Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
The Poughkeepsie Bridge always looks good in its necklace lights:
Fireworks Moonwalk – Poughkeepsie Bridge
Each catenary carries a string of lights that produces a slight double-exposure effect. It’s not your eyes, there really are two closely spaced lights.
The moon hadn’t yet risen, so the southern sky got completely dark. That makes for an easy-to-assemble south-facing panorama with Poughkeepsie on the left:
One might reasonably conclude all six came from the same factory; the STK B battery looks like a dud. The two replacement batteries from STK performed slightly better than the first pair.
The Wasabi and SterlingTEK batteries all carry a 1600 mA·h rating that’s far in excess of their actual 1000-ish mA·h performance. If they were advertised as 1.0 A·h batteries, they’d meet their specifications (for small values of “meet”), but nobody would buy a second-tier battery with less capacity than the Sony OEM battery’s 1.24 A·h.
If you rummage around in previous posts, I did verify that battery capacity does increase with decreasing test current, but definitely not by the 60% needed to reach 1600 mA·h.
Because most devices these days operate at constant power from a boost supply, presenting the results against a watt·hour scale would make sense:
They should survive for hour-long rides with the GPS tracker turned off, which is about as much as I want to ride at once. I’ll eventually autopsy the STK B battery, which won’t last all that long.
Credit where credit is due: after I sent the first test results to STK, they sent a pair of replacement batteries and, based on the second test results, refunded the entire purchase price. I’m reluctant to give a five-star rating for customer service, because shipping mis-advertised products should carry a zero-star rating.
Sony NP-BX1 – Wasabi AB CDE FG – when new – 2015-11-03
The red traces are the original units (AB, January 2014), the blue traces are the next three batteries (CDE, October 2014), the purple traces are the new pair (FG, October 2015), and the green trace is the OEM Sony battery, all tested when more-or-less new.
So, about the same as before, not as good as the first pair.
That may show a year on the warehouse shelf doesn’t affect lithium batteries very much, because the date codes atop the batteries, labeled in order of arrival:
AB = BMK20
CDE = BNI18
FG = BNI13
Assuming my interpretation of the date codes is correct, the last two digits indicate the day of manufacture: the most recent two batteries (F and G, arrived a few days ago) are five days older than the previous three (C, D, and E, arrived Oct 2014); all five were manufactured in September 2014, a bit over a year ago. The first two were built in November 2013.
Huh…
The problem with lithium batteries is that no two devices use the same battery, even when the batteries are functionally identical, so distributors must stock an acre of separate items, each of which move pathetically few units. Perhaps the top ten items make up for the rest?
Because the first pair of Wasabi NP-BX1 batteries for the Sony HDR-AS30V camera faded to the point where they weren’t useful for a typical bike ride, I bought a pair of SterlingTEK (a.k.a. STK) NP-BX1 batteries that, like the Wasabi batteries, claimed to have a 1600 mA·h capacity. These are “second tier” batteries, not the cheap eBay crap I’ve already dismissed, and run a bit under $10 apiece.
Here’s the picture from their product description:
SterlingTEK – STK NP-BX1 battery – as advertised
Here’s what arrived:
STK NP-BX1 batteries
Huh.
That’s a red flag, right there. It’s remarkably tempting to ship a good product for a while, then swap in much cheaper junk that can ride on the good reviews. Not saying that’s what happened, but it’s a possibility.
Here’s how they performed:
Sony NP-BX1 – Sony Wasabi STK – as received
The red and blue curves show that the STK batteries produced less than 1000 mA·h in their first two charges, with the blue battery (I labeled it B) showing considerable variation that suggests it’ll suffer early failure. The green curve shows one of those Wasabi batteries and the purple curve is the OEM Sony battery, both in as-received condition.
SterlingTEK will send two more batteries, in the belief that I received two sub-standard samples. We shall see…
All the tests are at 500 mA, approximately half the camera’s load. Oddly, the numeric values along the mA·h axis work out pretty close to the actual runtime in hours:
Sony – 1:30
Wasabi D – 1:15
Wasabi B – 0:40
Given that a typical bike ride takes an hour, the two year old Wasabi B battery’s 40 minute runtime isn’t useful. The Wasabi D battery is a bit over a year old and looks very much like the B battery did last year.
