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.
If it used to work, it can work again
Six years on, I just deployed the last of the aluminum spares from the original CNC project:
I swear the cutter gear on the left does not show that rust in person!
This can opener has a slightly larger bolt than the previous ones, so I embiggened the hole with a step drill:
Having run out of aluminum gears, I’ll be forced to make a hob to make a steel gear. Drat!
Being that type of guy, I’m reasonably sure I would not have bought what’s now clearly labeled as an OXO Radial Pepper Grinder for use as a salt mill:
Mary recalls we got it at Target, back when one could go places and buy things, and I vaguely recall contemplating a wall of OXO gadgets. It’s been a while and I neglected to save the packaging for future reference.
Obviously not stainless steel, but not lethal, so we’ll continue abusing it.
After three years, the retainer holding the front bathroom door open against winds blowing through the house on stormy days finally fractured, right at the top of the towel rack where you’d expect it:
I was all set to add reinforcing pins and whatnot, then came to my senses and just made the whole thing a few millimeters larger:
Customer feedback indicates white blends better with the background.
I made a few minor tweaks to the original design, including slightly larger bumps to hold it against the towel bar that, regrettably, put corresponding gouges into the bar. Who knew they used such soft plastic back in the day?
The OpenSCAD source code as a GitHub Gist:
| // Bathroom Door Retainer | |
| // Ed Nisley KE4ZNU – May 2017 | |
| // 2020-07 beef up, particularly at top of bar | |
| Layout = "Show"; // [Show, Build] | |
| //——- | |
| //- Extrusion parameters must match reality! | |
| /* [Hidden] */ | |
| ThreadThick = 0.20; | |
| ThreadWidth = 0.40; | |
| HoleWindage = 0.2; | |
| Protrusion = 0.1; // make holes end cleanly | |
| function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit); | |
| //——- | |
| // Dimensions | |
| /* [Dimensions] */ | |
| TowelBarSide = 20.5; // towel bar across flat side | |
| TowelBarAngle = 45; // rotation of top flat from horizontal | |
| BumpOD = 2.0; // retaining ball | |
| DoorOffset = 14.0; // from towel bar to door | |
| DoorThick = 37.0; | |
| WallThick = 8.0; // minimum wall thickness | |
| PlateThick = 4.0; // … slab | |
| RetainerDepth = 15.0; // thickness of retaining notch | |
| NumSides = 6*4; | |
| CornerRad = WallThick; | |
| BarClipOD = TowelBarSide*sqrt(2) + 2*WallThick; | |
| BarClipRad = BarClipOD/2; | |
| OAH = RetainerDepth + PlateThick; | |
| module LatchPlan() { | |
| union() { | |
| linear_extrude(height=OAH,convexity=4) | |
| difference() { | |
| union() { | |
| circle(d=BarClipOD,$fn=NumSides); | |
| hull() | |
| for (i=[0,1], j=[0,1]) | |
| translate([i*(BarClipRad + DoorOffset + DoorThick + WallThick – CornerRad),j*(BarClipRad – CornerRad)]) | |
| circle(r=CornerRad,$fn=4*4); | |
| } | |
| rotate(TowelBarAngle) // towel bar shape | |
| square(size=TowelBarSide,center=true); | |
| translate([0,-TowelBarSide/sqrt(2)]) // make access slot | |
| rotate(-TowelBarAngle) | |
| square(size=[2*TowelBarSide,TowelBarSide],center=false); | |
| } | |
| for (a=[0:180:360]) | |
| rotate(a + TowelBarAngle) | |
| translate([TowelBarSide/2,0,OAH/2]) | |
| rotate([90,0,45]) | |
| sphere(d=BumpOD,$fn=4*3); | |
| } | |
| } | |
| module Latch() { | |
| difference() { | |
| LatchPlan(); | |
| translate([BarClipRad + DoorOffset,-BarClipRad/2,-Protrusion]) | |
| cube([DoorThick,BarClipOD,RetainerDepth + Protrusion],center=false); | |
| } | |
| } | |
| //——- | |
| // Build it! | |
| if (Layout == "Show") { | |
| Latch(); | |
| } | |
| if (Layout == "Build") { | |
| translate([0,0,OAH]) | |
| rotate([180,0,0]) | |
| Latch(); | |
| } |
Done!
Although the Dell Latitude E7250 allegedly had Bluetooth capability and the Blueman applet tried connecting to my Bluetooth headsets, the connection aways failed and nothing worked. There’s a WLAN module stuck in an M.2 socket inside the laptop providing both WiFi and Bluetooth:
A bit of searching suggested the driver wasn’t loading properly, which became obvious after I knew where to look:
dmesg | grep -i blue
… snippage …
[ 5.678610] Bluetooth: hci0: BCM20702A1 (001.002.014) build 1572
[ 5.678851] bluetooth hci0: Direct firmware load for brcm/BCM20702A1-0a5c-216f.hcd failed with error -2
[ 5.678853] Bluetooth: hci0: BCM: Patch brcm/BCM20702A1-0a5c-216f.hcd not found
[ 10.854607] Bluetooth: RFCOMM TTY layer initialized
[ 10.854613] Bluetooth: RFCOMM socket layer initialized
[ 10.854619] Bluetooth: RFCOMM ver 1.11Without having the proper firmware / patch loaded, the module won’t work, even though the TTY / socket layers know it’s present, which explains why Blueman did everything except actually connect to the headsets.
