SoCs.

In Sunday, June 4th we will have the traditional Hardware hackathon at Olimex training building.

This year our main street is under heavy reconstruction so prepare for the fun to pass by the border of the near gipsy ghetto to may come to us 🙂


TuxCon Kitty, it’s a badge with buzzer, LEDs and shape of Kitty, which play songs when you touch it nose.


The PCB is programmable by Arduino IDE and you can compose your own melody.

So far we have NyanCat, Mario Bross and Star Wars ready for upload.

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