FOSDEM is an event I don’t want to miss. This year, I planned well in advance what talks I wanted to see, and it really payed off. With more than 600 talks in just 2 days, and up to 20 concurrent events, it is very naive to just arrive and figure out what you are going to do on the spot. I’ll just give a short impression of the talks I attended.


systemd and Where We Want to Take the Basic Linux Userspace in 2016

By Lennart Poettering. (Link to FOSDEM page)

The talk did not go into the basics of systemd, the new boot process for Linux. Instead it focussed on some tools and services in development. A big part of the talk was about DNSSEC, a DNS feature that allows cryptographic signing of DNS entries. It was well presented, and the speaker did a good job explaining what the caveats are. For example, if you have a private network with your own unregistered domain called private.lan, DNSSEC will complain because the “lan” domain is not signed as a top level domain.

Digital Hardware Design: Why is it still so hard?

By Philipp Wagner. (Link to FOSDEM page)

A general talk that outlined the tools available for designing hardware. Very well presented, it gave an overview of all the free and open source efforts going on trying to make hardware design more accessible for the hobby level. The speaker mentioned the upcoming talk about project Icestorm, which made me decide to change my plans and go watch that instead.

GNU Radio for Exploring Signals

By Tom Rondeau. (Link to FOSDEM page)

I didn’t learn that much from this talk, which pleased me a lot: I’ve been trying to get a hang of gnuradio for years, and I sometimes feel as if I’m not making any progress at all. But a few years ago, I would have found this talk very informative. Now it was a bit boring. Awesome, I’m improving! That said, Tom is a gifted public speaker, and by interweaving some historical background about the battle between AM and FM, he makes it fun for everyone. One thing to remember: using virtual sinks and sources is a good way to unclutter a grc flowgraph.

Digital mixed-language simulators

By Michele Castellana. (Link to FOSDEM page)

Short talk about making a simulator for both Verilog and VHDL (and possibly other hardware languages). The key here is having a good intermediate language.

A Free and Open Source Verilog-to-Bitstream Flow for iCE40 FPGAs

By Clifford Wolf. (Link to FOSDEM page)

This remarkable work is really mindblowing. A completely FOSS toolchain for programming iCE40 FPGA’s is working. The bitstream for the FPGA has been reverse engineered, and the entire process from writing Verilog to programming the FPGA can be done in open source now.

Designing with KiCAD of OSHW 64-bit ARM board

By Tsvetan Usunov. (Link to FOSDEM page)

Tsvetan Usunov is the owner of Olimex. He gave a good and entertaining talk about the use of open source tools in his company, moving away from Eagle and towards KiCAD. Like so many, he praised the open source EDA tool for its development speed and quick bug fixes. He did a good job of pointing out where improvements can be made, based on his experiences as a manufacturer.

He also quickly gave an overview of things to come: Olimex is working on a open hardware laptop, and he told that he will release an iCE40 FPGA devboard: since the reverse engineering of the iCE40 bitstream, the cheap iCEstick devboard has been on backorder. Not only is he a supporter of open source, he also has a good nose for business :-).

KiCad Project Status

By Wayne Stambaugh. (Link to FOSDEM page)

The project lead of the KiCAD team gave a presentation about the work done for KiCAD v4, and the upcoming features for v5. V4 was mostly about the board routing, and for v5 the focus will shift towards the schematics editor. One thing not on the list for the next version is better microwave tools. It was mentioned on the long term wish list, however, so there is hope. And, since it is an open source effort, if someone wants to implement it sooner, it will be included.


Sunday was much simpler than Saturday. I just settled in the Software Defined Radio Devroom, with a short break during the telecom talks about LTE and 4G/5G, during which I went sticker-hunting at the various boots.

The GNU Radio Companion Changelog

By Sebastian Koslowski. (Link to FOSDEM page)

This talk gave a walkthrough of the new features in GNURadio. Bypassing blocks is a feature that I have already grown fond of. And the possibility of embedded python code in flowgraphs is also something that will come in handy.

The GNU Radio Toolkit

By Martin Braun. (Link to FOSDEM page)

A very good introduction to many tools included in GNURadio. Starting with options for installing GNURadio, talking about the guided tutorials (they have been very helpful to me also), gr_modtool, and the community.

