All posts by Matthew Gillespie (admin)

What?!

Blast you, PinEntry!!!

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Following a recent update to my Gentoo installation at work, I found myself pestered by PinEntry acting as my new SSH Authentication Agent. Formerly, I used the normal ssh-agent, as it’s console only and doesn’t steal focus on the terminal window I’m currently working in.

 

Popups Must Die

A quick look at the process-list shows why:

gillespiem@kovacs2 ~ $ ps axu | grep gpg-agent
30847 ?        Ss     0:00 gpg-agent –daemon –enable-ssh-support –write-env-file /home/gillespiem/.cache/gpg-agent-info

 

The GPG-Agent is being run with the –enable-ssh-support flag. Here’s how you can turn it off if you’re using XFCE4:

The script /etc/xdg/xfce4/xinitrc handles chosing the correct authentication agent at line 129:

129 # launch gpg-agent or ssh-agent if enabled.
130 ssh_agent_enabled=`xfconf-query -c xfce4-session -p /startup/ssh-agent/enabled 2> /dev/null`
131 if test “$ssh_agent_enabled” != “false”; then
132     # if the user has pam_ssh installed, it will start ssh-agent for us, but
133     # of course won’t start gpg-agent.  so, if ssh-agent is already running,
134     # but we want gpg-agent (and that’s not running yet) start gpg-agent
135     # without ssh support
136
137     ssh_agent_type=`xfconf-query -c xfce4-session -p /startup/ssh-agent/type 2> /dev/null`
138     if test -z “$ssh_agent_type”; then
139         if which gpg-agent >/dev/null 2>&1; then
140             ssh_agent_type=gpg-agent
141         else
142             ssh_agent_type=ssh-agent
143         fi
144     fi

To pass the first test (line 130), set ssh-agent to be enabled by running this (it only needs to be run once):

xfconf-query -n -t bool -c xfce4-session  -p /startup/ssh-agent/enabled -s true

To pass the second test (line 137), set /startup/ssh-agent/type to … well, pretty much anything will do, as it only tests that it’s a non-zero length string – I’m setting it to “ssh-agent”:

xfconf-query -n -t string -c xfce4-session  -p /startup/ssh-agent/type -s ssh-agent

If you’re currently in XFCE4, kill gpg-agent and restart XFCE. You’ll find when you return, ssh-agent will act as your SSH Authentication Agent, and gpg-agent will handle GPG specific transactions.

BrainDeadTip, What?!

BrainDeadUpgrade

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Not much has happened project-wise in the last few weeks. Any free time I’ve had has gone to updating the wireless firmware to capture MAC addresses and pass them off to an Elgg plugin I’ve written. I’m still waiting on a box of 10 Servo’s from China to continue my RC Car modification project.

I’ve also got plenty of work to do around the house until May.

But now, after almost 4 years, I’ve decided it’s time to spruce up BrainDeadProjects.com.  I’m retiring the  glowing brains that have been the personification of BrainDeadProjects for these past few years. Sure, remnants will probably remain (the favicon for instance)… but now let me introduce you to “Tin Can Head“:

Tin Can Head is the work of LogoDesignCreation.com. Give them your idea, and for a modest amount  (under $60), they’ll propose a few design ideas for you. Turnaround is fast, Wired.com gave them a good grade, and overall I have to say that I’m pretty satisfied.

More project updates soon, in the meantime stare at the glowing brains of Tin Can Head.

Electronics, TI Launchpad, What?!

Every Police Car needs flashing lights

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This weekend didn’t afford me enough time for personal projects, but I did have a few moments to solder connections onto the LED system on the RC police car I’ve been modifying. (I also drilled out the rear window).

Controlling the LEDs is simple: they  all share a positive terminal, bring a cathode to ground and you have light. Controlling the lights via an MSP430 is simple – set the connected pin to be an output, and set the pin low. The LED board has built in resistors, so there’s no need to add them.

There are 8 LEDs, 4 of which are independently controlled:

  1. The two (2) Headlights and two (2) Brake lights
  2. The Blue lightbar
  3. The White lightbar on the left
  4. The White lightbar on the right
  5. The Red lightbar

With the soldering of connectors finished, I hooked them up to the Launchpad and made a quick modification to the Hackaday.com Hello World program –  this time  setting 5 pins as outputs, and turning on all the lights except the blue and white lightbar on the left. I toggle the entire lightbar approximately every ~6th of a second.

The specific pins to control each light will definitely change in the future, but seeing blinky lights in the meantime is always fun. I’m happy with my choice of this particular RC car – having 8 LEDs makes it real easy to display status codes and will definitely help with debugging later.

Next up: connect a PING sensor to  a small servo to the roof … once my box of servos arrive.

Electronics, TI Launchpad, What?!

RC Car no longer under your control.

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I’m in the middle of reading MSP430 Microcontroller Basics, which I’d picked up for some insight into the inner workings of the MSP430 line from Texas Instruments (especially the MSP30G2231, one of the controllers included with the Launchpad Emulator board). Unfortunately this coincides with a lot of overnight work at the office, so I’m still making progress (albeit slowly) with the RC Car modification and rebuild.

Patrolling a messy desk.

In the past few weeks, I’ve done a bit of work/learning with a couple of Parallax sensors  – namely the PIR and the PING. I’ve ripped out the stock board and replaced it with a SN754410E Quad half H-bridge, and began cleaning up some of the poor solder joints. More on all of this in a few weeks, but in the meantime let’s tryout my new Toshiba Camileo X30 (sorry about the low light) and Cinelerra, and look at using the MSP430’s TimerA for pulse width modulation:

More in a few weeks…