Dell

Roger Cheng

SATA Optical to 2.5″ Drive Adapter

I dusted off an old Dell Optiplex 960 for use as my TrueNAS replication backup target. The compact chassis had a place for my backup storage 8TB 3.5″ HDD extracted from a failed USB enclosure, which is good. But I also need a separate drive for Ubuntu operating system, and that’s where I ran into problems. There was an empty 3.5″ bay and a SATA data socket available on the motherboard, but the metal mounting bracket was missing, and power supply had no more SATA power plugs.

As an alternative plan, I thought I would repurpose the optical drive’s location. Not just its SATA data and power plugs, but I could also repurpose physical mounting bracket with an optical drive shaped caddy for a 2.5″ SATA drive. (*) It wasn’t a perfect fit but that was my own fault for ordering the wrong size.

Examining the caddy after I opened its package, I saw this oddly bent piece of sheet metal. Comparing against the DVD drive, I don’t think it’s supposed to bend like that. I can’t tell if it was damaged at the factory or during shipping, either way metal was thin and easy to bend back into place.

Also comparing against the DVD drive, I realized I bought the wrong size. It didn’t occur to me to check to see if there were multiple different sizes for laptop DVD drives. I bought a 9.5mm thick caddy (*) when I should have bought something thicker possibly this 12.7mm thick unit.(*) Oh well, I have this one in hand now and I’m going to try to make it work.

To install this caddy in an Optiplex 960 chassis, I need to reuse the sheet metal tray currently attached to the DVD drive.

One side fit without problems, but the other side didn’t fit due to mismatched height. This is my own fault.

There’s a mismatch in width as well, I’m not sure this was my fault. I understand the different form factors to be the same width so this part should have lined up. Oh well, at least it is easier to deal with a ~1mm too narrow adapter because one ~1mm too wide wouldn’t fit at all.

There were slots to take the DVD drive’s faceplate. This is for aesthetics so we don’t leave a gaping hole, the eject button wouldn’t work as it is no longer a DVD drive. Unfortunately, faceplate mounting slots didn’t match up, either. This might also be a function of the wrong height, but I’m skeptical. I ended up using the generic faceplate that came with the caddy.

Forcing everything to fit results in a caddy mounted crookedly.

Which resulted in a crooked facade.

Aesthetically speaking this is unfortunate, I should have bought a taller caddy (*) but functionally this unit works fine. The SSD is securely mounted in the caddy, which is now securely mounted to the chassis. And even more importantly, SATA power and data communication worked just fine, allowing me to install Ubuntu Server 22.04 LTS on an old small SSD inside the caddy. And about that old SSD… freeing it up for use turned out to be its own adventure.

(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Roger Cheng

Dusting Off Dell Optiplex 960 SFF PC

After two years of use, my USB3 external 8TB backup drive stopped responding as an external disk. I took apart its enclosure and extracted a standard 3.5″ hard disk drive which seems OK in perfunctory testing. In order to continue using it for TrueNAS replication backup, I’ll need another enclosure. I briefly contemplated getting an USB3 SATA enclosure that takes 3.5″ drives (*) but I decided to use an entire computer as its enclosure: I have an old Dell Optiplex 960 SFF (small form factor) PC collecting dust and it would be more useful as my TrueNAS replication backup machine.

Dell’s Optiplex line is aimed at corporate customers, which meant it incorporated many design priorities that weren’t worth my money to buy new. But those designs also tend to live well past their first lives, and I have bought refurbished corporate Dells before. I’ve found them to be sturdy well-engineered machines that, on the secondhand market, is worth a small premium over generic refurbished PCs.

There’s nothing garish with exterior appearance of an Optiplex, just the computer equivalent of professional office attire. This particular machine is designed to be a little space-efficient box. Office space costs money and some companies decide compactness is worth paying for. Building such a compact box required using parts with nonstandard form factors. For a hobbyist like me, not being able to replace components with generic standard parts is a downside. For the corporate IT department with a Dell service contract, the ease of diagnosis and servicing is well worth the tradeoff.

This box is just as happy sitting horizontally as vertically, with rubber feet to handle either orientation.

Before it collected dust on my shelf, this computer collected dust on another maker’s shelf. I asked for it sometime around the time I started playing with LinuxCNC. I saw this computer had a built-in parallel port, so I would not need an expansion card. (Or I can add a card for even more control pins.) The previous owner said “Sure, I’m not doing anything with it, take it if you will do cool things with it.” Unfortunately, my LinuxCNC investigation came to a halt due to pandemic lockdown and I lost access to that space. TrueNAS replication target may not be as cool as my original intention for this box, but at least it’s better than collection dust.

Even though the chassis is small, it has a lot of nice design features. The row of “1 2 3 4” across the front are diagnostics LEDs. They light up in various combinations during initial boot-up so, if the computer fails to boot corporate IT tech support can start diagnosing failure before even opening up the box.

Which is great, because opening up the box might be hindered by a big beefy lock keeping the side release lever from sliding.

And if we get past the lock and open the lid, we trip the chassis intrusion detection switch. I’ve seen provision for chassis intrusion detection in my hobbyist-grade motherboards, but I never bothered to add an actual intrusion switch to any of my machines. Or a lock, for that matter.

Once opened I find everything is designed to be worked on without requiring specific tools. This chassis accommodates two half-height expansion cards: One PCI and one PCI-Express. On my PCs, expansion endplates are held by small Philips-head screws. On this PC, endplates are retained by this mechanism.

A push on the blue button releases a clamp for access to these endplates.

Adjacent to those expansion slots is a black plastic cage for 3.5″ Hard drive.

