Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
After 95 minutes on a pleasant ride with temperature around 55 °F, the STK C battery had 0.59 W·h remaining (dark green trace):
Sony NP-BX1 – STK used – Wh scale – 2015-12-12
The last time around, it had 1.85 W·h after 61 minutes. Subtracting the two (and ignoring that it may have started with slightly different charges and behave differently at different temperatures) says the camera used 1.26 W·h = 76 W·min in 34 minutes, which averages out to 2.2 W.
That’s close enough to the “a bit over 2 W” figured from those partial-to-empty measurements for me.
The best STK battery (D) holds just under 4.2 A·h, so its absolute longest run time could be 110-ish minutes. That graph shows the A cell was just about done after 75 minutes, so changing the battery after an hour still makes sense; you never know what will happen during the last few minutes of a ride…
APRS tracks for my rides around Poughkeepsie in early November 2015:
APRS Coverage – Highland to Hopewell – 2015-11
Turning on the topo data and squinting at the Red Oaks Mill area:
APRS Coverage – Red Oaks Mill area topo – 2015-11
The topography isn’t in my favor, with two ridgelines between Red Oaks Mill and the two APRS nodes near Poughkeepsie. APRS coverage southwest of Red Oaks Mill along the Mighty Wappingers Creek (basically, Vassar Road) ranges from spotty to nonexistent, because that route has even worse topography.
Seems to me an APRSiGate in Red Oaks Mill, running Xastir (perhaps headless) on an RPi, conjured from my heap (perhaps with a shiny new TNC-Pi atop the RPi, rather than an ancient Kantronics KPC-9612), and using a vertical VHF antenna in the attic (because lightning), might improve the situation.
That whole project continues to slip into the future, but at least I have more motivation and linkies…
Burnett at Rt 55 2015-11-08 – Yellow 5 s after green
Apparently, NYSDOT’s bicycle safety criteria allow greenlighting opposing vehicles onto bicyclists in the middle of intersections, so there’s no particular urgency to fix this non-problem.
They’ve been “studying” that situation, without contacting me for any further information, since July, so you can decide how much they’ve accomplished thus far. I know NYSDOT employees get offended when you call them liars to their face, but they have never, ever produced any evidence showing that I’m wrong.
This sheaf of tests shows three of the four STK NP-BX1 batteries deliver about 4 W·h during a constant 500 mA discharge, with battery B trailing behind:
After the three most recent bike rides, I popped the partially discharged battery into the tester and used the same test current:
Sony NP-BX1 – STK ABD – charged vs used – Wh scale – 2015-11-22
The longer curves come from the top chart (with different colors), the shorter ones from the partially discharged batteries. In an ideal world, the shorter curves should give the energy left in the battery after the ride, so subtracting that from the before-ride capacity gives the energy used during the ride.
The results for battery A may not be typical, as the camera turned off before I rolled into the garage. The camera may run with a battery voltage below the 2.8 V cutoff in those tests, so it can extract more energy than the tests. The slope of the curve toward the end suggests it won’t get much, but that will still bias the results.
In round numbers, the bike rides required:
A: 3.8 – 0.1 = 3.7 W·h
B: 3.6 – 1.4 = 2.2 W·h
D: 4.2 – 1.0 = 3.2 W·h
I generally turn the camera off during the mid-ride pause (Protip: never wear a helmet camera into a Port-a-Loo), so at least two of the rides have discontinuous usage. I figured the total run time from the video file sizes at the rate of 22.75 min/4.0 GB, blithely ignoring issues like the battery recovering during the pauses, the effect of ambient temperature vs. camera heating on battery temperature, and so forth and so on.
In an ideal world, dividing the total energy by the run time (converted from minutes to hours and not venturing into pirate·ninja territory) should produce a nearly constant value equal to the camera’s power dissipation:
A: 3.7 W·h / 1.25 h = 2.96 W
B: 2.2 W·h / 1.0 h = 2.1 W
D: 3.2 W·h / 1.4 h = 2.25
Ignoring the suspiciously high result for battery A, it looks like the HDR-AS30V really does dissipate a bit over 2 W while recording 1920×1080@60fps video. That’s with GPS, WiFi, and NFC turned off, of course.
Which turns out to be pretty close to the test conditions: 3.7 V x 500 mA = 1.85 W. I could goose the test current to 600 mA = 2.2 W/3.7 V for the next tests, but maybe long-term consistency is a virtue.
It took a while, but the owners of Janet Drive did a commendable job of resurfacing the giant potholes that were consuming the parking lot entrance:
Janet Dr at 708 Dutchess Turnpike entrance – 2015-10-05
That patch covers all the holes, has a smooth surface, and neatly joins the adjacent pavement without huge bumps. It’s entirely possible to do good repairs, if you just hire the right contractor.
Which doesn’t happen if you’re NYSDOT, unfortunately, as they regards a few random hand-tamped blobs on a section of Rt 44 (and Bike Rt 44, for whatever that’s worth) as entirely adequate:
Rt 44 – 695 at Quest Diagnostics – 2015-10-05 – no progress
The sinkhole on Rt 376 that we must dodge maybe four times every week continues to grow:
Somebody who should know better suggested the NYSDOT crew just ran out of asphalt after patching all around the sinkhole that I’d reported back in July, but …
The NYSDOT Bicycle and Pedestrian Coordinator (yeah, she exists) assured me the engineers were studying the signal timing and would contact me directly:
Burnett at Rt 55 2015-08-31 – Yellow 8 s after green with cars
That hasn’t happened after four months, so I’d say NYSDOT uses the word “study” to mean “stonewall”.
A little over a year ago, I bought two Sony 64 GB MicroSDXC cards (let’s call them A and B). Both cards failed after less than six months in service and were replaced under warranty with Cards C and D:
Sony 64 GB MicroSDXC cards – front
The top card (C) is the most recent failure, the bottom (D) is the as-yet-unused replacement for Card D. Note that the difference: SR-64UY vs. SR-64UX, the latter sporting a U3 speed rating.
Note that the failure involves the card’s recording speed, not its read-write ability or overall capacity. Card C still has its nominal 64 GB capacity and will store-and-replay data just fine, but it can’t write data at the 25 Mb/s rate required by the camera… which is barely a third of the card’s speed rating. Also note that the writing speed is always a minute fraction of the reading speed that you see on the card.
I use these in a Sony HDR-AS30V action camera on my bike, so it’s pure Sony all the way. Although I don’t keep track of every trip, I do have a pretty good idea of what happened…
In service: about 2015-07-10
Failed to record 1920×1080 @ 60 f/s video: 2015-09-22
In round numbers, that’s 70 days of regular use.
My NAS drive has room for about a month of video, depriving me of a complete record of how much data it absorbed, but from 2015-08-21 through 2015-09-22 there’s 425 GB from 25 trips in 30 days. Figuring the same intensity during the complete 70 days, it’s recorded 800 to 900 GB of data (including my verification test). With 60 GB available after formatting, that amounts to filling the card 14 times.
That’s reasonably close to the 1 TB of data I’d been estimating for the failures of Cards A and B, so these Sony cards reliably fail their speed rating after recording 750 GB, more or less, of data.
The Smell of Molten Projects in the Morning 