Wifi-less Nexus 5

A couple days ago, some time between 6-9PM, the wifi on my Nexus 5 turned off, and wouldn’t turn back on again.

Rebooting the phone didn’t help.

Attempts to re-enable wifi (Settings/Wi-Fi) just ended up timing out with no results, and the wifi disabled itself again.

Bluetooth still works.  Cell service and data still works.  Just no wifi.

After doing a factory reset yesterday, my Nexus 5 started behaving even more strangely.  There were lots of random freezes and spontaneous reboots while using the phone.

Even more strangely, sometimes the wifi would come back on, but only for about 30 seconds or so.  Very intermittent and not at all reproducible.  Wifi would flash back on briefly after a reboot, but then get disabled again.  Most times wifi just stays disabled.

Time to think about getting a new phone I think.  If it was just the lack of wifi, I could probably deal with it.  The random freezes and reboots are more problematic though.  This one has lasted 4 years (a refurb I received when my original developed screen issues and then needed a repair for the infamous power button issue), which is pretty impressive for cell phones these days.

I suppose this might be a good opportunity to give LineageOS a whirl to see if that will help with the wifi issue.

Update: After a few more reboots, the phone stabilized and there weren’t any more random freezes or reboots.  Still no wifi though.  Installed LineageOS onto the phone, which went well.  Didn’t resolve the wifi issue though, so it’s probably hardware related.  On the plus side, the phone is now at Android 7.1.4 (Nougat).

Emacs-ing and Lisp-ing

Over my decades of using computers, I’ve made more than a few attempts at using Emacs, some more successful than others, but always ended up reverting back to something else like Geany or these days, Atom.  When I’m in the command line (which is fairly often), vi/vim is usually the editor I use, mostly because it’s quick and easy to start up.

A little while ago, got the bug to start using Emacs again when I got introduced to Spacemacs.  Although it also has vim keybindings, I’m mostly using Emacs keybindings.  I’m working hard to make Emacs my primary editor (mainly code editing at this point), and will try to work in some of the many other things Emacs can do later.  I’ve heard a lot of good things about org-mode, which is on my list of things to learn.

One thing that’s different about my attempt to immerse myself in Emacs this time around is that it also seems to have come with a desire to learn Lisp.  No idea why, or even what I’d do with it, but it’s prompted me to acquire a few Lisp books, including one on Emacs Lisp and Land of Lisp.

Where this will take me, I’m not sure.  I haven’t spent a whole lot of time with Lisp yet aside from reading a few chapters about Emacs Lisp.  I don’t have any projects on the horizon that I can see doing in Lisp just yet, but you never know what will come up.

xkcd: Lisp

Beacon teardown

At the AAPM 2018 annual meeting, attendees received a BLE (Bluetooth Low Energy) beacon that was used to track attendance at sessions for continuing education and SAM (Self Assessment Module) credits.

Little blue beacon
Little blue beacon
Little blue beacon
Little blue beacon

The website stamped on the beacon redirects to a company called Gimbal where you can purchase the beacons for $5 each or get a whole case of 1650 for the same unit price.  They also provide web based software for managing the beacons.  The manual for the beacon contains some specs, instructions for using the beacon with the Gimbal software, and links to API docs for creating apps to use with the beacon.

The beacon opens pretty easily using a quarter.  Most of the beacon’s innards are taken up by a CR2032 coin cell that powers a tiny little circuit board underneath a plastic cover.

Beacon innards
Beacon innards

A bit of careful prying to release the cover (also held down by a couple dabs of adhesive) reveals the circuit board.  Three contact pads presumably for testing/programming are easily visible.

Beacon innards
Beacon innards
Beacon innards
Beacon innards
Beacon PCB
Beacon PCB

Not much identifying info on the little IC at the heart of the beacon.
P36V G4

Guessing the first number would be a product identifier with the next line (2500D0A) maybe being a date code.  Google led me to a reasonably informative post about the beacons.

Seems to be a fairly simple device and beacons in general might be something fun and interesting to get into.

AAPM 2018 Day 4

Final day of the AAPM 2018 Annual Meeting for me today.

The Kereiakes Memorial Lecture: Designing Pediatric Imaging to Achieve the Best Benefit/Risk for Our Patients had some great speakers who reminded us that we need to work toward maximizing the benefit:risk ratio to patients from medical imaging, and not just minimizing the risk.

The other sessions today were about artifacts in CT, MR, and mammography, CT protocol management, and fluoroscopy technology.  All good sessions.

As a “down in the trenches” medical physicist, it’s always good to attend these kinds of meetings.  Not just for the professional and scientific sessions, but also for the networking opportunities.  I need to make more of an effort to make it to the AAPM meetings on a more regular basis.  10 years is far too long to go between meetings.  After the past few days of sessions, I’m realizing how stagnant my knowledge of things, and perspective of the field has become even though I try to keep up by reading journal articles.

Off to the airport tomorrow, and then back to work.  After being off work for the past three weeks, there will be a lot of catching up to do.

AAPM 2018 Day 3

I really like going to these meetings.  I can spend all my energy and brain power soaking in information that I’ll put to use at work.

Today was sessions on breast imaging, the latest in PET imagers, and updates on the ACR accreditation programs.  All good sessions that I really enjoyed.

At the lunch break, there was a meet-the-editors event at the Wiley booth where people could meet the editor-in-chiefs (EIC) of Medical Physics and Journal of Clinical Applied Medical Physics.  Nice event with about 8 or 10 people coming by.  They asked the EICs some good questions.  I asked if AAPM would continue to release yearly ISO images of Medical Physics like they did when the journal was with AIP, but sadly it looks like under Wiley, they won’t be doing that anymore.  It’s too bad.  It was pretty handy when I needed to look up an article.  Just mount the ISO image and navigate down the directory tree to the article I needed.  It was usually faster to do that than fire up a browser and dig up the article online.

The Night Out event at the Country Music Hall Of Fame and Museum was pretty nice.  The museum has all kinds of artifacts, displays and exhibits about the country music world.  Pretty cool place. 

Physicists in the museum lobby
AAPM 2018 Night Out in the museum lobby

Last day of the meeting for me tomorrow.  It’s been a really good meeting for me, but I’ll be glad to get back home on Thursday.