Two blue metal clips release the cage to flip open, allowing access to the hard drive. This drive was intended to be the only storage device hosting operating system plus all data. I plan to install my extracted 8TB backup storage drive in this space, which needs to be a separate drive from the operating system drive, so I need to find another space for a system drive.

Most of the motherboard is visible after I flipped the HDD cage out of the way. I see three SATA sockets. One for the storage HDD, one for the DVD drive, and an empty one I can use for my system drive. Next to those slots is a stick of DDR2 RAM. (I’m quite certain Corsair-branded RAM is not original Dell equipment.) Before I do anything else with this computer, I will need to replace the CR2032 coin cell timekeeping battery.

A push on the blue-stickered sheet metal button released the DVD drive. Judging by scratches, this DVD drive has been removed and reinstalled many times.

Putting the DVD drive aside, I can see a spare 3.5″ drive bay underneath. This was expected because we could see a 3.5″ blank plate in the front of this machine, possibly originally designed for a floppy disk drive. The good news is that this bay is empty and available, the bad news is that a critical piece of hardware is missing: This chassis is designed to have a sheet metal tray for installing a 3.5″ drive, which is not here.

I can probably hack around the missing bracket with something 3D-printed or even just double-sided tape. But even if I could mount a small SSD in here, there are no spare SATA power connector available for it. This is a problem. I contemplated repurposing the DVD drive’s power and data cables for a SSD and found adapters cables for this purpose. (*) But under related items, I found a product I didn’t even know existed: an optical-to-hard drive adapter (*) that doesn’t just handle the power and data connectors, it is also a mechanical fit into the optical drive’s space!

(*) Disclosure: As an Amazon Associate I earn from qualifying purchases.

Roger Cheng

Disable Sleep on a Laptop Acting as Server

I’ve played with different ways to install and run Home Assistant. At the moment my home instance is running as a virtual machine inside KVM hypervisor. The physical machine is a refurbished Dell Latitude E6230 running Ubuntu Desktop 22.04. Even though it will be running as a server, I installed the desktop edition for access to tools like Virtual Machine Manager. But there’s a downside to installing the desktop edition for server use: I did not want battery-saving features like suspend and sleep.

When I chose to use an old laptop like a server, I had thought its built-in battery would be useful in case of power failure. But I hadn’t tested that hypothesis until now. Roughly twenty minutes after I unplugged the laptop, it went to sleep. D’oh! The machine still reported 95% of battery capacity, but I couldn’t use that capacity as backup power.

The Ubuntu “Settings” user interface was disappointingly useless for this purpose, with no obvious ability to disable sleep when on battery power. Generally speaking, the revamped “Settings” of Ubuntu 22 has been cleaned up and now has fewer settings cluttering up all those menus. I could see this as a well-meaning effort to make Ubuntu less intimidating to beginners, but right now it’s annoying because I can’t do what I want. To the web search engines!

Looking for command-line tools to change Ubuntu power saving settings brought me to many pages with outdated information that no longer applied to Ubuntu 22. My path to success started with this forum thread on Linux.org. It pointed to this page on linux-tips.us. It has a lot of ads, but it also had applicable information: systemd targets. The page listed four potentially applicable targets:

  • suspend.target
  • sleep.target
  • hibernate.target
  • hybrid-sleep.target

Using “systemctl status” I could check which of those were triggered when my laptop went to sleep.

$ systemctl status suspend.target
○ suspend.target - Suspend
     Loaded: loaded (/lib/systemd/system/suspend.target; static)
     Active: inactive (dead)
       Docs: man:systemd.special(7)

Jul 21 22:58:32 dellhost systemd[1]: Reached target Suspend.
Jul 21 22:58:32 dellhost systemd[1]: Stopped target Suspend.
$ systemctl status sleep.target
○ sleep.target
     Loaded: masked (Reason: Unit sleep.target is masked.)
     Active: inactive (dead) since Thu 2022-07-21 22:58:32 PDT; 11h ago

Jul 21 22:54:41 dellhost systemd[1]: Reached target Sleep.
Jul 21 22:58:32 dellhost systemd[1]: Stopped target Sleep.
$ systemctl status hibernate.target
○ hibernate.target - System Hibernation
     Loaded: loaded (/lib/systemd/system/hibernate.target; static)
     Active: inactive (dead)
       Docs: man:systemd.special(7)
$ systemctl status hybrid-sleep.target
○ hybrid-sleep.target - Hybrid Suspend+Hibernate
     Loaded: loaded (/lib/systemd/system/hybrid-sleep.target; static)
     Active: inactive (dead)
       Docs: man:systemd.special(7)

Looks like my laptop reached the “Sleep” then “Suspend” targets, so I’ll disable those two.

$ sudo systemctl mask sleep.target
Created symlink /etc/systemd/system/sleep.target → /dev/null.
$ sudo systemctl mask suspend.target
Created symlink /etc/systemd/system/suspend.target → /dev/null.

After they were masked, the laptop was willing to use most of its battery capacity instead of just a tiny sliver. This should be good for several hours, but what happens after that? When the battery is almost empty, I want the computer to go into hibernation instead of dying unpredictably and possibly in a bad state. This is why I left hibernation.target alone, but I wanted to do more for battery health. I didn’t want to drain the battery all the way to near-empty, and this thread on AskUbuntu led me to /etc/UPower/UPower.conf which dictates what battery levels will trigger hibernation. I raised the levels so the battery shouldn’t be drained much past 15%.

# Defaults:
# PercentageLow=20
# PercentageCritical=5
# PercentageAction=2
PercentageLow=25
PercentageCritical=20
PercentageAction=15

The UPower service needs to be restarted to pick up those changes.

