Archive for the ‘electronics’ Category.

Nexus 5 Protection Efforts

After soundly breaking my Nexus 4 (it’s now listed for auction on eBay for parts) I ended up purchasing a Google Nexus 5 as a replacement. On the recommendation of my friend Laurence (and after lots of research) I chose to add a case and screen protector in efforts to keep it from breaking when I drop it. With the Nexus 4 I’d used a neoprene pouch when carrying it in my pocket, but this had the flaw of leaving the phone exposed around the times when I’m using it, which is how I broke it.

The protection chosen is a cheap ($9.89 via Amazon) Diztronic thermoplastic polyurethane (TPU) case that covers five sides of the phone and a Skinomi TechSkin screen protector ($9.95 via Amazon). The screen protector seems a bit expensive, but Laurence has found it to provide a great deal of protection, so I’m giving it a go. Hopefully this will keep the phone looking and functioning nicely for a few years.

For a few years I’ve been using Pelican plastic cases to keep my phones safe when biking. A Pelican 1015 kept the Nexus One safe and dry and a Pelican 1020 took care of the Nexus 4. The Nexus 5 is larger than both of these and won’t fit in either case that I have, so I’m hoping that the more traditional cycling protection of a thick plastic bag, coupled with the case and screen protector, and stashed a bit more deeply into my pack, will keep everything intact. The lack of plastic box should make the phone more audible when ringing, something that Danielle will surely like when she tries to call me.

While it’s only been a few hours since application, thus far I’m happy with the screen protector and case. The case fits snugly, doesn’t interfere with connectors, and the buttons are easily usable through it. One small scuff from my finger nail is visible when the screen is off, but turned on it’s invisible. It also is sufficiently slick in use to not have the traditional dragging-a-finger-on-plastic-wrap feeling that other screen protectors suffer from. I’m quite sure that more of these small scuffs will appear with daily use. This case also has the upside of keeping the camera’s lens or screen from resting on whatever surface the phone is set down on, hopefully keeping them nice for longer.

Now to hope I don’t break this one…

Breaking My Phone

This evening while changing in the bathroom the BK Training facility I dropped my phone, a 13 month old Google Nexus 4, shattering the outer glass / digitizer. It appears that the phone fell screen down, with one side landing slightly before the other, and the non-slip rough surface tile in the bathroom did a fine job ensuring the screen was ruined. I’d had problems with the slipperyness of the phone before, but usually my hand was moist enough to keep a good grip on it. A couple times this winter the dry skin on my hand has contributed to my dropping it, but previously it’d only been on soft surfaces. This time it was done in.

At this point the touchscreen doesn’t work, so I’m shopping for a new phone. I may replace the screen then sell the phone, but at this point I’m most concerned with getting a working phone quickly. I guess it’s time to get shopping for a new phone, see if its available locally, give screen protectors some thought, and dig into wiping my phone without use of the touchscreen.

Raspberry Pi MAME Cabinet Retrofit Notes

Back in 2000 I built a MAME cabinet, but I haven’t used it much lately. I want to retrofit it with a higher resolution LCD screen and updated hardware and OS, so I’m thinking that a Raspberry Pi and a cheaper LCD would work well. These are my work-in-progress notes for this project:

Cabinet Changes:

  • Remove exhaust fan / temperature activated relay.
  • Remove ATX switches and lights; maybe replace with something to toggle the Raspberry Pi on and off.
  • Remove PC, use base plate to mount power supplies / Raspberry Pi and supporting hardware?
  • Swap Hagstrom KE-72 for something USB.
    • Needs to support trackball.
  • HP ZR2440w monitor in place of CRT. ASUS VS24AH-P? 1920×1200 max from Pi.
  • Need to rework power on/off stuff due to Raspberry Pi not having any way to actually shut itself down.

Raspberry Pi Hardware:

  • v2.0 board.
  • Enclosure.
  • Powered USB hub.
  • WiFi adapter: Cheap dongle; Adafruit sells one.
  • Large SD card: 128GB?

