Playing with Arch

Good evening 🙂

This morning, I have installed ArchLinux as a VirtualBox and the PCB VirtualBox on my portable hard drive. Thus, I can switch between my laptop and my desktop computer.
During, the ArchLinux installation, I have got one problem. I firstly forgot to format the boot partition for EFI. When I arrived at the end of the installation and I had to install gummiboot, I was blocked since the boot partition wasn’t mountable. I formatted the partition and I mounted it at /mnt/boot, a new problem appeared. The mounted partition erased the data written during the pacman base installation. I discovered the name of one of the missing file : vmlinuz-linux. In order to get back only the missing files and without reinstalling the whole system, I was looking for the only package to re-install. I succeeded with this program : pkgfile. Finally, I only re-installed the package core/linux and I was able to try Arch!

This afternoon, with my colleague in HeRos, we were looking for the components. We have almost found everything.
We will use the alimentation of the pololu in order to supply our PCB. I had some difficulties to find a laser. My constraint was to find a class 1 laser, because of the danger of laser. On the website given by Alexis, I found nothing under class II. I had to go on other website and I found something cheaper on Conrad website.



today we begin to define some PSSC for our balls project migB, and begin to think about components we need. According to our teachers, it is very hard to analyse a motion system with an IMU, that’s why i did research about it. It seems that orientation sensing is very easy, while getting velocity and position is much harder. Indeed getting velocity and position requires at least one mathematical integration. So if you get an error on acceleration, even little, and you always get a little error at best, this integration which increases the error. Therefore it is impossible to be very accurate over time. But how much do you want to be accurate ? This is very difficult to foresee which algorithm you will need to get what you want with your IMU, as soon as your project is such specific. Until now the only good one i found is the Kalman Filter, but i’m afraid that our errors could be negligible and thus Kalman Filter would become a big algorithm for nothing.

Also i installed Archlinux on the last computer available to us.

Chapter One: The computer who boots

Voldemort: Don’t you turn your back on me, Harry Potter! I want you to look at me when I kill you! I want to see the light leave your eyes! 
Harry: Have it your way!
Voldemort, Harry: Avada Kedavarose!/Expelliarose!
Harry Potter and The Gobelet of Fire (2005)

Everyone knows how powerfull an Expelliarose spell can be… I hope my team will be powerfull and relentless too!
I hope we’re going to create a good game… and that we’ll be able to play it in two months!

Today, I finished the installation of Arch on my laptop (I used to have problems with internet connection) and I installed Arch on one our PC at school… and as 16nek, I had problems with UEFI! I still have some little problems with the Xserver but… I’ll manage to fix it.

Today was also the first Sam’s lesson about real time OS and with my fresh-usable laptop, I can finally began the work on the STM32… or maybe just installing the tools that I need.

Our group took a little time to talk about our problems (specially the detection and recognition of an opponent – see lelio’s post), to divides the task and to look up at some specific composant.

And since I haven’t post in a long date, here are some old news:

  • I’ve finished and send my tutorial about LEDs… I enjoyed the part about colorimetry because I have a few notions in photography and so a different point of view on the thing
  • I worked a little my signal integrity lesson but it’s still very very very hard
  • I installed Arch on my laptop (though I finished my networkconfiguration today…)
  • I realised that it was hard to write in english (so, excuse me for bad english!)


See you !

Balls coming soon


in the last two days we chose a name for you projet, MIGB, which means Many Interactive Games in a Ball, and begin a wiki to descript it : what do we want that the balls do exactly ? We still search new idea.

Moreover i achieve to install archlinux on my computer, with the help of other members of rose2015 (and web of course). I decide to do not use any other OS on my computer, so that it prevents me from escaping difficulties.



Today we (Julien, Damien, Marc, Dimitri and me) chose a name for our Teddy Bear project ! We are proud to present you “Kudly”, the new connected Teddy Bear. After an installation of ArchLinux on our computer, we are carrying on our meeting of this morning, and talking about the PSSC and the PCB. I’ll give you some news later.