$ sudo systemctl restart upower.service

Alas, that did not have the effect I hoped it would. Leaving the cord unplugged, the battery dropped straight past 15% and did not go into hibernation. The percentage dropped faster and faster as it went lower, too. Indication that the battery is not in great shape, or at least mismatched with what its management system thought it should be doing.

$ upower -i /org/freedesktop/UPower/devices/battery_BAT0
  native-path:          BAT0
  vendor:               DP-SDI56
  model:                DELL YJNKK18
  serial:               1
  power supply:         yes
  updated:              Fri 22 Jul 2022 03:31:00 PM PDT (9 seconds ago)
  has history:          yes
  has statistics:       yes
  battery
    present:             yes
    rechargeable:        yes
    state:               discharging
    warning-level:       action
    energy:              3.2079 Wh
    energy-empty:        0 Wh
    energy-full:         59.607 Wh
    energy-full-design:  57.72 Wh
    energy-rate:         10.1565 W
    voltage:             9.826 V
    charge-cycles:       N/A
    time to empty:       19.0 minutes
    percentage:          5%
    capacity:            100%
    technology:          lithium-ion
    icon-name:          'battery-caution-symbolic'

I kept it unplugged until it dropped to 2%, at which point the default PercentageAction behavior of PowerOff should have occurred. It did not, so I gave up on this round of testing and plugged the laptop back into its power cord. I’ll have to come back later to figure out why this didn’t work but, hey, at least this old thing was able to run 5 hours and 15 minutes on battery.

And finally: this laptop will be left plugged in most of the time, so it would be nice to limit charging to no more than 80% of capacity to reduce battery wear. I’m OK with 20% reduction in battery runtime. I’m mostly concerned about brief blinks of power of a few minutes. A power failure of 4 hours instead of 5 makes little difference. I have seen “battery charge limit” as an option in the BIOS settings of my newer Dell laptops, but not this old laptop. And unfortunately, it does not appear possible to accomplish this strictly in Ubuntu software without hardware support. That thread did describe an intriguing option, however: dig into the cable to pull out Dell power supply communication wire and hook it up to a switch. When that wire is connected, everything should work as it does today. But when disconnected, some Dell laptops will run on AC power but not charge its battery. I could rig up some sort of external hardware to keep battery level around 75-80%. That would also be a project for another day.

Roger Cheng

Home Assistant OS in KVM Hypervisor

I encountered some problems running Home Assistant Operating System (HAOS) as a virtual machine on a TrueNAS CORE server, which is based on FreeBSD and its bhyve hypervisor. I wanted to solve these problems and, given my good experience with Home Assistant, I was willing to give it dedicated hardware. A lot of people use a Raspberry Pi, but in these times of hardware scarcity a Raspberry Pi is rarer and more valuable than an old laptop. I pulled out a refurbished Dell Latitude E6230 I had originally intended to use as robot brain. Now it shall be my Home Assistant server, which is a robot brain of sorts. This laptop’s Core i5-3320M CPU launched ten years ago, but as a x86_64 capable CPU designed for power-saving laptop usage, it should suit Home Assistant well.

Using Ubuntu KVM Because Direct Installation Failed Boot

I was willing to run HAOS directly on the machine, but the UEFI boot process failed for reasons I can’t decipher. I couldn’t even copy down an error message due to scrambled text on screen. HAOS 8.0 moved to a new boot procedure as per its release announcement, and the comments thread on that page had lots of users reporting boot problems. [UPDATE: A few days later, HAOS 8.1 was released with several boot fixes.] Undeterred, I tried a different tack: install Ubuntu Desktop 22.04 LTS and run HAOS as a virtual machine under KVM Hypervisor. This is the hypervisor used by the Linux-based TrueNAS SCALE, to which I might migrate in the future. Whether it works with HAOS would be an important data point in that decision.

Even though I expect this computer to run as an unattended server most of the time, I installed Ubuntu Desktop instead of Ubuntu Server for two reasons:

  1. Ubuntu Server has no knowledge of laptop components, so I’d be stuck with default hardware behavior that are problematic. First is that the screen will always stay on, which wastes power. Second is that closing the lid will put the machine to sleep, which defeats the point of a server. With Ubuntu Desktop I’ve found how to solve both problems: edit /etc/systemd/logind.conf and change lid switch behavior to lock, which turns off the screen but leaves the computer running. I don’t know how to do this with Ubuntu Server or Home Assistant OS direct installation.
  2. KVM Hypervisor is a huge piece of software with many settings. Given enough time I’m sure I could learn all of the command line tools I need to get things up and running, but I have a faster option with Ubuntu Desktop: Use Virtual Machine Manager to help me make sense of KVM.

KVM Network Bridge

Home Assistant instructions for installing HAOS as a KVM virtual machine was fairly straightforward except for lack of details on how to set up a network bridge. This is required so HAOS is a peer on my home network, capable of communicating with ESPHome devices. (Equivalent to the network_mode: host option when running Home Assistant Docker container.) HAOS instruction page merely says “Select your bridge” so I had to search elsewhere for details.

A promising search hit was How to use bridged networking with libvirt and KVM on linuxconfig.org. It gave a lot of good background information, but I didn’t care for the actual procedure due to this excerpt: “Notice that you can’t use your main ethernet interface […] we will use an additional interface […] provided by an ethernet to usb adapter attached to my machine.” I don’t want to add another Ethernet adapter to my machine. I know network bridging is possible on the existing adapter, because Docker does it with network_mode:host.

