Author Archive
Vehicle Work
by balleman on Mar.27, 2011, under Happenings
Firstly, I’m not a mechanic, but with electrical problems I’m willing to take a stab.
A few weeks ago, I was driving my truck (2005 Ford Ranger) back from a hike with a friend when the engine stopped. I shifted into neutral and tried to restart, and it would crank but that’s it. We got pushed off the road and checked for fluid leaks, etc. Eventually I decided to try the fuel pump shutoff inertia switch and the truck started immediately. I wasn’t completely convinced this was the problem – that maybe whatever the problem was had resolved itself around the time I reset the switch. There was no jolting of the vehicle that should have set off the switch. Researching the problem online, there was some indication that passenger’s wandering feet are sometimes the cause of the problem, as the switch is located in the passenger foot-well, and other indications that if it trips once reset it, if it trips twice, replace it. I was content to reset and forget, as my passenger also indicated he may have been repositioning his feet when it happened.
A week later, the switch tripped again. The same passenger was present, but this time there was no recollection of any bad feet positioning. Resetting the switch was the first remedy attempted and was immediately successful. It was now clear that replacing the switch would be the next step. Researching Ford’s parts database found that in addition to a replacement switch, a “conversion kit” was available that would move the switch from its foot-well location to behind the trim panel (“cowl”) next to the fuse box. I had initially decided against this (it was 4x as expensive), but the Ford dealer indicated that the kit was the appropriate resolution, so I bought one.
Installation was very straightforward, though it is difficult to position your drill in the necessary orientation to drill the pilot holes for the switch mounting bracket. After breaking the head off a ground screw while trying to remove it (remedy: different screw), and breaking the pop-off holding the cowl in place (remedy: zip tie), the switch was finally in place. Upon starting the vehicle, however, the airbag light began flashing a sequence. Panic. Must have drilled through airbag wiring or something. No!
Fortunately, Google translated that code “27” was indicating that the passenger airbag off light was burned out. Interesting coincidental timing. So, I disassembled the portion of the dash and removed the offending keyswitch/light module for a little repair work. I de-soldered the light and replaced it with a resistor and LED. It ended up being a lot dimmer than the factory bulb, but the airbag computer is fine with it.
So far, so good. Hopefully no relapse is on the horizon.
References
My Haynes Repair Manual does little more than acknowledge the existence of the fuel pump inertia switch and air bag system, so here are some of the resources I found.
Gunter Valley Dam
by balleman on Sep.19, 2010, under News, Outdoors
It looks like deconstruction may be commencing at Gunter Valley Dam. Last summer there was an underwater construction company working at the dam, presumably repairing the gates on the intakes. This summer the reservoir has been consistently at very low levels, and in the past few weeks has been drained to the bottom. Sometime this past week, the access road has been improved and earth moving equipment arrived at the dam. A mound of rocks has been placed encircling the intake tower, and an access road for earth moving equipment has been created from the dam breast on its face to the level area near the spillway, and then down to the floor of the valley around the intake tower. There were several groups of people touring the site on my visits Friday and today.
UPDATE 2010-10-22: It looks like whatever the task was is complete for now. The access way down the face of the dam has been closed up and all of the equipment has been removed. A hole has been cut in the intake tower above the lowest intake, possibly for repair of the piping contained within (not sure).
GraphViz
by balleman on Aug.12, 2010, under Technology
A while back I had to diagram interactions between components in a KRB5+LDAP+NFS4 system. Instead of laying this out by hand, I went with GraphViz. I think I had known of its existence, but when I forget what the name of it is, I tend to look up this diagram of Ender stories from Wikipedia. The diagram I made is below, if you happen to have a Celerra laying around. Recently, I’ve started playing with GraphViz again to do some stuff for my current job, but have found out that one thing it doesn’t really do are the directory-tree type layouts one expects to find in most file managers today. Maybe they’ll add that as a different layout engine at some point.
DNSSEC at home
by balleman on Jul.17, 2010, under Happenings, Networking
Since the root zone was signed this week, I spent a bit of time today setting up DNSSEC validation on my home recursive server. It was relatively painless (so far). I did opt to not enable DLV though – not fond of it receiving every host name I resolve.
Resources:
- RHEL RPMs from http://people.redhat.com/atkac/bind/5.6-test/ – if someone finds a better source for BIND 9.7+ RHEL RPMs, I’d like to know. I had no luck building from the Fedora SRPMs.
- http://www.isc.org/community/blog/201007/using-root-dnssec-key-bind-9-resolvers – instructions for setting up BIND to use the root key.
- http://fanf.livejournal.com/107310.html – A more thorough walk-through of setup.
One resource I would have liked to find and could not was a deliberately unvalidatable non-root zone/record that could be used to see a validation failure. If anyone knows of or finds such a thing, please pass it along. Now we get to wait for .com, .net, etc, to catch up to .bg and .uk in the publishing of DS glue for deeper validation.
UPDATE 7/22/10: Just found the following site which makes available bad records for testing purposes: http://dnssec-tools.org/testzone/index.html
Device Convergence: GPS
by balleman on Jun.01, 2010, under Technology
Are cell phones yet to the point where they can replace a hand-held hiking GPS? Up until recently, I’ve been quick to dismiss this notion. The announcement of Garmin’s latest hand-helds that appear to be moving closer to their cell phone brethren has me wondering. Reports of the new touch-screen interface are about as bad as one would expect.
So, what are the issues? I tried my G1 running OruxMaps on a 3.5hr / 10 mile hike in the mountains on Monday to get a better perspective.
Battery Life. It barely survived. I would probably expect twice the battery life from my Garmin GPSMap 76S with a constantly running display. Can the battery life issues be solved with an external AA-based battery pack to keep the cell phone charged? I have no experience with these things. Reviews indicate that ones without regulators aren’t worth much. I might have to try one.
GPS Hardware. Cell phones may have GPS receivers, but it is not their primary function. Most Android phones I’ve looked at seem to use the Qualcomm gpsOne chipset instead of a dedicated chipset such as the oft-mentioned SiRFstar III. This is a cause for concern, since gpsOne currently seems to lack support for WAAS and likely is not as sensitive as the SiRFstar. The upside of gpsOne is that AGPS will provide a faster lock when within range of the cell network.
Usability. Another major hurdle is the availability of high quality GPS software for the phone. I’ve tried Maverick Lite, OruxMaps, and My Tracks and found them all to be lacking the necessary features of a hand-held GPS. My Tracks is the Google-sponsored outdoor activity tracking app that was very recently open-sourced. Maverick and Orux both provide offline map access (another must), but they seem to accomplish this with saved graphic tiles and not vector data as would be desired. Any new GPS solution I get should have high-resolution topo maps included.
Durability. Hand-held GPS receivers tend to be waterproof and a bit rugged. I’ve dropped my GPSmap 76s a number of times – and it once fell off my bike at 15+ mph. There’s no way any phone I’ve owned would be happy with that kind of treatment.
Bottom line? Not sure yet. I do think the concept of a hand-held GPS is already starting to fade. I’m not ready just yet to give mine up in favor of the cell phone. I hope the newly open-sourced My Tracks starts gaining some useful hand-held features.