Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
A friend now owns my trusty Canon SX230HS camera, but, given the restrictions on shipping lithium batteries, we agreed there was no point in transferring ownership of my nearly dead batteries.
For completeness, their final state:
Canon NB-5L – 2018-03-25
The original Canon OEM battery (orange curve) looms above all the offerings from various Amazon sellers.
All of the local turkeys come together during snow storms, often lingering in the circle of pine trees in our back yard to get some protection from the wind. Mary spotted a Cooper’s Hawk in the midst of the turkey flock, with its wings spread around a recently captured meal:
Hawk with squirrel – wings spread
When she first saw it, the hawk had its back to us and looked like a cluster of dead pine branches; the recent back-to-back storms have cleared out quite a bit of deadwood.
When I quietly opened the back door for a better view, the hawk noticed and gave me the stinkeye from 100 feet away:
Hawk with squirrel – 2
The flock had moved out of the pine circle to surround the hawk and examine the situation, although they weren’t harassing it:
Hawk with squirrel – 3
We’ve counted 27 turkeys, more or less, on some days, well and truly outnumbering the hawk:
Hawk with squirrel – overview
Fortunately, turkeys feed mainly on insects and seeds, rather than tearing into carrion, so they’re not competing for the prize:
Hawk with squirrel – detail
Shortly after I gave up and went back inside, the hawk sank her (?) talons into the squirrel, lifted heavily into the air, circled around the pines, and flew off toward the Mighty Wappinger Creek out back.
A casual search suggests both the hawk and the squirrel weigh about 1 lb = 500 g: I’ll never complain about heavy grocery bags again!
My original idea for the APRS + voice gadget was a snap-in battery pack replacement holding the circuit boards and connected to an external battery pack. A trio of deadWouxun radios, plus the ready availability of 18650 lithium cells, suggested putting two cells in the backpack, along with the circuitry, and skipping the external pack.
The grid is parallel to the case body and centered left-to-right, with a Y grid line set at the front face of the pack, where it’s also flush with the lid surface. You can read off the coordinates of all the points, feed them into your CAD model, and maybe, with a bit of care, get something 3D-print-able.
Haven’t used it yet, but it’s bound to come in handy at some point.
The faint purple disk dead center in the image comes from the Pixel XL’s IR laser (so they say) rangefinder reflected in 1950-era window glass. Another image, with the Pixel pressed flat against the glass, shows two reflections:
Snowfall – Pixel IR rangefinder reflections – detail
Mary took a similar picture in the morning, standing in the patio just outside the front door:
Snowfall – Front yard – day
The downed branch will require some chainsaw work, but, if past experience is any guide, the sticks will vanish from the end of the driveway within a day. The previous storm dropped a tree on the power lines half a mile northward, leaving us in the dark for about 18 hours.
Funny thing about major snowstorms, though: there’s not much looting in their aftermath.
Including a waterproof case, some right-angle connectors, and a pipe clamp:
M20 in waterproof case – Tour Easy seat
The stack turns out to be about as flexy as one might imagine, definitely a Bad Thing for a bike-mounted camera, and a somewhat more rugged mount seems in order.
A diagram from the M20 manual shows the parts:
SJCAM M20 Overview – Manual pg 5
Some camera dimensions:
40.2 mm wide + 0.5 mm for the Up/Down buttons
21.8 mm thick + 1.0 mm cylindrical front curve + 1.0 mm rear screen
50.0 mm tall + 4.0 mm cylindrical top curve + buttons
21.7 mm OD × 6.0 mm long lens housing, 1.3 mm down from top center
All the edges have neat chamfers or radius rounding on the order of a few millimeters.
Applying the chord equation to the spans inside the rounding:
Front radius: 162.5 mm
Top radius: 42.5 mm
The new batteries survive for a bit over an hour, not quite enough for our usual rides. Rather than conjure a fake battery pack connected to an external 18650 cell with a wire chewed through the case, the least awful way to go may involve a relatively small battery pack (with internal 18650 cells, of course) plugged into the USB port with a right-angle cable and a rigid mount holding both the camera and the pack to the seat frame.
The Fly6 records 1280×720 @ 30 fps, with somewhat high contrast and weird color balance:
Fly6 – Backlit license
It works better with a stationary target in good light:
Fly6 – Stationary license
The M20 records 1920×1080 @60 fps (among many other choices), with reasonable contrast and coloring:
M20 – backlit license
Good lighting and no motion helps it along, too:
M20 – Stationary license
The original frames-grabbed-from-the-video aren’t visibly different from the JPGs you see here.
Collecting all the plates in one montage:
Fly6 vs M20 – License Plates
I enlarged the left pair by 200% and the right pair by 300%, using GIMP’s cubic interpolation, to make them large enough to see with the naked eye. The interpolation algorithm slightly smooths the edges, but the cameras put those weird compression artifacts / blobs in the original images.
The left pair also got auto-brightness adjustments to drag ’em out of the murk.
I saved the montage as a PNG, rather than a JPG, although JPG image compression made no difference.
All in all, the M20 has better image quality than the Fly6, but its 1.5× higher resolution isn’t a slam-dunk win and, IMO, video compression has more effect than image resolution. The Fly6 has no compression controls and I’ve set all the M20 controls to as good as they can be.
Both those license plates sport NYS’s now-obsolete high-contrast blue-on-white color scheme: the current blue-on-gold NYS plates have much lower contrast. In this age of ubiquitous license plate reading and storing, I cannot explain why this was allowed to happen.
The Fly6, now equipped with a high-quality 18650 lithium cell, should have more hours of run time than I can measure this early in the season. Perhaps six hours, with its red blinky LED at full throttle, according to the doc.
The M20 lasted 72 minutes with a freshly charged battery, which means it didn’t quite survive the trip. Performing battery maintenance in the middle of a ride for groceries isn’t appealing; I should conjure an external 18650 battery pack for the thing.
The Smell of Molten Projects in the Morning 