My next stop was Configuring Guest Networking page of KVM documentation. It offered several options corresponding to different scenarios, helping me confirm I wanted “Public Bridge”. This page had a few Linux distribution-specific scripts, including one for Debian. Unfortunately, it wanted me to edit a file /etc/network/interfaces which doesn’t exist on Ubuntu 22.04. Fortunately, that page gave me enough relevant keywords for me to find Network Configuration page of Ubuntu documentation which has a section “Bridging” pointing me to /etc/netplan. I had to change their example to match Ethernet hardware names on my computer, but once done I had a public network bridge upon my existing network adapter.

USB Device Redirection

Even though I’m still running HAOS under a virtual machine hypervisor, ESPHome could access USB hardware thanks to KVM device redirection.

First I plug in my ESP32 development board. Then, I open the Home Assistant virtual machine instance and select “Redirect USB device” under “Virtual Machine” menu.

That will bring up a list of plugged-in USB devices, where I could select the USB to UART bridge device on my ESP32 development board. Once selected, the ESPHome add-on running within this instance of HAOS could see the ESP32 board and flash its firmware via USB. This process is not as direct as it would have been for HAOS running directly on the computer, but it’s far better than what I had to do before.

At the moment, surfacing KVM capability for USB device redirection is not available on TrueNAS SCALE but it is a requested feature. Now that I see the feature working, it has become a must-have for me. Until this is done, I probably won’t bother migrating my TrueNAS server from CORE (FreeBSD/bhyve) to SCALE (Linux/KVM) because I want this feature when I consolidate HAOS back onto my TrueNAS hardware. (And probably send this Dell Latitude E6230 back into the storage closet.)

Start on Boot

And finally, I had to tell KVM to launch Home Assistant automatically upon boot. By checking “Start virtual machine on host boot up” under “Boot Options” setting.

In time I expect that I’ll learn the KVM command lines to accomplish what I’m doing today with Virtual Machine Manager, but today I’m glad VMM helps me get everything up and running quickly.

[UPDATE: virsh autostart is the command line tool to launch a virtual machine upon system startup. Haven’t yet figured out command line procedure for USB redirection.]

Roger Cheng

Dell XPS M1330 LED Backlight

My detour into laundry machine repair pushed back my LED backlight adventures for a bit, but I’m back on the topic now armed with my new dedicated backlight tester. The next backlight I shall attempt to salvage came from a Dell XPS M1330. This particular Dell product line offered an optional NVIDIA GPU packed into its lightweight chassis. Some engineering tradeoffs had to be made and history has deemed those tradeoffs to be poor as these laptops had a short life expectancy. In the absence of an official story from Dell, the internet consensus is that heat management was insufficient and these laptops cooked themselves after a few years. I was given one such failed unit which I tore down some years ago. I kept its screen and the laptop’s metal lid in case I wanted a rigid metal framework to go with the screen.

The display module itself was a Toshiba LTD133EWDD which had a native resolution of 1280×800 pixels. Not terribly interesting in today’s 1080p world. Certainly not enough motivation for me to buy an adapter to turn it into an external monitor, and hence a good candidate for backlight extraction.

Unlike the previous LCD modules I’ve taken apart, this one doesn’t cover its integrated control board in opaque black tape. Clear plastic is used instead, and I could immediately pick out the characteristic connection to the rest of the display. At the bottom are two of those high density data connections for the LCD pixel array, and towards the right is an 8-conductor connector for the LED backlight. The IC in closest proximity is my candidate for LED backlight controller.

Despite being clear plastic, it was still a little difficult to read the fine print on that chip. But after the plastic was removed I could clearly read “TOKO 61224 A33X” which failed to return any relevant results in a web search. [UPDATE: Randy has better search Kung Fu than I do, and found a datasheet.] Absent documentation I’m not optimistic I could drive the chip as I could a Texas Instruments TPS 61187. So I’ll probably end up trying to power the LEDs in the backlight directly.

Roger Cheng

ESA ISS Tracker on Dell Latitude X1

My failed effort at an ISS Tracker web kiosk reminded me of my previous failure trying to get Ubuntu Core web kiosk up and running on old hardware. That computer, a Dell Latitude X1, was also very sluggish running modern Ubuntu Mate interactively when I had tried it. I was curious how it would compare with the HP Mini.

The HP Mini has the advantage of age: it is roughly ten years old, whereas the X1 is around fifteen years old. When it comes to computers, an age difference of five years is a huge gulf spanning multiple hardware generations. However, the X1 launched as a top of the line premium machine for people who were willing to pay for a thin and light machine. Hence it was designed under very different criteria than the HP Mini despite similarity in form factor.

As one example: the HP Mini housed a commodity 2.5″ laptop hard drive, but the Dell Latitude X1 used a much smaller form factor hard drive that I have not seen before or since. Given its smaller market and lower volume, I think it is fair to assume the smaller hard drive comes at a significant price premium in exchange for reduction of a few cubic centimeters in volume and grams of weight.

Installing Ubuntu Mate 18.04 on the X1, I confirmed it is still quite sluggish by modern standards. However, this is a comparison test and the Dell X1 surprised me by feeling more responsive than the five years younger HP Mini. Given that they both use spinning platter hard drives and had 1GB of RAM, I thought the difference is probably due to their CPU. The Latitude X1 had an ULV (ultra low voltage) Pentium M 744 processor, which was a premium product showcasing the most processing power Intel can deliver while sipping gently on battery power. In comparison the HP Mini had an Atom processor, an entry-level product optimized for cost. Looking at their spec sheet comparison shows how closely an entry level CPU matches up to a premium CPU from five years earlier, but the Atom had only one quarter of the CPU cache and I think that was a decisive difference.