More searching suggested you must extract the firmware HEX file from the Windows driver. Feeding the Service Tag into the Dell support site, then feeding “Bluetooth” and “Windows 8.1, 64-bit” (preinstalled on the laptop) into the Drivers & Downloads tab gets you the relevant EXE file: Dell Wireless 1550/1560 Wi-Fi and Bluetooth Driver. It turns out to be a self-extracting ZIP file (in Windows, anyway), so unzip it all by yourself:
unzip Network_Driver_5DFVH_WN32_6.30.223.262_A03.EXEThis produces a blizzard of HEX files in the newly created Drivers/production/Windows8.1-x64 directory. Each firmware HEX file is keyed to the USB Product Code identifying the unique USB gadget, found with lsusb:
lsusb
… snippage …
Bus 002 Device 003: ID 0a5c:216f Broadcom Corp. BCM20702A0 Bluetooth
… snippage …The DW1560 apparently has a USB RAM interface, with the specific HEX file identified in the CopyList stanza of the INF file corresponding to that USB Product Code:
grep -i -A 5 ramusb216f.copylist Drivers/production/Windows8.1-x64/bcbtums-win8x64-brcm.inf
[RAMUSB216F.CopyList]
bcbtums.sys
btwampfl.sys
BCM20702A1_001.002.014.1443.1572.hex
… snippage …However, the Linux firmware loader needs a different file format with a different name, mashed together from the HEX file, USB Vendor, and USB Product codes:
hex2hcd -o BCM20702A1-0a5c-216f.hcd BCM20702A1_001.002.014.1443.1572.hexThe converted firmware file goes where the loader expected to find it:
sudo cp BCM20702A1-0a5c-216f.hcd /lib/firmware/brcm/Whereupon next reboot sorted things out:
dmesg | grep -i blue
[ 6.024838] Bluetooth: Core ver 2.22
[ 6.024868] Bluetooth: HCI device and connection manager initialized
[ 6.024872] Bluetooth: HCI socket layer initialized
[ 6.024874] Bluetooth: L2CAP socket layer initialized
[ 6.024881] Bluetooth: SCO socket layer initialized
[ 6.100796] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 6.100800] Bluetooth: BNEP filters: protocol multicast
[ 6.100804] Bluetooth: BNEP socket layer initialized
[ 6.157114] Bluetooth: hci0: BCM: chip id 63
[ 6.158125] Bluetooth: hci0: BCM: features 0x07
[ 6.176119] Bluetooth: hci0: BCM20702A
[ 6.177114] Bluetooth: hci0: BCM20702A1 (001.002.014) build 0000
[ 7.031228] Bluetooth: hci0: BCM20702A1 (001.002.014) build 1572
[ 7.047177] Bluetooth: hci0: DW1560 Bluetooth 4.0 LE
[ 13.141854] Bluetooth: RFCOMM TTY layer initialized
[ 13.141865] Bluetooth: RFCOMM socket layer initialized
[ 13.141872] Bluetooth: RFCOMM ver 1.11The firmware may be in one of the myriad Bluetooth packages not installed by default, so perhaps identifying & installing the proper package would sidestep the hocus-pocus.
Maybe next time?
Now I can wear my Bose Hearphones in Zoom sessions with the E7250, because my Pixel 3a phone heats up almost to the gets-bendy level while thrashing its battery to death.
Just for completeness, here’s what the various soaker hose clamps look like in the garden, as solid models only let you visualize the ideal situation:
This one prevents a puddle in the path to the right:
Bending the hoses around the end of a bed puts them on edge, with this clamp suppressing a shin-soaking spray to the left:
The clamp at the connector closes a leak around the crimped brass fitting, with the other two preventing gouges from direct sprays into the path along the bottom of the picture:
All in all, a definite UI improvement!
As far as I can tell, we have the only soaker hose repairs & spritz stoppers in existence. Hooray for 3D printing!
The SJCAM M20 action camera has been attached to the back of my Tour Easy for the last 16 months:
The Anker 13 A·h USB power pack on the rack provides juice for a week’s worth of rides, letting the M20’s internal battery keep its clock & settings alive between rides. I recently forgot to turn on the USB pack and discovered the camera shut down just after I cleared the end of the driveway.
As you should expect, the battery had swollen so much its pull tab … pulled off … when I tried to extract it:
So, we begin.
Pry off the trim ring around the lens by jamming a small screwdriver in any of the three slots:
Then pry off the entire front panel:
Thereby exposing the battery’s rectangular protrusion and three contacts next to the optical block:
Avoid shorting the brass terminals with, say, a small screwdriver, while shoving the battery out of the camera until you can grab it with your fingers and haul it out the rest of the way:
Yeah, that puppy looks all swoll up:
Remove the all-enclosing label to reveal the bag inside:
Pull the bag out to reveal the protection PCB:
Snip the wires and salvage the case against future need.
I bought the camera with three batteries, all three of which are now similarly swollen. I also got two official SJAM batteries with an official SJAM charger; both of those batteries seem to be in fine shape. I expect the codes on the five bags would reveal two different lots, but I’m not going to sacrifice a nominally good battery to find out.
All three swollen battery bags show the same BEP 782633PL lot code and 1704 date code. I bought everything in January 2018, so those batteries had been sitting on the shelf for the better part of a year. Maybe that’s why they offered a “deal” for two spare batteries along with the camera?
Installing one of the unswollen batteries, reconfiguring the camera’s settings & clock, and giving it a charge from the Anker USB pack put it back in operation.
You can do it by hand, as I used to, or use recoverjpeg:
dmesg | tail
cd /tmp
sudo dcfldd if=/dev/sde1 of=pix.bin bs=1M count=100
recoverjpeg pix.bin
ristretto image00*
Nothing prizewinning, but better than no picture at all:
Note that you start by copying a reasonable chunk of the partition from the Memory Stick / (micro)SD Card first, to prevent a bad situation from getting worse.
Now I can remember the easy way the next time around this block …
The Smell of Molten Projects in the Morning 