February 2011
1 post
introducing rawk
tl;dr rage against web frameworks
It’s no secret that my skills as far as web development is concerned are pretty much nonexistent, but at the same time, having a personal website or project websites is pretty useful. Previously, I had a hand-coded site which consequently had only two or three pages in it. I thought there should be a better way. I didn’t want to use a full-on web...
September 2010
3 posts
switching keyboard maps in X
Needed to figure out how to type some Swedish letters:
setxkbmap se
setxkbmap en_US
3 tags
New Project - Beagle-based Wearable
I recently started a project to build a wearable beagleboard based system.
I’m trying to dig up my ARM JTAG system to rejuvinate the mp3 player project, and I have some crazy ideas for an AVR arduino-like system.
May 2010
1 post
post dual-boot upgrade
I dual boot Windows XP and OpenBSD (I used alpeh0’s excellent tutorial at http://www.aleph0.com/computing/openbsd/dualboot/ ). I recently upgraded to 4.7/i386 and realized my clock was now out of sync.
Just need to redo the following steps in the tutorial:
“Then, as root, enter config -e -f /bsd. At the prompt, enter timezone 480, substituting whatever number is appropriate. If...
April 2010
1 post
pf.conf notes
I just returned to pf after a year (maybe longer) away from it. I had fun returning to pf and getting my soekris running as a router / VPN / blah blah blah. This post is mostly stuff I’ll need to remember in the future if / when I get stuck doing other stuff.
The new scrub rule format is like such:
match in all scrub (options)
Need to remember this.
And as for the NAT rules,...
March 2010
1 post
Unplugged for a bit...
Dropping offline for about a month for some work-related fun.
February 2010
21 posts
Roboduino Revision 1.01
Had to make some large revisions to the roboduino board: namely, I had miscounted the pins on the programming header and was using only five pins instead of six and I was using one decoupling cap for both AVCC and VCC, among other errors. The design has been refined. New schematics are available, and soon I will sleep (at 0715 in the morning) so maybe I can design things without such glaring...
3 tags
Roboduino
In designing this robot, I’ve realized that every Arduino board I’ve seen so far has been lacking one thing that I wanted to see: the ability to mount it to a platform using screw holes. I began designing my own, using the Arduino 2009 reference design as a starting point. However, I started designing it at 0430 and finished right around 0515. I’ve posted a PDF of the schematic...
mega324 Robot Control Board
mega324-based control board for the robot; once I start adding more stuff to the bot (i.e. RF links, GPS, possibly fluxgate compass and / or IMU, manipulators, camera, etc…) I’ll need more horsepower. An ARM7-based board (I’m partial to the LPC21XX series) is in the works, possibly an MSP430-based one as well. Initially I’ll probably be used a Modern Device RBBB board...
Robot Power Board
This is the power board that’s designed to take power from a 7.4V two-cell LiPo battery and provide 5V out. It features a DC jack and MAX1555 to charge the batteries, there are no plans for a USB connection for power. I’m planning on using two 2A LiPo batteries from Sparkfun connected in serial using the following PCB:
It could be done by just hooking bare wires up to each...
Drivetrain Test
I have a rough draft of the Drivetrain library for the Arduino coded; a video showing the code in action is available on vimeo at http://vimeo.com/9544359.
The sketch looks like this:
#include <Motor.h>
#include <DiffDrive.h>
#include <Ping.h>
#define PINGPIN 3
#define STOPDIST 10
int distance;
// set up ultrasonic ranging sensor
Ping...
New Libraries Under Development
To simplify the use of the SN754410, I’m working on a library for the part called DiffDrive - it sets up the IC as a dual H-bridge designed to run a differential drive robot. It’ s far from being releasable since I don’t have a differential drive with wheels set up yet; soon enough though.
Also, I’m working on a class for the 4411 to simplify 7 segment LEDs. We’ll...
The Next Library
Been putting it off (and still need to find a physical key I need for tomorrow but cannot find) but I my next task is to write a library to use the MCP23017 16-bit I2C I/O expander. Come on *this…
Arduino Pushbutton Library
Just finished a pushbutton library that’s pretty easy to use -
pushbutton trigger(triggerPin, LOW);
declares a pushbutton named trigger on the pin named by the integer triggerPin; the pushbutton is declared as active low. Then, you can check whether trigger has been pressed using
if ( trigger.isPressed() ) { }
The library uses debouncing and internal resistors. An example sketch...
Arduino Ping))) Library
I wrote a library to use the Parallax Ping))) ultrasonic ranging sensor today, just to simplify using the sensors in robotics projects.
The library is available at my arduino page (http://isomk.sdf.org/arduino.html)
and a screenshot of me waving me hand around in front of the sensor:
5 tags
DS1307 Arduino Library
I finished writing a library to use a DS1307 realtime clock in an Arduino. The library is available on my Arduino libraries page: http://isomk.sdf.org/arduino.html
12 hour time modes are sketchy at best since I never use them. If there is interest in 12 hour support, email me at brokenlcd .:[ at ]:. google’s email service
Video of the interface using a 16x2 LCD and thumbstick will be...
stayed up too late...
trying to get this Microchip TC1232 working. At least I have a basic menu structure worked out… but I’ll probably convert it to one that is more abstract.
Arduino Thumbstick Library
Arduino library for Sparkfun part COM-09032, works great with the appropriate breakout board. Checkout the Readme.txt file for usage information.
Available at http://is.gd/801AV - includes Readme.txt and examples. Unzip to /libraries/
hardware tinkering again
Finally got the parts in to start tinkering around in hardware again.