Despite its constrained cache, the Atom had two cores and thermal design power (TDP) of just 2.5W. In contrast the Pentium M 733 ULV had only a single core and TDP of 5W. Twice the cores, half the electrical power, the younger CPU far more power efficient. And it’s not just the CPU, either, it’s the whole machine. Whereas the HP Mini 110 only needed 7.5W to display ESA ISS Tracker, the Latitude X1 reports drawing more than double that. A little over 17W, according to upower. An aged battery, which has degraded to 43% of its original capacity, could only support that for about 40 minutes.

Device: /org/freedesktop/UPower/devices/battery_BAT0
native-path: BAT0
vendor: Sanyo
model: DELL T61376
serial: 161
power supply: yes
updated: Thu 23 Apr 2020 06:19:06 PM PDT (69 seconds ago)
has history: yes
has statistics: yes
battery
present: yes
rechargeable: yes
state: discharging
warning-level: none
energy: 11.4663 Wh
energy-empty: 0 Wh
energy-full: 11.4663 Wh
energy-full-design: 26.64 Wh
energy-rate: 17.2605 W
voltage: 12.474 V
time to empty: 39.9 minutes
percentage: 100%
capacity: 43.0417%
technology: lithium-ion
icon-name: 'battery-full-symbolic'
History (rate):
1587691145 17.261 discharging

Putting a computer to work showing the ESA tracker is only using its display. It doesn’t involve the keyboard. Such information consumption tasks are performed just as well by touchscreen devices, and I have a few to try. Starting with an Amazon Kindle Fire HD 7.

Roger Cheng

Dell Latitude E6230: Working Too Well To Be Dismembered, NUCC to the Rescue

The previous few blog posts about my refurbished Dell Latitude E6230 was written several months ago and had sat waiting for a long-term verdict. After several months of use I’m now comfortable proclaiming it to be a very nice little laptop. Small, lightweight, good battery life, and decently high performance when I need it. (At the cost of battery life when doing so, naturally.)

The heart of this machine is a third generation Intel Core i5, which covers the majority of computing needs I’ve had while away from my desk. From the basics like 64-bit software capability to its ability to speed itself up to tackle bigger workloads. When working away from a wall plug and running on battery, the E6230 slows only minimally. Unlike my much newer Inspiron 7577 which slows drastically while on battery to the extent that it occasionally felt slower than the E6230. I can run my 7577 for perhaps two to four hours on battery, never far from a reminder of its limited on-battery performance. Whereas I can run the E6230 for around four to six hours on battery, without feeling constrained by reduced performance.

The E6230 has several other features I felt would be good for a robot brain. Top of the list is an Ethernet port for reliable communication in crowded RF environments. Several “SuperSpeed” USB 3 ports are useful for interfacing with hardware. And when I want more screen real estate than the built-in screen can offer, I have my choice of VGA or HDMI video output.

That built-in screen, with its minimal 1366×768 resolution, is about the only thing standing between this machine and greatness. Originally I did not care, because I had planned to tear the case apart and embed just the motherboard in a robot. But this laptop is working too darned well to be subjected to that fate! For the near future I plan to continue using the E6230 as a small laptop for computing on-the-go, and kept my eyes open for other old laptops as robot brain candidates.

An opportunity arose at Sparklecon 2020, when I mentioned this project idea to NUCC. They had a cabinet of laptops retired for one reason or another. I was asked: “What do you need?” and I said the ideal candidate would be a laptop with a broken screen and/or damaged keyboard, and have at least a Core i3 processor.

We didn’t find my ideal candidate, but I did get to bring home three machines for investigation. Each representing a single criteria: one with a busted screen, one with a busted keyboard, and one with a Core i3 processor.

Close enough! And now it’s time for me to get to work on a research project: determine what condition these machines are in, and how they can be best put to use.

Roger Cheng

Dell Latitude E6230: Blank ExpressCard Placeholder Is Also A Ruler

I found a fun little design while looking over the refurbished laptop I had bought. It was a Dell Latitude E6230, which had an ExpressCard slot. I’ve never used a laptop in a way that required add-on hardware. No PCMCIA, no ExpressCard, etc. Few of my laptops even had provisions for an expansion slot. But I remembered one of them — an old Dell XPS M1330 — included a little bit of creativity. Rather than the typical blank piece of plastic placeholder, the expansion slot held an infrared remote control with simple media buttons like “Play”, “Pause”, etc. This lets people use the little laptop as a media player where they can sit back away from the keyboard and still be able to control playback.

This laptop is from Dell’s business-oriented Latitude line, so it would not be keeping with product position to have such entertainment-oriented accessories. But I was curious if it had more than just a blank piece of plastic placeholder. So even though I had no ExpressCard to install, I popped out the blank to take a look. I was happy to see that someone put some thought into the design: the blank plate is a small ruler with both inch and millimeter measurements.

This feature cost them very little to implement, and it would never be the make-or-break deciding factor when choosing the laptop, but it was a fun touch.

Roger Cheng

Dell Latitude E6230: Soft Touch Plastic Did Not Age Well

When I looked over the exterior of my refurbished Dell Latitude E6230 laptop, I noticed  some common touch parts of the wrist rest and touch pad had been covered with stickers. They were very well done on my example. It took me a while to realized they were even there. In use, they were not bothersome.

Initially I thought they were there to cover up signs of wear and tear on this refurbished machine, but I’ve realized there’s an additional and possibly more important reason for the sticker: The plastic material for the wrist rest has degraded.

Usually when plastic degrades it hardens or discolors, but for certain types of plastic, the breakdown results in a sticky surface that is unpleasant to touch. I usually see this in the flexible plastic shroud for old cables and not in rigid installations like a keyboard wrist rest. I assume these machines were originally built with some type of soft touch plastic which degraded in this very unpleasant manner.

