Vehicle speed units
Just an idle thought this morning: wouldnt it be great if vehicles and road authorities agreed to use SI Units to measure vehicle speed?
Just an idle thought this morning: wouldnt it be great if vehicles and road authorities agreed to use SI Units to measure vehicle speed?
I've been coming to my sons class when I get a chance and showing the kids about computer codes. I actually started a CodeClub last year and we were pretty successful, though very limited by my availability -- I was able to run the club for one hour most weeks, so it took us two terms to cover Scratch 1.
This year I've had even less time away from work, but I've had great support from the grade 6 teacher. We plan for him to facilitate the projects in class while I assist via emails and blogs. So: here's my first post.
One of the Huon kids over at Bob's Drone Blog has a really cool Scientific Investigation Awards project - an Accelerometer data logger, or "Accelerologger" (I like the name too!). He's stuck with a small coding bug and has asked for help. I think I see the problem. Wisely, Bob's disabled comments without a login (see my Computing Rule 5), so I'm adding notes here on my own blog.
Today's project was to bootstrap a WiFi LAN connection for Raspberry Pi 2, with a USB WiFi transceiver.
In preparation for some robotics I've dug out my Raspberry Pi 2 B and I'm reacquainting myself with it. Tonight's goal: Boot up an old Raspbian Squeeze SD card and get the Pi to identify on the LAN with a domain-name -- rather than having to learn it's IP address -- using avahi (AKA Bonjour or zero-conf mDNS networking).
After some hacking of my dotfiles and python settings, I lost my nikola
virtual environment (I think it broke after a brew update or something. The hacking's only partly recorded in the issues on GitHub).
But that's no biggie, just make a new one and re-install, right? Well, not quite. The re-install gives you the latest Nikola (great!) and that means I have to review and update my conf.py
(okay...) and figure out runtime errors like this:
[src:?][mjl@milo:~/hax/net/blog/milosophical.me] [07:27](nikola)$ nikola version Traceback (most recent call last): File "/Users/mjl/lib/nikola/bin/nikola", line 11, in <module> sys.exit(main()) File "/Users/mjl/lib/nikola/lib/python3.6/site-packages/nikola/__main__.py", line 171, in main _ = DN.run(oargs) File "/Users/mjl/lib/nikola/lib/python3.6/site-packages/nikola/__main__.py", line 339, in run self.nikola.init_plugins() File "/Users/mjl/lib/nikola/lib/python3.6/site-packages/nikola/nikola.py", line 1077, in init_plugins self._activate_plugins_of_category("SignalHandler") File "/Users/mjl/lib/nikola/lib/python3.6/site-packages/nikola/nikola.py", line 1233, in _activate_plugins_of_category plugin_info.plugin_object.set_site(self) File "/Users/mjl/lib/nikola/lib/python3.6/site-packages/nikola/plugins/misc/taxonomies_classifier.py", line 328, in set_site self._register_path_handlers(taxonomy) File "/Users/mjl/lib/nikola/lib/python3.6/site-packages/nikola/plugins/misc/taxonomies_classifier.py", line 316, in _register_path_handlers doc = taxonomy.path_handler_docstrings[name] KeyError: 'page_index_folder_index'
(well, pooh).
I decided a while back that I wasn't going to meta-blog (otherwise most of my posts would be about blogging!), but I think in this case, Rule 4 will come to the rescue. Anyway at least you know this story has a happy ending, or else I wouldn't be able to add this new_post
!
I started to write about my ${HOME}
directory structure in my post about /home filesystem choices but then it got terribly long and complicated. So I'm writing about it here.
Since switching to a new computer at work I have been reviewing my hodge-podge of directories that I moved from my old work laptop. Same as with my emacs configuration, I like my ${HOME}
to be familiar and friendly no matter what computer and operating system I'm using. Also like emacs at the beginning of this year, it's presently a mess. So I'm documenting how I'd like it to look, be that on my home Linux computer, the Windows mode of the same, or on my work's Macintosh.
This long and detailed article is for my own purpose. Others MAY find it frightfully dull and of little value.
With the release of openSUSE Leap 42.2 just 25 days away, I'm considering to move to it, from my current openSUSE 13.2 Harlequin. I had skipped Leap 42.1 Malachite not for any technical issues with Leap itself, but because I've been pretty tied up learning about Mac OS for work, and because I've been very happy with Harlequin anyway. But it'll reach end of life in Q1 2017 so it's time to upgrade, and I will go to the newest Leap release when it's out. The rolling release Tumbleweed is still not an option for me: not when I have an NVidia GPU and also want to play with CUDA and run VirtualBox VMs.
When I moved house back in 2013, I made a number of rushed decisions and among those was to accept the default filesystem suggestion from Harlequin's YaST installer: use btrfs for the /root
volume, and XFS for /home
. I also put both of these into LVM volumes on the computer's 128G SSD, with about 40G for /root
, 8G for swap
and the rest for /home
thinking "It's LVM, so I can resize the volumes later if this doesn't work out." .... Well, yes, you can resize LVM volumes, but the filesystems contained within behave differently. It turned out that I wanted to grow /root
by taking away some space from /home
, but I hit a snag: XFS filesystems can't be shrunk, only grown. Bummer.
This time around I will take the opportunity of the upgrade to reformat my /home
volume, but the questions are:
/home
is best?/home
?Should I have my home on my fast, but pokey SSD, or should I move it to a slow(er) but expansive HDD? Come to think of it, what about tiered storage in general? (SSD, HDD, "cloud", backups, archives). How should I manage these volumes in a non-intrusive way?
So here are my thoughts and plans.
We're back from a two-weeks family trip to Victoria, along the Great Ocean Road. We planned to do some GeoCaching along the way and we even purchased a store-display model Magellan eXplorist 510 which has support for paper-less caching. It's great, if a bit heavy on the batteries.
The trip was so epic and busy, and we did so many things along the way that we barely had time to stop for caches - we only found six! But it was still a fun diversion.
This article's about the TomTom XL though, our venerable old in-car sat' nav', which needs a little help to do GeoCaching. The device dates from around 2006/2007 I think. Before our trip, we purchased a (long overdue) map update for it, and then the night before we left home I sat down for a bit to re-learn how to upload caches into it as Points Of Interest. This makes driving to the nearest cache much simpler because the TomTom can plan the route. Or else you will see caches popping up along your way if you have a different route already planned.
It's been a month since I started using Spacemacs for my Emacs configuration, and adopted it as my main editor. What's been happening?
Well, mostly not a lot, which is exactly why I wanted to use it. Oh, sure, my commit history shows I've been fairly busy making small adjustments, but they are just tweaks here and there, nothing to blog about.
But, I did sit down this weekend and hack at it so that I can install the same dotspacemacs settings everywhere, which is worth a blog entry.