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.

Category: PC Tweakage

Remembering which tweaks worked

  • Xubuntu 16.04 LTS Bringup

    Notes on updating my desktop Optiplex 980 from Xubuntu 14.04 LTS to 16.04 LTS, after being unable to compile OpenSCAD, Slic3r, and GNU Radio from source. Blowing three days on reconfiguration & tweakage after a clean install is the price one pays to get rid of a few years of cruft; the old version remains bootable and lootable on another partition, Just In Case.

    Install:

    • nfs-common
    • xfce4-goodies
    • xubuntu-restricted-extras
    • hp2xx
    • xsane, xscanimage
    • kate (which hauls in a big hunk of wayland, alas)
    • digikam
    • chromium-browser
    • devilspie2
    • dropbox (from site)
    • remmina

    Apply:

    The hacks required to ensure NFS mounts happen before signing in seem to be obsolete. Given that systemd now controls everything, I have NFI how to proceed if that’s not the case.

    The Xubuntu load progress display looks like it’s scaled up from 640×480.

    There seems no way to disable on-screen notifications without deep hackery; some of the collateral damage involves the death of the volume control applet in the indicator panel thingy, so I didn’t try very hard.

    The aforementioned volume control now fires up the Pulseaudio control dialog. That display explained why the audio came out of the 980’s crappy internal speaker, but switching it to the HDMI output produced only silence. After blowing away ~/.config/pulse and rebooting that sucker, it’s all good: Linux audio remains a slow-motion train wreck.

    The initial sign-on dialog appears on the portrait monitor, minus rotation, because the dialog box follows the mouse pointer: the initial mouse position sits one pixel beyond the landscape monitor. Blind-type the password, whack Enter, and it’s all good.

    FWIW, I’ve installed the XFCE flavor of Mint Linux on the laptops, but that’s basically Xubuntu with (some of) the ugly sanded off and really doesn’t buy much for somebody who pays no attention to eyecandy.

  • Raspberry Pi Streaming Radio Player: Yet Another Cheap Wireless Keypad

    One might think, just from looking, that this black wireless USB numeric keypad:

    BonyTek Wireless USB Numeric Keypad
    BonyTek Wireless USB Numeric Keypad

    Was identical to the white keypads I already used on the streaming media players:

    Wireless Keypad - colored labels
    Wireless Keypad – colored labels

    One would, of course, be wrong.

    They both claim to be manufactured by “Creative Labs” with a 0x062a vendor ID, but with different model IDs:

    • White = 0x4101 “Wireless Keyboard/Mouse”
    • Black = 0x4182

    Astonishingly, that model ID appears nowhere in Google’s search results, yet it actually works when plugged into my desktop PC.

    The new model ID requires Yet Another Udev Rule in /etc/udev/rules.d/Streamer.rules:

    ATTRS{idVendor}=="062a", ATTRS{idProduct}=="4182", ENV{ID_INPUT_KEYBOARD}=="1", SYMLINK+="input/keypad"

    No big deal by now …

  • Raspberry Pi: Forcing VNC Display Resolution

    You can use VNC with a headless Raspberry Pi, but, absent a display with which to negotiate the screen resolution, X defaults something uselessly small: 720×480. To force a more reasonable resolution, edit /boot/config.txt and set the framebuffer size:

    framebuffer_width=1920
framebuffer_height=1280

    You can use a nonstandard resolutions, as with the 1920×1280 that fits neatly on my 2560×1440 landscape monitor, but getting too weird will surely bring its own reward. When you plug in a display, X will ought to negotiate as usual for the highest resolution the display can handle.

    The System Configuration dialog has a “Resolution” button offering standard resolutions:

    RPi display resolution configuration
    RPi display resolution configuration

    The shiny RPi Pixel UI bakes the RealVNC server directly into whatever handles the startup process these days, rendering all previous recommendations about forcing VNC resolutions inoperative. I found the trick of editing the config file on StackExchange after the usual flailing around.

    Memo to Self: Remmina (the VNC client I use in XFCE on my desktop PC) doesn’t respond well to having the VNC server shut down while it’s connected. Fire up a command prompt, enter this:

    sleep 10 ; sudo reboot

    Then, quick like a bunny, disconnect the VNC session.

  • Kinesis Freestyle2 Keyboard vs. Linux

    My old Microsoft Comfort Curve keyboard having gotten on in years, I picked up a Kinesis Freestyle2 (KB800B for PC) split keyboard:

    Kinesis Freestyle2 - desk layout
    Kinesis Freestyle2 – desk layout

    The little hinged dingus (“Pivot Tether”) between the halves (“Keying Modules”) has two posts that pop into into sockets on the back of the halves and are retained by the two sliding latches. The cord connecting the halves allows 9 inches of separation; I don’t need that much, but more than zero seemed about right.