I wonder what the production story behind this laptop is. I can think of a few possibilities right away and I’m sure there are more:

  1. Dell did not perform long term testing on this material and didn’t know it would degrade this way.
  2. Dell performed testing, but the methodology for accelerated aging didn’t trigger this behavior, so it didn’t show up in the tests.
  3. Dell was aware of this behavior, believed it would not occur until well after warranty period, and thus not their problem.

The expensive way to solve this problem would be to re-cast the plastic wrist rest in a different material and replace the part. Covering just the important surfaces with stickers is an ingeniously inexpensive workaround. Once the stickers were installed, I wouldn’t have to touch the unpleasant surfaces in normal use. However, there are still some sections exposed around the keyboard, and the sticky material is now a dust magnet.

It is a flaw in this little capable machine, but one I can tolerate thanks to the stickers. It made the laptop cheap to buy refurbished, and I’ll be less reluctant to take the computer apart and embed it in a robot, which is one of the long term plans for this machine.

Roger Cheng

Dell Latitude E6230: Hardware Internals

I picked up a Core i5-powered Dell Latitude E6230. It was a refurbished item at Fry’s Electronics, on sale for $149, and that was too tempting of a bargain to pass up. There were two major downsides to the machine: a low resolution 1366×768 display that I couldn’t do anything about, and a spinning magnetic platter hard drive that I intend to upgrade.

As is typical of Dell, a service manual is available online and I consulted it before purchasing to verify this chassis use standard laptop form factor SATA drive for storage. (Unlike the last compact Dell I bought.) Once I got it home, it was easy to work on this machine designed to be easily serviceable as is most Latitudes. A single screw releases the back cover, and the HDD was held down by two more screws. With only three screws and two plastic modules to deal with, this SSD upgrade needed less than five minutes to complete.

But since I had it open anyway, I spent some more time looking around inside to see signs of this laptop’s prior life.

Dell Latitude E6230 interior debris

There were a few curious pieces of debris inside. A piece of tape that presumably held down a segment of wire has come loose, and the adhesive is not sticky. This is consistent with aged tape. There was also a loose piece of clear plastic next to the tape. I removed both.

The CPU fan had an fine layer of insignificant dust clinging to its surface. I would have expected an old laptop to have picked up more dirt than this. Either the buildup has been cleaned up (and the cleaner ignored the tape and clear plastic) or more likely this laptop spent most of its time in an office HVAC environment with well maintained dust filtration.

The HDD that I removed was advertised to have a copy of Windows 10. But where is the license? Computers of this vintage may have their Windows license embedded in hardware. Though this is less likely for business line machines, as some businesses have their own site license for Windows. I installed Windows 10 on the SSD and checked its licensing state: not activated. The Windows 10 license is on that HDD and not in hardware. That’s fine, I intended to run Ubuntu on this one anyway, so I installed Ubuntu 18.04 over the non-activated Windows 10.

Once Ubuntu 18.04 was up and running, this machine proved quite capable. All features appear to be usable under Ubuntu and it is easily faster than my Inspiron 11 3180 across the board. It is a bit heavier, but much of that is the extended battery and might be worth the tradeoff.

Overall, a very good deal for $149 and my new ROS robot brain candidate.

Roger Cheng

Dell Latitude E6230: First Impressions

Dell’s business oriented Latitude line command a price premium over their consumer grade Inspiron offerings, some of that money actually does go towards features for long term durability of those machines. A Latitude X1 I bought over a decade ago is still running. None of the Inspiron I’ve purchased has lasted nearly as long.

But despite their longevity, many businesses retire their computers on a regular schedule independent of actual condition. Once retired they go into a secondary market, a great opportunity for bargain hunters. Recently a batch of refurbished Dell Latitude E6230 were on sale for $149 at Fry’s Electronics and that was too good of a deal to pass up. For comparison, a new eighth-generation Core i5 processor is roughly $200 at retail, and that’s just the processor. This refurbished machine has an old but still capable third-generation Core i5 processor at its heart, and an entire computer around it including storage, memory, display, and battery. The price/performance ratio here trounces every other candidate for a ROS robot brain. Even the low cost leader, the Raspberry Pi, would have a hard time matching this price point after adding storage, display, battery, etc. In terms of computing power, an old Core i5 will have no problem leaving a Raspberry Pi in the dust.

I’ve had good luck with refurbished Dell computers so far. (Including that teenager Latitude X1.) So I thought I would pick up one of these units to see what I had to trade off for this screaming bargain. The answer is: not a whole lot.

The machine is very definitely used. There are visible wear and tear on exterior, but all purely cosmetic: discoloration of emblems, rubbed off paint, things along those lines.

Dell Latitude E6230 palm rest sticker

A typical sign of wear on an old laptop is the palm rest. I saw no wear at all in the palm rest area and was impressed until I realized what they had done: They’ve added a sticker over the palm rest to give it a new surface. The curled-up visible edge of this sheet gave the trick away. The surface of the touchpad, another frequent sign of age, also received the sticker treatment.

According to the documentation in its box, this laptop’s refurbishment was performed by a company called Advanced Skyline Technology, Ltd. Side effect of a non-Dell refurbished computer are a few tradeoffs for cost. The AC power adapter is not a genuine Dell item, neither is the battery. However, the battery has the larger size of an extended runtime battery. If it actually offers longer runtime that would be a pleasant surprise.

This machine came with a spinning platter hard disk, which I was not interested in using so the first project with this machine is to open it up, look around its insides, and upgrade it to a solid state drive.