Control Panel Hardware:

  • Replace Hagstrom KE-72 with I-PAC or Hagstrom KE-USB36 which may be an almost drop-in replacement.
  • Currently have 39 inputs. Can I work with only 36?
  • Panel-mount USB B.

Order of work:

  1. Get Raspberry Pi.
  2. Validate MAME functionality.
  3. Update monitor.
  4. Update control panel.

UPDATE: After the purchase of a Raspberry Pi and some extensive testing, the hardware seems nice but not capable of running MAME at any appropriate speeds. Thus this project is shelved for the time being.

Garmin Edge 500 Time Issues during Lumberjack 100

After getting back home from completing Lumberjack 100 I was excited to review the logged data from my Garmin Edge 500 bike computer. A few times during the ride the unit lost GPS signal, but as I’ve had this happen on other rides without issue I didn’t pay it much attention. Unfortunately, it looks like this time the data really went odd. After poking with the data and attempting to correct it in Ascent I downloaded Fit File Repair Tool to see what it could tell me.

As shown in the screenshot above (click to embiggen), roughly 15.52 miles in, at 44.2119°N 86.1295°W, just beyond the Steinberg Road crossing in Road Monkey during my first lap (map here), the recorded time suddenly jumped from June 15, 2013 to October 19, 2019. This explains the strange duration I’d been seeing in analysis software, with everything from Ascent and Strava both reporting an elapsed time of around 55619:03:11, the length of a ride which I don’t quite think the Edge 500’s battery would endure, but which matches the 6-some year offset. Weirdly, Garmin Connect doesn’t show the issue (link), almost as if they filter out this problem.

When this issue occurred my Garmin was running firmware v3.00, something which I was hesitant to change soon before the race. Since the changelog to v3.20 only lists two minor changes which aren’t useful for me (power meter serial number display and a change to support manufacturing) I didn’t see a good reason to rush to upgrade. It’d also worked otherwise well for long rides, so I didn’t anticipate any problems. I upgraded the unit to v3.20 today and I’ll see if similar problems arise, but I can’t imagine I’ll be doing that length of ride any time soon, so it’ll be hard to get an equivalent test.

If any of you wish to review this damaged FIT file from Lumberjack 100 it can be found here: svigneau_2013_lumberjack100.fit.

Warranty Replacement Garmin GSC 10

I’m a strong proponent of using a Garmin GSC 10 Speed/Cadence Sensor to eliminate under-measurement when using a Garmin Edge 500 bike computer. When I found the GSC 10 on my Salsa El Mariachi single speed to have stopped recording wheel revolutions I was a bit disappointed. I didn’t really want to spend $40 – $50 on another one, so I phoned Garmin and asked about a replacement.

I found that the reed switch on the extended arm (the part that detects wheel rotation) would only intermittently trigger if a large neodymium magnet was rubbed on it. Tapping on it didn’t free up the apparently sticky reed switch either, so I figured it to be dead.

Garmin has been good to me in the past about warranty issues (namely, replacing an Garmin eTrex Legend whose input stick ceased working) so I decided to give them a call. After talking with the phone support person for a few minutes and explaining the problem he agreed that it seemed defective and offered to send out another. It arrived today, and now my single speed has a working sensor again and should properly measure distance on trails.

Google Nexus 4 Supports GLONASS (and GPS)

A few days back Jeff pointed out to me that the Google Nexus 4 supports both GPS and GLONASS for satellite-based geolocation. I hadn’t noticed this before, but sure enough as seen above in GPS Status & Toolbox there they are. The GLONASS satellites are the boxes shown in grey, where the GPS satellites are the green circles.

This helps explain why the device is so good at getting fast location fixes and also why it works so well for my amateur mapping work. I’ve wanted a GLONASS-supporting device for a while and now I have one. Yay!

(This screenshot was taken while logging the location of Stony Creek’s Trolly Trails so I can commit the route to OpenStreetMap.)

