The Smell of Molten Projects in the Morning
Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Electrical & Electronic gadgets
A bit of rummaging produced a desk lamp arm, minus whatever lamp it originally held, ready to hold the second photo lamp, after a bit of epoxy on one locking knob:
The flanged nut will seat on the wrecked part of the knob, with the epoxy holding it in place and somewhat reinforcing the perimeter. I’m not sure this will last forever, but it’ll be a start.
Printing a second cold shoe, though, worked perfectly, and everything fit:
I love it when a plan comes together!
Another attempt at replacing the Wyze camera firmware went much more smoothly, producing a pair of small cameras with better network manners:
That’s a VLC screen capture from the RTSP stream; obviously, I must up my clutter control game.
I formatted a 32 GB MicroSD card with a 512 MB partition, which may not be strictly necessary, copied the MicroSD CFW bootloader (as demo.bin, sheesh), and it installed without drama.
I resized the partition to 32 GB, installed the firmware (per the FAQ) into the root directory, tweaked the configuration files to match my situation, popped it in the camera, plugged the power cable, and It Just Worked™.
Herewith, a checklist of config directory files requiring tweakage:
wpa_supplicant – WiFi SSID and passwordtimezone.conf – America/New_York for usosd.conf – can be tweaked through the Web interfacestaticip.conf – 192.168.1.11x, as you likeresolve.conf – pihole or router IP, as neededdefaultgw.conf – router IPrtspserver.conf – different ports for additional camerasIt would be possible to have the pihole’s DHCP server assign a fixed IP address to each camera, based on its MAC address, but this way the camera knows who it is right from the start and what it’s supposed to be doing.
The router isn’t bright enough to route different port numbers on its Internet side to different LAN IP addresses with the same port address, so each camera must stream from a different port number. I don’t plan many world-available video streams, but a friend does enjoy watching the birds during feeder season.
With the RTSP stream up & running, I flashed the U-Boot bootloader (again, minus drama) and tweaked its uEnv.txt configuration file:
The cameras now produce no objectionable network activity, dramatically down from the Wyze firmware’s desperate attempts to contact various servers, every five minutes, around the clock. I have no way of tracking connections made with direct dotted-quad IP addresses, rather than through the pihole, but … this is a distinct improvement.
Having won an eBay action for a known-dead Sony DSC-F717 at $0.99 (plus $15 shipping, the seller being no fool), I now have a possibly salvageable camera, a Genuine Sony AC supply, and two more NP-FM50 batteries for about the price of any one of the components.
One battery arrived stone-cold dead, suggesting the camera had been put away with the battery installed for a very long time and they died companionably. The camera still charges a (good) battery, even though it doesn’t turn on, and perusing the schematics suggests checking the power switch, because it’s always the switch contacts. That’s for another day, though.
For the record, the battery status:
The red and green traces come from the two batteries I’ve been cycling through the camera since, um, 2003, so they’re getting on in years and correspondingly low in capacity.
The fourth battery (2019 D, the date showing when it arrived, not its manufacturing date) went from “fully charged” to “dead” in about three seconds with a 500 mA load, producing the nearly invisible purple trace dropping straight down along the Y axis.
Sawing the dead battery case around its welded joint at a depth of 0.75 mm, then prying with a small chisel, exposed the contents without histrionics:
Now, there’s a name to conjure with. Turns out Sony sold off its Fukushima battery business a while back, so these must be collectibles. Who knew?
The lower cell is lifeless, the upper cell may still have some capacity. Three pairs of 18500 lithium cells are on their way, in the expectation of rebuilding the weakest packs.
After desoldering the battery tab on the right from the PCB, it occurred to me I needed pictures:
Yeah, that’s a nasty melted spot on the case, due to inept solder-wickage.
Unsoldering the three tabs closest to the case releases the cells + PCB from confinement:
I’m still bemused by battery packs with a microcontroller, even though all lithium packs require serious charge controllers. At least this is an Atmel 8-bitter, rather than 32-bit ARM hotness with, yo, WiFi.
The cells have shaped tabs which will require some gimmicking to reproduce:
Now, if only I could reboot the camera …
Having an ancient flip phone in need of a battery, I ordered a Kyocera TXBAT10133 battery from eBay. Described as “new” (which, according to the Ebay listing, means “New: A brand-new, unused, unopened, undamaged item in its original packaging”), I was somewhat surprised to see this emerging from the box:
It obviously led a rather hard life before being harvested from somebody else’s obsolete flip phone and is definitely not “new”.
Not yet having a deep emotional attachment to the thing, I set it up for a capacity test:
Given a very light 100 mA load, it shows about the same capacity as the original battery in our phone:
Given the precarious contact arrangement, the glitches near the right end aren’t surprising.