Roger Cheng

Ubuntu Core 18 Web Kiosk Experiment on Dell Inspiron 11 3180

While experimenting with Ubuntu Core 18 on a 14-year old Dell Latitude X1, I ran into problems and wanted to verify it was a hardware support issue and not a mistake on my part. So I brought my much younger Inspiron 11 (3180) up on Ubuntu Core 18 as well. It verified the issue was indeed hardware support and not my mistake, hampering functionality on the Latitude X1.

After I got my answer, I thought since I’ve already got this Inspiron 11 up and running, I might as well continue experimenting on it. I proceeded to follow through the rest of the steps in the tutorial for setting up a web kiosk on Ubuntu Core. Since this machine had recent hardware, I encountered no hardware issues and got a dedicated web kiosk machine up and running.

Browsing a few web sites, basic browser functionality seem to be present. The first missing functionality I noticed was a lack of sound. A little poking confirmed that Linux audio system ALSA is not installed as part of Ubuntu Core. If someone wants sound on their Ubuntu Core machine, they’ll have to install it. This is fits with my expectation for a bare minimum “Core” OS.

Another feature I noticed is the lack of persistent state. As far as I can tell, everything is ephemeral and lost upon reset. No cookies are preserved across sessions, and it appears the cache is flushed as well. Whether this is a bug or a feature depends on application. It would be desirable for public use web terminal where we really want to wipe everything and start over for every new user.

And it isn’t intended to be a general use web browser, anyway. The cursor can be hidden and so can the navigation bar. I enabled the navigation bar expecting a normal browser tool bar, but it is actually a very minimalist bar with a few buttons like back and refresh. There is no URL input field, as appropriate for a kiosk dedicated to serving specific pages.

Sometimes this is exactly what I would need making Ubuntu Core an ideal bare-minimum OS for an Intel-based machine. But in this day and age, those aren’t our only options. Projects along these lines are also commonly built with a Raspberry Pi. How well does Ubuntu Core work on a Raspberry Pi, compared to Raspberry Pi’s standard Raspbian OS?

Roger Cheng

Dell Latitude X1 Running Ubuntu Core 18: No Graphics But CH341 USB Serial Works

It was a pleasant surprise to see the Ubuntu Core 18 up and running on a 14-year old Dell Latitude X1, even more pleasant to see it is lightweight enough to be speedy and responsive on such old and slow hardware. But given its age, I knew not to expect everything to work on the stock i386 image. There’s no way they can package a comprehensive set of device drivers on such a compact package. I speculate it was not the intent, either. Ubuntu Core is targeted to embedded projects where it is typical to generate an OS image custom tailored to the specific hardware. So the fact it mostly works out of the box is a tremendous bonus, and the missing hardware support is not a bug.

That said, I’m not terribly interested in generating the custom device tree (or whatever mechanism Ubuntu Core uses) to utilize all peripherals on this Latitude X1. I’m more interested in working with what I already have on hand. During initial configuration I already learned that the wireless module did not work properly. What works, and what doesn’t?

Again I’m not interested in an exhaustive list, I just wanted to find enough to enable interesting projects. Getting this far meant text output and keyboard input functions in addition to wired networking. The next thing to try is to activate the graphics subsystem and mouse input. Looking on Ubuntu’s tutorial web site, I found the web kiosk example which would test hardware necessary to offer a useful set of web-related functionality.

Following the tutorial steps, I could get the machine to switch display modes, but it never got as far as showing a web browser, just a few lines I didn’t understand. At this point I wasn’t sure if I followed the procedures correctly or if the hardware failed, so I duplicated the steps with Ubuntu Core 18 running on my modern Dell Inspiron 11 (3180) laptop. I saw a web browser, so the procedures were correct and the hardware is at fault. Oh well.

Comparing what’s on screen after starting mir-kiosk on both machines, I see the gibberish lines on the X1 actually resemble the mouse arrow but distorted and scattered across interleaved lines. Lending to the hypothesis that video support on stock Ubuntu Core 18 i386 image needs some tweaks before it can support the video hardware on board a Latitude X1. The fact some lines showed up tells me it’s close, but I’m choosing not to invest the time to make it work.

The next idea is to test USB serial communications. I plugged in an Arduino Nano knockoff with the CH341 USB-serial chip and ran dmesg to learn the device was picked up, understood, and assigned a ttyUSB device path. This particular Arduino was already flashed with a sketch that sent data through the serial port, and as a crude test I used cat /dev/ttyUSB0 to see if anything comes up: it did! This is wonderful news. The Latitude X1 can act as high-level processor counterpart to a lower level controller communicating over USB serial opening up project possibilities. I’ll have to think on that for a while.

Roger Cheng

Dell Latitude X1 Now Running Ubuntu Core 18

About two years ago, an old friend was returned to me: a 2005 vintage Dell Latitude X1. It struggled to run desktop software of 2017 but speed wasn’t the point – the impressive part was that it could run software of 2017 at all. It was never a speed demon even when new, as it sacrificed raw performance for its thin and light (for its day) construction. Over the past two years, I would occasionally dust it off just to see it still running, but as software got more complex it has struggled more and more to act as a modern personal computer.

When an up-to-date Ubuntu 16 LTS desktop edition takes over 10 minutes to boot to the login screen, I had to concede it’s well past time to stop trying to run it as a desktop computer. I hate to give up on this oddball hobby to keep an old machine running modern up to date operating systems, but an interesting idea came up to keep things going: How about running a lighter-weight text-based operating system?