The Wasabi batteries march through the camera and charger in order, so each one gets used about once a week. The Sony battery gets used once every half-dozen complete cycles, just so I have a standard “good” battery.
The Sony and Wasabi B cells over the course of two years:
Sony NP-BX1 – OEM Wasabi – 2015-10 2014-10 2014-01
Much to my surprise, the Wasabi batteries started out slightly better than the Sony OEM battery, at least as measured by the available voltage and energy. The camera runs from an internal switching power supply, so the area under the curve (basically equal to energy in W·h) above the cutoff voltage is all that matters.
In round numbers, I can expect 100 cycles out of each battery before the run time drops below the ride time; at $10/battery, that’s a dime a ride. Any claims that the batteries can be recharged “1000 times!” may be true, but they’ll have a useless fraction of their original capacity by then.
In 1991 we lived in Tolland CT, where I took one picture of a maple twig every week:
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That was with a film camera, of course, with negatives. I assembled the printed images into a poster and eventually (perhaps in 2001) scanned / digitally photographed them four-at-a-time, saved the result as a 330 MB Photoshop file with one 2×2 group in each of 13 layers (there are 50 images, probably because vacations), and burned that to a CD.
All I can say: it must have made sense at the time.
Anyhow, here in the future, I found that CD in a pile destined for the shredder, which shouldn’t ought to happen without some attention.
Here’s how I extracted the separate images from that file into standalone JPEGs, cropped them to a uniform size, and smushed them to suitably low quality:
convert A\ Year\ in\ the\ Life\ of\ Tolland\ CT\ -\ 1991.psd -quality 95 Tolland-1991-%02d.jpg
for f in {01..13} ; do convert Tolland-1991-$f.jpg -crop "1212x1775+0+0" img-$f-0.jpg ; done
for f in {01..13} ; do convert Tolland-1991-$f.jpg -crop "1212x1775+1212+0" img-$f-1.jpg ; done
for f in {01..13} ; do convert Tolland-1991-$f.jpg -crop "1212x1775+0+1775" img-$f-2.jpg ; done
for f in {01..13} ; do convert Tolland-1991-$f.jpg -crop "1212x1775+1212+1775" img-$f-3.jpg ; done
for f in {01..13} ; do for g in {0..3} ; do convert img-$f-$g.jpg -crop "1100x1650+50+50" out-$f-$g.jpg ; done ; done
sn=1 ; for f in {01..13} ; do for g in {0..3} ; do printf -v dn 'Tolland-1991-Maple-%02d.jpg' "$(( sn++ ))" ; convert img-$f-$g.jpg -crop "1100x1650+50+50" +repage -rotate 90 -define jpeg:extent=200KB $dn ; done ; done
Then WordPress assembles the 50 images into a slide show.
Of course, it didn’t go quite as smoothly as all that, but it took maybe half an hour of fiddling to get it right by iterating on the commands until I liked the results. One might tweak the exposures and suchlike, but that’s in the nature of fine tuning.
The Sony HDR-AS30V has extremely high audio gain, which is precisely what you need for the mic on an action camera. It sends that audio, along with the video, through its HDMI output, so when you drive a display from the camera in enclosed space, the audio is REALLY LOUD and causes severe feedback. For obscure reasons, given the staggering cost of the venue’s AV system, there’s no way to mute the audio channel of the video input when you’re also using a mic attached to someone giving a presentation.
The obvious solution, a shorted jumper (formerly an earbud plug) in the external mic jack, looked like this:
Sony HDR-AS30V – Dummy external mic
Contrary to what I expected, the camera doesn’t disable the internal mic with the jumper in place. The amp probably uses an analog multiplexer, rather than a mechanical switch, and even an off-channel isolation of, say, 76 dB (from the MAX4544 spec, for example) isn’t enough to completely mute the mic. You could, given sufficient motivation, measure the actual isolation, but the surviving audio isn’t subtle at all.
The not-obvious solution turned out to be putting the camera into either single or interval photo mode, rather than the movie mode I use for bike rides. It seems that when the video format doesn’t require audio, the camera either disables the audio inputs or (more likely) just doesn’t include audio data in the HDMI output.
Which produces exactly what I want: a video output with no accompanying audio.
The Smell of Molten Projects in the Morning 