The battery label claims a 900 mA·h rating, so both have nearly their nominal capacity at such a reduced load. In actual use, the phone has a low battery after a few hours of power-on time, far less than when it was new.
The seller promises a replacement. For all I know, there are no genuinely “new” batteries available for these phones.
Somewhat to my surprise, Aneng AN8008/AN8009 multimeter PCBS sport what looks like a reasonably accurate current sense resistor on the 10 A input:
The legend says 0.01R and the conductor doesn’t look quite like pure copper:
The indentations look like clamp marks from the bending jig, rather than “calibration” notches made while squeezing the wire with diagonal cutters and watching the resistance on another meter.
One might quibble about the overall soldering quality, but one would also be splitting hairs. I doubt the meter leads could withstand 10 A for more than a few seconds, anyhow.
If you buy enough of something, you can buy pretty nearly anything you want, even cheap precision resistors!
Having recently acquired a pair of photo lights and desirous of eliminating some desktop clutter, I decided this ancient incandescent (!) magnifying desk lamp had outlived its usefulness:
The styrene plastic shell isn’t quite so yellowed in real life, but it’s close.
Stripping off the frippery reveals the tilt stem on the arm:
The photo lights have a tilt-pan mount intended for a camera’s cold (or hot) shoe, so I conjured an adapter from the vasty digital deep:
Printing with a brim improved platform griptivity:
Fortunately, the photo lights aren’t very heavy and shouldn’t apply too much stress to the layers across the joint between the stem and the cold shoe. Enlarging the stem perpendicular to the shoe probably didn’t make much difference, but it was easy enough.
Of course, you (well, I) always forget a detail in the first solid model, so I had to mill recesses around the screw hole to clear the centering bosses in the metal arm plates:
Which let it fit perfectly into the arm:
The grody threads on the upper surface around the end of the slot came from poor bridging across a hexagon, so the new version has a simple and tity flat end. The slot is mostly invisible with the tilt-pan adapter in place, anyway.
There being no need for a quick-disconnect fitting, a 1/4-20 button head screw locks the adapter in place:
I stripped the line cord from inside the arm struts and zip-tied the photo lamp’s wall wart cable to the outside:
And then It Just Works™:
The lens and its retaining clips now live in the Big Box o’ Optical parts, where it may come in handy some day.
The OpenSCAD source code as a GitHub Gist:
| // Photo light mount for desk lamp arm | |
| // Ed Nisley – KE4ZNU | |
| // 2019-03 | |
| /* [Layout Options] */ | |
| Layout = "Build"; // [Show,Build] | |
| Part = "Mount"; // [LampArm,ShoeSocket,Mount] | |
| /* [Extrusion Parameters] */ | |
| ThreadWidth = 0.40; | |
| ThreadThick = 0.25; | |
| HoleWindage = 0.2; | |
| Protrusion = 0.1; | |
| //—– | |
| // Dimensions | |
| /* [Hidden] */ | |
| ID = 0; | |
| OD = 1; | |
| LENGTH = 2; | |
| /* [Dimensions] */ | |
| FrictionDisk = [4.0,16.5,11.0]; // squashed inside desk lamp arm frame | |
| Divots = [4.0,9.5,0.75]; // recesses for frame alignment bumps | |
| ArmLength = 30.0; // attached to disk | |
| ShoeWheelOD = 32.0; // lock wheel on photo lamp | |
| ShoeBase = [18.5,18.5,2.0] + [HoleWindage,HoleWindage,2*ThreadWidth]; // square base on photo lamp gimbal | |
| ShoeStem = [6.3,12.0,1.5]; // top slide clearance, ID = 1/4 inch screw | |
| ShoeBlock = [ShoeWheelOD,ShoeWheelOD,2*(ShoeBase.z + ShoeStem.z)]; // overall shoe block | |
| NumSides = 3*4; | |
| //—– | |
| // Useful routines | |
| function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit); | |
| module PolyCyl(Dia,Height,ForceSides=0,Center=false) { // based on nophead's polyholes | |
| Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2); | |
| FixDia = Dia / cos(180/Sides); | |
| cylinder(r=(FixDia + HoleWindage)/2,h=Height,$fn=Sides,center=Center); | |
| } | |
| //—– | |
| // Various Parts | |
| // Arm captured in disk lamp | |
| module LampArm() { | |
| difference() { | |
| union() { | |
| cylinder(d=FrictionDisk[OD],h=FrictionDisk[LENGTH],$fn=NumSides,center=true); | |