The overburdened desktop Ubuntu was erased to make room for Ubuntu 16.04.6 server. This is a much lighter-weight operating system. As one point of measure, it now takes only about 55 seconds from pressing the power button to a text login prompt. This is much more tolerable than >10 minutes to boot to a graphical login screen.

After I logged in, it gave me a notification that Ubuntu 18 server is available for upgrade. I’ve noticed that my desktop Ubuntu took longer to boot after upgrading from 16 to 18, and I was curious if the text-mode server edition would reflect the same. Since I had no data on this machine anyway, I upgraded to obtain that data point.

The verdict is yes, Ubuntu 18 server takes longer to boot as well. Power button to login prompt now takes 96 seconds, almost double the time for ubuntu 16 server. Actually more than double, considering some portion of that time was hardware initialization and GRUB boot selection timeout before the operating system even started loading.

That was disappointing, but there is an even more interesting experiment: What if, instead of treating this old computer as a server, I treat it as an embedded device? After all, its ~1 GHz CPU and ~1 GB RAM is roughly on par with a Raspberry Pi, and its ~30GB HDD is in the ballpark of microSD cards used in a Pi.

This is the new Ubuntu Core option for bare-bones installations, targeting IoT and other embedded projects. There is an i386 image already available to be installed on the hard drive of this 14-year old Dell laptop. Since Ubuntu Core targets connected devices, I needed a network adapter for initial setup. It looks like the Latitude X1’s WiFi adapter is not supported, but fortunately its wired Ethernet port worked.

Once up and running, I timed its boot time from power switch to login prompt: 35 seconds. Subtracting non-OS overhead, booting Ubuntu 18 Core takes almost half the time of Ubuntu 16 Server, or approaching one quarter of Ubuntu 18 Server. Very nice.

Ubuntu 18 Core makes this old laptop interesting again. Here is a device offering computing power in the ballpark of a Raspberry Pi, plus a display, keyboard, and mouse. (There’s a battery, too, but its degraded capacity barely counts.) It is far too slow to be a general desktop machine, but now it is potentially a viable platform for an embedded device project.

The story of this old workhorse is not yet over…

Roger Cheng

Dell XPS M1330 Battery Pack Teardown

We had an earlier success tearing down a Dell laptop battery pack, where the six salvaged cells still have 70% of original capacity after ten years of service. However, that was from a laptop that could still boot and run from its battery pack. This XPS M1330 battery pack is in far worse shape. How much worse, we were about to find out.

The first critical detail was realizing the battery pack was not the original Dell battery pack. It is an aftermarket type of unknown manufacture. The earlier battery pack tear down yielded Samsung cells, we’re probably not going to get anything nearly as nice this time around.

Once the case was cracked open the suspicion was confirmed: These appear to be generic 18650-sized lithium cells with no manufacturer branding. The nine cells of the battery pack were divided into three modules in series, each module had three cells wired in parallel. The module in the worst shape exhibited severe corrosion and had no voltage across their terminals.

 

The other two modules were in slightly better shape, but they have self-discharged down to approximately 1 volt DC, well under the recommended voltage range. A web search found some details on what happens to overly discharged lithium cells. In short: the chemistry inside the cell starts dissolving itself. If recharged, the dissolved metals may reform in inconvenient ways. Trying to use these cells has three potential outcomes:

  1. Best case: The metals dissolved into the electrolyte will hamper chemical reaction, resulting in reduced capacity.
  2. Medium case: The dissolved metals will reform in a way that damages the cell, causing it to fail as an open-circuit. (As if no battery was present.)
  3. Worst case: The dissolved metals will reform in a way that damages the cell, but causing it to fail as a closed circuit. Short-circuiting the internals will release a lot of energy very quickly, resulting in high-pressure venting and/or fire.

The corroded cells that have discharged down to zero volts have the highest risk and will be discarded. The remaining cells will be slowly (and carefully) charged back up to gauge their behavior.

Roger Cheng

Dell XPS M1330 Power Port Salvaged Using Desoldering Tool

Recently a dead Dell XPS M1330 came across the workbench. The battery was dead and the machine fails to boot. After some effort at reviving the machine, it was declared hopeless and salvage operations began. Today’s effort focuses on the motherboard port for the AC power adapter.

Dell Octagonal PowerThe power plug on this Dell different from the typical Dell laptop AC adapter: octagonal in shape rather than round. The shape meant it could not be used on other Dell laptops designed for the round plug. However, the dimensions of the octagon are such that an AC power adapter with the typical round Dell plug fits and could be used to charge the laptop. So while the laptop could be charged with any existing Dell-compatible AC adapter, the AC adapter that came with this machine is specific to this Dell.

Once the XPS M1330 died, its octagonal plug power adapter is not useful for other Dell laptops. It still functions as a power supply transforming household AC to ~19V DC so it might be useful for future projects. To preserve this possibility, the octagonal power port will be recovered from the system board.

The solder used in Dell assembly was possibly one of the lead-free types and is definitely reluctant to melt and flow. Trying to desolder the power port using hand tools (desoldering wick and hand suction pump) had no luck. So this project was chosen as a practice run of using a dedicated desoldering tool, in this case a Hakko 808. The tip of this tool heats up to melt the solder, and with a press of the trigger an electric vacuum pump pulls the melted solder through center channel of the heated tip and into a chamber for later disposal.

The desoldering pump was able to remove more solder than hand tools could, but was still not quite enough to free the port. Using a soldering iron, some user-friendly leaded solder was worked back into the joints to mix with the remaining Dell factory solder. Upon second application of the electric desoldering tool, enough solder was removed to free the port from the system board with only minimal damage.

 

A test with the voltage meter confirmed this port is now ready to be used to provide ~19V DC power to a future project.

Socket Extraction Success