Articles

Previous page  123456  Next page

News 12 years Ago
 
Published by packi on in Logic Analyzer

I’ve got the FPGAs on friday, but had no PLCC sockets to test them out. So I had to wait until the weekend passed by and the package from my local electronics (why do I feel the urge to write drugs, the parts are nearly that expensive) supplier arrived. The FPGAs I’ve received from a customer of ours are Atmel EMP7160S, getting programmed by a JTAG interface and the software from Atmel (Quartus II).

After everything was soldered in place and powered on my powersupply showed a current draw of 0.1 Amps so the circuit seemed to be consuming electrons. That was at 01:30 am.

The next day the FPGAs got programmed but since I had no spare oscillators I had to fetch some (you can place an order by phone or over the internet and collect them after two hours at the electronics suppliers place). After soldering the oscilator wrong twice (notice: the pins on the backside of a part appear to be mirrored ;-) and a coding simple frequency divider in VHDL I called it a day.

Fresh out of the HD an overview of the la:

32 Probes connected to four quad-input latches provide the input. The FPGA decides wheter or not to begin sampling.
If a trigger occurs the FPGA counts the addresses up on the A-Bus and drives the RAM to collect the data.
A PIC is used to communicate with the PC, setting trigger-masks and transfering the data measured.

Since the FPGA is a 84-pin PLCC-package I have about 60 input pins:
- 32 for the D-Bus
- 14 for the A-Bus
- ~9 for communicating
- 1 oscillator (GCLK1)
- 1 variable clock (freq-divider inside the FPGA)

This leaves me with 8 spare pins. Lets me think that I should really get me some thin wirewrap wires, the 0.22 mm^2 wire is just not suited to solder a piece with 84 pins ;-)

More to come…

 
News 13 years Ago
 
Published by packi on in Logic Analyzer

After hours of debugging communications between two PICs running at two different clockrates (well debugging is exaggerated it was more like looking at my no-memory oscope), I’ve decided to build myself a logic analyzer.

It should be capable to record 32k of Data at a sampling rate of ~10 Mhz (I won’t be using anything faster than that *fingers crossed*).. The samlping will be done by discrete logic doing the sampling and triggering. The serial interface will be handled by a PIC.

The basic design is already done and I’m in the process of simulation the logic-part of the circuit in VHDL (using the free version of Simili.

 
Published by packi on in Technology

It seems that Thursday mornings and GDB don’t mix that well:

*** glibc detected *** double free or corruption (out): 0x0000000000530a20 ***

Program received signal SIGABRT, Aborted.
[Switching to Thread 98311 (LWP 3468)]

Well that wouldn’t be that dramatic since we got valgrind to find memoverwrites, right? Wrong:

**3502** new/new[] failed and should throw an exception, but Valgrind
   cannot throw exceptions and so is aborting instead.  Sorry.
==3502==    at 0x11A17958: VALGRIND_PRINTF_BACKTRACE (valgrind.h:321)
==3502==    by 0x11B1A281: operator new(unsigned long) (vg_replace_malloc.c:168)
==3502==    by 0x123DC304: (within /usr/lib/gcc-lib/x86_64-pc-linux-gnu/3.3.4/libstdc++.so.5.0.6)
==3502==    by 0x123DBA92: std::__default_alloc_template<true, 0>::allocate(unsigned long) 
(in /usr/lib/gcc-lib/x86_64-pc-linux-gnu/3.3.4/libstdc++.so.5.0.6)
…

It seems that valgrind didn’t detect any mem overwrites or other anamolies related to these issues. Since I’ve been hunting that “bug” since 4:00am I’ll skip breakfast and go straight to bed.

 
Published by packi on in Technology

It seems that GDB has some issues with optimised glibc builds. This wouldn’t be that drastic, but it makes KDevelop unusable for debugging! And debugging something at 3:00 am with GDB is not very productive ;)
The problem with GDB seems to be that it doesn’t find the right stackframes in the binary and begins to print an endless stream of

…
#7  0x00000000 in ?? ()
#8  0x00000000 in ?? ()
#9  0x00000000 in ?? ()
#10 0x00000000 in ?? ()
#11 0x00000000 in ?? ()
#12 0x00000000 in ?? ()
#13 0x00000000 in ?? ()
#14 0x00000000 in ?? ()
#15 0x00000000 in ?? ()
…

This confuses KDevelop (not surprising at all, since its really an endless stream) and even after killing the debugger it refuses to restart the debugging process.

Now I’m tired and on the way to my bed. Class begins at 10:00am this morning, who needs sleep anyway ;)

 
Published by packi on in Out in the wild

After having lost my cellphone on the “Openair Frauenfeld”, I’m going to visit the LinuxTag in Karlruhe (DE).
I hope I’‘ll be back with loads of information about “Linux on the cellprocessor” or Kolab2, news about grid-computing, usability in the opensource world and lots of usele^H^Hfull gadgets and books.

And hopefully I’ll be able to write in an more adequate climate (lower temperatures than 30° celsius ;)

 
Published by packi on in Technology
WebKit?

The WebKit contains the rendering engine (based on the KHTML-engine) used in Safari, Mail, the Dashboard and many other projects to display HTML content.

 With all the news about Apple moving to the x86-platform I’ve missed the news about the WebKit becoming opensource.