| hull() | |
| for (j=[-1,1]) | |
| translate([0,j*(FrictionDisk[OD]/2 – FrictionDisk[LENGTH]/2),0]) { | |
| rotate([0,90,0]) rotate(180/NumSides) | |
| cylinder(d=FrictionDisk[LENGTH]/cos(180/NumSides),h=ArmLength/2,$fn=NumSides); | |
| translate([ArmLength – FrictionDisk[LENGTH]/2,0,0]) | |
| sphere(d=FrictionDisk[LENGTH],$fn=NumSides); | |
| } | |
| } | |
| rotate(180/6) { | |
| PolyCyl(FrictionDisk[ID],FrictionDisk[LENGTH] + 2*Protrusion,6,Center=true); | |
| for (k=[-1,1]) | |
| translate([0,0,k*(FrictionDisk[LENGTH]/2 – Divots[LENGTH]/2)]) | |
| PolyCyl(Divots[OD],Divots[LENGTH] + Protrusion,6,Center=true); | |
| } | |
| } | |
| } | |
| // Basic hot shoe socket | |
| module ShoeSocket() { | |
| difference() { | |
| union() { | |
| cube(ShoeBlock,center=true); // overall blocky retainer | |
| translate([-ShoeBlock.x/2,0,0]) | |
| cylinder(d=ShoeBlock.x,h=ShoeBlock.z,$fn=NumSides,center=true); | |
| } | |
| translate([0,0,-2*ShoeBlock.z]) // screw hole throughout | |
| rotate(180/6) | |
| PolyCyl(ShoeStem[ID],4*ShoeBlock.z,6); | |
| translate([0,0,ShoeBase.z/2]) // base slot under pillar | |
| cube([ShoeBase.x,ShoeBase.y,ShoeBase.z],center=true); | |
| translate([ShoeBase.x/2,0,ShoeBase.z/2]) // base slot opening | |
| cube([ShoeBase.x,ShoeBase.y,ShoeBase.z],center=true); | |
| translate([ShoeStem[OD]/2,0,ShoeBase.z/2 + ShoeStem[LENGTH]]) // stem slot | |
| cube([2*ShoeStem[OD],ShoeStem[OD],2*ShoeStem[LENGTH]],center=true); | |
| } | |
| } | |
| // Stick parts together | |
| module Mount() { | |
| rotate([90,0,0]) | |
| LampArm(); | |
| translate([ArmLength + ShoeBlock.x/2 – Protrusion,0,0]) | |
| ShoeSocket(); | |
| } | |
| //—– | |
| // Build things | |
| if (Layout == "Build") { | |
| rotate([0,90,0]) | |
| translate([-(ArmLength + ShoeBlock.x),0,0]) | |
| Mount(); | |
| } | |
| if (Layout == "Show") | |
| if (Part == "LampArm") | |
| LampArm(); | |
| else if (Part == "ShoeSocket") | |
| ShoeSocket(); | |
| else if (Part == "Mount") | |
| Mount(); |
The original dimension doodles, made before I removed the stem and discovered the recesses around the screw hole:
With the wrecked 5U4GB safely in the trash, I popped a smaller, somewhat less stately triode from the Big Box o’ Hollow-State Electronics and wired it up with a pair of SK6812 RGBW LEDs:
The tube’s markings have long since vanished, but, at this late date, all that matters is an intact glass envelope!
After two years, the ordinary white foam tape holding the knockoff Arduino Nano lost most of its sticktivity and easily popped off the 3D printed base:
Two layers of 3M outdoor-rated foam tape clear the bottom-side components and, based on current evidence, its stickiness should stick forever more:
The alert reader will notice the mis-soldered 1 kΩ SMT resistor above-and-right of the CH340 USB interface chip. I think those two resistors are the isolators between the 328P microcontroller and the CH340, letting you use the TX and RX lines as ordinary I/O without killing either chip.
Despite the mis-soldering, it evidently passed their QC and works fine. Seeing as how I didn’t notice it until just now, it’ll remain in place until I must open the lamp base for some other reason, which may never happen.
The data output is now on pin A5, to match the rest of the glowing widgetry:
Blobs of hot melt glue affix the SK6812 and wiring to the socket:
The original “plate cap” wiring ran directly through a hole in the hard drive platter, which I embiggened for a 3.5 mm panel-mount headphone jack. The knurled metal plug looms next to this smaller tube, but it looks better (in a techie sense) than the raw hole:
Octal tubes have an opaque Bakelite base, so I devoted some Quality Shop Time™ to the post:
Although I’d made a shell drill for 5U4’s base, this base was so crumbly I simply joysticked the spinning cutter around to knock off the rest of the post:
The shell drill would open the bottom to admit a bit more light. I may do that to see if it makes any visible difference.
I didn’t expect the serrations in the top mica plate to cast interesting patterns around the platter:
Memo to Self: use the shell drill to avoid nicking the evacuation tip!
The Smell of Molten Projects in the Morning 