The digikey box:
The sparkfun box:
I basically used part of my tax refund to build up a small parts collection with a lot of common passives and ICs and a couple AVR MCUs, along with some tools.
The resulting workspace:
January 2010
12 posts
tmux
I switched from Ubuntu 9.10 to OpenBSD 4.6 yesterday. For the longest time, I’ve been using GNU screen and it was one of the first things I used to install in OpenBSD. Then I found tmux. I would love to replace all my GPL-licensed software with BSD-licensed software; this is just one more step down that route. tmux also happens to be saner and easier to grok than screen. I’ve heard...
IBM's commercials scare me...
I was watching football with my family this afternoon while getting the new OpenBSD install set up the way I want it. IBM had a few commercials during this time which they proclaimed they were working to share databases together, to link them and share information across databases. Frankly… this scares me. I don’t like data being put together like that. Information is power, and not...
new project
I’m working on a project requiring me to use OpenSSL in a C library; unfortunately the OpenSSL documentation is pretty hard to understand for beginners. To force me to learn how to do it well (and to help learn LaTeX better) I’ve started writing a guide to using OpenSSL in C.
Now let’s see if I actually finish it…
Oh yeah, I still don’t know how to do OpenSSL yet....
xmodmap for the n810
I recently traded my eeePC for a Nokia n810 (aircrack, nmap, and python in my pocket!?) I found that using the shell could be quite a pain because the keyboard does not have keys for escape, tab, or the pipe. Fortunately, the repos have xmodmap (and xev) installed. If all you want to do is to remap keys, all you’ll need is xmodmap.
I remapped the yen key to tab, the euro key to escape, and...
Hardware hacking stalled
With the bricking of the MP3 board (for now), and my inability to get to my tools, for now my hardware hacking adventures are on hold indefinitely. Which is just as well, seeing as how I’m supposed to be working on part of an iPhone app for a friend of mine and that I’m now the technical manager for an independent game project which involves learning UDK, switching back to windows, and...
New MP3 board blog
I branched off discussions about the MP3 development board to another tumblr to keep them separate from this one.
Check it: http://sfe-mp3.tumblr.com
Werd.
12 tags
MP3 development board is working
I have the MP3 development board from SparkFun working… when I got it, it didn’t work and I sort of left it for a while due to some other events going on. I pulled it out of storage recently, charged it, started messing with it, and after tweaking the LCD I was greeted with the SFE boot logo which I had not yet seen!
One of the things that had been a major roadblock in ARM development...
September 2009
1 post
The Smart Card Project
For the past two weeks, I have been working on a new smart card project. I’m using a low-end card for development and testing; it is certainly not a cryptographically strong card. The card is a ZeitControl Professional BasicCard ZC5.4; it has a processor supporting public key cryptography using elliptic curves over the field GF(2^167) which in theory provides the same cryptographic strength...
August 2009
6 posts
So close...
I picked up an episode of a TV show off the iTunes store. I figured since the music was all DRM free, so would the videos. That is definitely not the case. Fortunately, a while back, I had torrented Requiem; however, the latest versions of iTunes render Requiem useless. Using an archival site, I found iTunes version 8.0, installed it on the Windows virtual machine I have on my laptop, and tried...
the Java Tutorials
I started learning Java this week for a project idea I had. I’m using the Java Tutorials bundled with the NetBeans IDE StarterKit DVD. This is the first time in learning a new language (and I’ve used C, C++, perl, python, various flavours of BASIC, PHP, and assembly on a couple different platforms) that I’ve learned about inheritance before learning about basic I/O. Well, to be...
Here is the second track, as promised. I guess I...
I just picked up a new CD today called...
// wrote these on the bus headed in and out of Golden, didn’t get a chance to // submit them before now. Current Location: on the bus in Downtown Denver (39.737 N / 104.993 W ) 20090825 - 1100 MST / 1700 UTC Listening to Vernor Vinge’s SALT (Seminars on Long Term Thinking) talk on why the Singularity* might not happen. To risk restating the podcast, which is available online...
Long Time No Post
Owing to my not-hacker adventures, I haven’t done much with the computer lately. But last night, due to a large bout of insomnia, I reinstalled OpenSolaris on my laptop (I was running kubuntu) and I saved 15G for OpenBSD. We’ll see how things turn out…
Sometimes, Wally, I wonder if I’m like you. Except instead of changing hardware, I change operating systems.
March 2009
8 posts
The Saga of the Secure Data Haven, Act III
With the Soekris and some OpenBSD network security projects that jumped up, I haven’t had time to work on the Secure Data Haven.
One of my fellow HOTSC hackers was able to get Gentoo installed (no hardened kernel yet) by sitting down and finangling with the kernel. The harddrives are currently being encrypted, a process that has taken over 24 hours so far and will likely take up to three...
Useful BIOS Settings for the Soekris net4501
I am using my Soekris net4501 as an OpenBSD VPN / firewall / router (still getting it set up and configured, I hate it when school gets in the way of hacking) and found the following BIOS settings useful:
> set BootDelay=2
> set FastBoot=Enabled
With FastBoot enabled, you need to hit Control + P to enter the monitor pretty much while it’s posting, otherwise you’ll miss it. It...
Updating the Soekris net4501 BIOS
It’s always best practice to make sure your device firmware is up to date. So, when I got my Soekris net4501 and saw it came with BIOS version 1.26a and the latest version is 1.33, I decided to update the firmware. I used the following software (keep in mind I am running OpenBSD 4.4 on the laptop I’m doing this from):
picocom - not in ports but on the web. My terminal software of...