It seems that the requests from the KHTML develpers have been heard, they “complained” that they were not granted access to Apples bugtracking-system even with an NDA now they can even checkout the source from their cvs server. You may have noted the quotes arround “complained” that is, because they never have, it was just that they were tired of people demanding features ported back from the Safari fork, saying that “It’s the same codebase, right?”. Well, it’s the same code base but it diverged rather badly and changes in the Safari-tree are not that trivial to integrate in the KHTML-tree.

Anyway, since I couldn’t resist to see the ACID2 test running on my machine, I had to stop by at opendarwin for instructions on how to build and run Safari with the latest WebKit:

Bootstrap it via CVS (password: “anonymous”):

cvs -d :pserver:anonymous@anoncvs.opensource.apple.com:/cvs/root login
cvs -d :pserver:anonymous@anoncvs.opensource.apple.com:/cvs/root co -P WebKitTools

Run the update-script (fetches the sources) and build it:

WebKitTools/checkout
WebKitTools/Scripts/build-webkit

With the checkin restrictions the project has in place, it’s very likely that the build has succeeded, lets run Safari with the cvs-version of the source!

WebKitTools/Scripts/run-safari

As you can see on the top of this article, the ACID2 enabled build is up and running ;-)

 
Published by packi on in Others

Just wanted to let you know that I am in fact still breathing. I just couldn’t motivate myself to write something, despite the vast of things I could write about:

  • Got my iPod-mini
  • Received a device which I can run M0n0wall on.
  • Apple swapping their PPC chips with Intels x86
  • Sarge being released
  • The hassle with Java on a Debian system

Ah well, my ability to write might actually come back to me. Till then, silence may rule on this page.

 
Published by packi on in Technology

Now this is a cool project! As seen on this slashdot post, its a LED floor, controlled by a laptop running Linux and it even has a xmms-plugin to sync it to the sound. ;)

The resolution is really bad though, I think I’ll stick to my video projector ;)

 
Published by packi on in Others

Since Laura DiDio had nothing to report in the last few months, she’s now complaining about the bashings she got from the “radical elements of the [opensource] community” (source). Well, I won’t disagree with her, that calling at “11 o’clock at night” is an unacceptable response to a news article, but it would make me think about what I’ve written to upset those people (which are really not known to be very communicative).

If all you’re “studies” turn out to be in favour of one big company (read this mail and you know what I mean) and you’ve always reported that this company does no evil to the world, you’re subjectivity might be drifting in one or another direction.

 
Published by packi on in Technology

 After my failed attempt to repair my broken Archos player (scratching a +5V cable over the board isn’t very healthy) and as a “Mac mini” user I felt the urge to get me an iPod.
Fortunately our store at school has iPods at very moderate prices which took another obstacle out of my way, I’ve ordered a silver one. If I had ordered the pink one, I might just have gotten it by now, but apple seems to have a shortage of silver iPods ;-P. You’ll hear again from me, when I get it…

 
Published by packi on in Cockpit

SDCC is an opensource C-compiler for various small processors like the 16F628. After not working on the cockpit project for quit some time I managed to get hold of some spare time and motivation to continue the adventure of hardware “hacking”.

I stopped working on the project after the successful transmition of simple characters over a RS232 interface. It worked quit well for single characters but not for C-strings. It was just gibberish arriving on the hyperterminal (yeah, still programming my chips on windows).

Well last sunday I’ve taken a look at the generated assembler-code from SDCC and surprise, surprise I’ve stumbled over a compiler bug. Seem that the pic14 part of the SDCC has no active maintainer and that bug is not meant to be fixed in the near future. If KDbg hasn’t decided to crash on me after halting the program I may have taken a stab on fixing it. ;-P

 
Published by packi on in Others

I’d do if I ever became an “Evil Overlord”. A nice and compact list of things to remember if you plan to become an “Evil Overlord”. Read it here.

I mean, if you’re ascending to the throne of victory after overwhelming all miserable creatures in this galaxy, you don’t wanna share it with nobody, right? If you proceed according to the list, you won’t be easily thrown of the throne.

 
Published by packi on in Science

The first postulate of Einsteins special relativity theory says, that

“The laws of physics are the same for all observers in all inertial reference frames”

Which basically means, that if you’re in a train, travelling through a train station you can either assume, that you’re moving or not moving at all. A person standing on the train platform can assume, that he’s moving, and the train is standing still, or that his position is static and the train is moving (which would make more sense btw ;).

Well when I was a kid I always pretended the world is moving and the train is not. Einstein says thats a valid assumption but tell that to my parents. And why do I only have a C in physics? ;)

 
Published by packi on in Out in the wild

After a few drinks in a club which I’ve never visited since military service, I found myself lost in the Vibes club (I don’t know if vibes should be written in capital letters bur frankly I don’t care at 1:11 am ;).

Well after a while shaking I bumped into a guy which was standing next to me for about 30 mins, and thought that I’m shaking my hips (along with other bodyparts naturally attached to my body), to get him attracted to me…

Well, moving my body and my mass made him know better (ever been hit by a dumpster? ;)

After a shakehands, we decided to let go of eachother and so our ways separated…

 
Published by packi on in Technology

PBS has an interesting article about four incidents of technical failures or human errors that may have led to a nuclear war, if it wasn’t for the “professional military officers” who decided against a “retaliatory” strike.

Previous page  123456  Next page