    Kinesis also sells various staggeringly expensive (IMO) doodads that attach to the back of the keyboard to “tent” the middle upward with varying degrees of refinement. None of the doodads offer to raise the back of the keyboard, which I vastly prefer to the current flat or reverse-tilted recommendations.

    The keyboard & trackballs rest on a homebrew shelf that slides out from where the desk used to have a center drawer, which puts the keyboard slightly above elbow height (heck, slightly above thigh height), whereupon tilting the keyboard puts the keys exactly where they should be. I bandsawed some wood into vaguely triangular sticks, topped them with foam sheets, and tinkered for best tilt. Works for me, anyhow.

    The Compatibility section of the Freestyle2 User Manual describes the “special driverless hot keys”: Most will also work with Linux. Four of them do not work, to the extent that they don’t even send key codes to exv. Some searching suggests this is an intractable problem, for reasons that make no sense to me. Their HID Usage Codes, whatever that might mean:

    Kinesis Freestyle2 - inert key codes
    Kinesis Freestyle2 – inert key codes

    That’s only a minor inconvenience; I prefer a physical calculator and don’t spend much of my life listening to anything through the headphones.

    For whatever it’s worth, the scroll ring on the most recent warranty replacement Kensington Expert “Mouse” (I think it’s the third) has worked flawlessly for years; they seem to have fixed the sudden death syndrome.

  • Epson R380 Printer: Resetting the Waste Ink Counter Again

    The Epson R380 printer never gets turned off, so it rarely has a chance to complain. After a powerdown due to refreshing the UPS batteries, it lit up with the dreaded “Service required. Visit your friendly Epson repair center” message that indicates you should just throw the printer out, because replacing the internal ink absorber mats / draining the internal tank is, mmm, economically infeasible when you pay somebody else to do it.

    Having done this before, though, it’s almost easy…

    • Pop a PC with a Windows partition off the to-be-recycled stack
    • Boot System Rescue CD
    • Back up the partition to a junk hard drive, just for practice
    • Copy the subdirectory of sketchy utilities to the Windows drive
    • Boot Windows (with no network connection)
    • Run sketchy utility to reset the ink counter
    • Boot SRC, restore partition
    • Return hard drive & PC to their respective piles
    • Declare victory and move on

    This time, a sketchy utility that resembled the Official Epson Reset Program actually reset something and the printer started up normally. As before, however, the saved MBR didn’t match the on-disk MBR, suggesting that either I don’t understand how to save / restore the MBR or that something once again meddled with the MBR in between the backup and the restore.

    I’ve emptied the waste ink tank maybe three times since the last reset: plenty of ink down the drain. Fortunately, I loves me some good continuous-flow ink supply action…

    Sheesh & similar remarks.

  • Inspiron Mini 10 as a 3D Printer Controller

    It turns out that the dual-core Intel Atom Inside an old Dell Mini 10 isn’t up to the demands of rendering modern web design; disk I/O speed has nothing to do with the CPU’s (lack of) ability to chew through multiple layers of cruft adorning what used to be straightforward static HTML.

    So, equipped with Linux Mint / XFCE, it’s now found a new purpose in life:

    SnowWhite back in action
    SnowWhite back in action

    In truth, an Atom isn’t quite up to the demands of modern 3D printing, either, at least in terms of processing a huge G-Code file into a layer-by-layer path preview. Fortunately, Pronterface doesn’t generate the preview until you ask for it: arranging the UI to put the preview on a separate tab eliminates that problem.

    The Mini 10 can dribble G-Code into the printer just fine and looks much cuter than the hulking laptop in the background.

  • Opening a Dell Inspiron Mini 10 Case

    I volunteered to update an old Inspiron Mini 10 netbook (or whatever they called the things) with Mint Linux and wanted to see what replacing the dead-slow 5400 rpm hard drive with an SSD would do for the struggling Intel Atom Inside. Dell provides a Service Manual showing how to remove the three screws on the bottom of the case, then gently remove the keyboard (!) to get access to the innards.

    You start by covering the screen with some low-tack plastic film that you’ve been saving for this very purpose, sticking a small screwdriver into the center screw hole, and pushing the keyboard firmly away from the case. This bends the keyboard enough to get your fingernails underneath, after which you can pull / pry it away from the latches on each side.

    The left side of the keyboard (as seen from the normal vantage point) comes out first, after clearing a small latch just over the single left-side USB port:

    Dell Inspiron Mini 10 - left keyboard latch
    Dell Inspiron Mini 10 – left keyboard latch

    The right side pops free from its latch over the HMDI port when you push the keyboard firmly to the left:

    Dell Inspiron Mini 10 - right keyboard latch
    Dell Inspiron Mini 10 – right keyboard latch

    Then release the keyboard’s ribbon cable clamp, pull the cable out, remove the keyboard, remove the single screw holding the hard drive carrier in place, and swap drives in the obvious manner.

    Conclusion: an SSD helps a lot, but Firefox on an Atom CPU remains pretty slow off the starting blocks …