 

More GPS Goofyness

This evening I was playing around with drawing custom courses that can be loaded into a Garmin Edge 500 and used to provide turn prompting while out riding. This isn’t quite turn by turn directions, but upon reaching a certain point it’ll provide notification that one should turn, look for a hazard, etc. To test this I set up a neighborhood route, out Philadelphia Court and out to some main roads, winding around through some other neighborhoods, and back.

Not long after departing on a test ride it correctly informed me that I should turn right out of the driveway, but then gave an an off-course notification and the prompting no longer worked. After I got back home and reviewed the data the image above is what I found. Lots of garbage data scattered around the neighborhood.

This is just one of the many little quirks that I run into when using a GPS for data recording. Despite indicating that it’s receiving a solid signal it’ll still occasionally go funny and produce garbage for a little while. I’ll have to give this a different test another day. Maybe I’ll head out for a ride on Sunday and test the prompting on one of Bob’s routes…

2013 LOHS Winter Race

This morning I took part in the sixth annual Lake Orion High School Winter Race; a cross country (XC) race around the school’s grounds and mountain bike trails. The trail conditions were perfect for all kinds of bikes, and my fatbike definitely wasn’t necessary. It sure didn’t hurt, though, and made for a fun ride. Per usual I didn’t have to brake much, as the increased rolling resistance (the front tire is 4 PSI, rear was 6 PSI) allowed me to stop pedaling before most corners, roll through, then keep going.

Being the only person on a fatbike I won the Fatbike category by default. Had I raced in my appropriate Sport class I would have taken third out of four. (Official results here.)

I really liked the route, as it avoided many of the hard/slick climbs that can be found on the school grounds and instead opted for a nice rolling route. My only complaint would be the overall length of the race, as doing three laps I was only riding for ~46 minutes. I think we could easily have gone to four or five laps and still been sane for a winter race.

GPS data of my ride today can found here on Strava. It seems that for the last third my HRM acted up again, radically under-recording things.

On the way home I noticed that there is now a Great Lakes Coffee location along M-24 / Lapeer Rd. and stopped for some coffee. It seems to be almost colocated with a Kensington Church location so I braced myself for a bit of proselytizing, but I was pleasantly surprised to instead encounter some nice folks who made me a good cup of coffee.

The photo above is one of the first actual-use images taken with my new camera, a Fujifilm FinePix XP50 ruggedized camera. I bought this to replace my aging Olympus Stylus 850SW as my carry-everywhere camera. The Olympus served me very well, but I was wanting something with better low light performance, a more capable movie mode, and SD cards. Finding a good deal on the XP50 I figured I’d give it a go. Its ~20g heavier than the Olympus and lacks the nice auto-retracting metal cover for the primary lens, but I think it’ll work out well. I’ll know for sure at the end of summer.

GoPro HD Hero 2 Soldering

Steve Kinley with MiSCA was having problems with his GoPro HD Hero 2 camera and set about disassembling it, but in the process inadvertently disconnected the wires from the back side of the internal speaker. Knowing that I’ve done a bit of electronics work he asked if I’d take a look at it, so I did.

In the end I was able to reattach the wires to the speaker, and also fix the other end of one wire which was damaged during the original issue and came off of the PCB during reassembly. This was quite a pain, but it all seems set now. Hopefully it’ll keep working right for him.

Pelican 1020 Case for Google Nexus 4

For the last few years I’ve been using a Pelican 1050 case to carry my Google Nexus One phone when biking, hiking, mapping, etc. This past Monday I received my new phone, a Google Nexus 4, and set about fitting it into a new case. The Pelican 1020 is the closest fit, but unfortunately it’s just slightly too tall to hold the phone flat inside the case.

Setting the phone at a slight angle allows it to fit nicely in the case, and with the addition of two block of neoprene foam rubber (layered and held into place with contact cement) the phone is soundly secured in the case. The block near the top of the phone holds it from rattling around, and the thicker block near the bottom keeps the phone from sliding around if dropped soundly on its face.

This is not the most elegant solution, but until I can find a better-fitting case it’ll do. I’d love one which allows the phone to nestle in as nicely as the Pelican 1050 did needing just a bit of extra foam, but that’ll take some digging, if they even exist…