Signal Intelligence Challenges

By Felix Wunsch. (Link to FOSDEM page)

Tips and tricks for setting up a SigInt challenge, where participants need to locate and decode RF messages.

Building Self-Optimizing Radios using DEAP

By Andre Puschmann. Link to FOSDEM page

An academic talk about research done on using evolutionary algorithms for optimizing RF links.

Radio Machine Learning with FOSS

By Tim O’Shea. (Link to FOSDEM page)

A short but cool talk about using the same methods that Google used for the recovering images from trained neural networks on radio signals. The neural network generated signals that looked like a bpsk signal.

The rad1o badge

By Tobias Schneider and Stefan `Sec` Zehl. (Link to FOSDEM page)

A nice talk, but it contained a lot of the same material of the one given at the CCC Congress. Not surprising, knowing that the congress was only a month earlier.

Height of the talk was a demo where a power socket switch was turned on and off. It was almost cancelled because the German power socket was incompatible with the Belgian one, but with the help of the audience (someone provided an adapter and another one a USB charger with a LED) it worked anyway.

Using Red Pitaya for radio applications (from LF to HF)

By Pavel Demin. (Link to FOSDEM page)

This talk could have been a lot better, in my opinion. All I got was: he did some things and now Red Pitaya works with some SDR software packages.

SDR Track Panel

By Martin Braun, Tom Rondeau, Sylvain Munaut, Paul Sutton. Link to FOSDEM page)

Discussion about how the different SDR communities can co-operate better. The things that made the most sense were:

  • Making code modular (e.g. Volk is used in other projects now)
  • Meetings like FOSDEM are great
  • Hanging out in each other’s mailing lists and chatrooms

From my perspective, the SDR community is a friendly place to hang around, even if you’re not an expert. I have never seen any drama, and people are generally helpful if you make an effort to understand how things work. They’re not doing bad at all, although looking at how to improve things from time to time is a good idea.

Embedded SDR

By Moritz Fischer. (Link to FOSDEM page)

A rather short talk about cross compiling for embedded systems. His main point: use SDK’s! Thanks – will do!

RFNoC — Evolving SDR toolkits to the FPGA platform

By Martin Braun. (Link to FOSDEM page)

This was a really interesting talk explaining how to use RFNoC. You can define RFNoC blocks in your grc flowgraph, and load these blocks into the FPGA. This means that you can e.g. offload filtering or an FFT transform to the FPGA of your USRP device.

Synchronization in distributed SDR for localization applications

By Johannes Schmitz. (Link to FOSDEM page)

Another interesting topic: using GPS to synchronize clocks of different radios. It showed the accuracies up to a few tens of nanoseconds, and results of an experiment done locating a transmitter.

Wideband measurement strategies: from RADAR to passive wireless sensors

By Jean-Michel Friedt. (Link to FOSDEM page

I always like the talks given by Jean-Michel Friedt, despite him talking extremely fast. This time he talked about Passive sensors illuminated by RADAR. It was very interesting to see how he used a SAW filter to delay a response.

This year it’s a good thing he talked so fast, because he went overtime a few minutes. Fortunately he was the last speaker.

Talks I could not attend

Inevitably there are some talks that clash with others you want to watch. Here are some that I hope will have good video recordings:

Interesting boots

There were a lot of boots at FOSDEM, promoting all kinds of free open source software projects. Here are a few that drew my attention:

  • Diaspora*: I was given a nice demo of the features, and I was pleased to see it work. It’s a great alternative to Facebook, which is pure evil. Of course, getting to convince a billion of users that don’t care about the major privacy concerns is not easy.
  • OwnCloud: Run your own DropBox-like server
  • Kolab: I got a nice demo of an Open Source groupware software package. I don’t need it at the moment, but it’s good to bookmark it.
  • OpenEmbedded: I will take a better look into this for sure.


It’s only possible to attend a few percent of the talks given at FOSDEM, and not all of the subjects are interesting to everybody. But still every talk has its audience, there is a lot of activity in the open source world. For me, the recent developments in free and open FPGA tools are very promising.

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