Things of Flat Surfaces

 

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Old, but clean rope.

2009 NF Sonata Instrument Cluster Sorround Removal

I had trouble finding instructions for removing the Cluster Surround from my NF Hyundai Sonata. I want to mount a phone/GPS holder to the dash, but this requires drilling and thus access to the tender internal bits of the car. Most of the videos and guides are for pre-facelift cars. These basically have you remove two screws at the top of the cluster face, a panel right low the cluster over the steering wheel (this clips in) and pull out the cluster with suction cups or a strap around the back to overpower some clips at the back.

The 2009 and 2010 cars are a little different. Or, at least mine is. A lot more of the dash needs to come out.

(1) Remove two screws under the lip of the cluster sorround. A long screw driver lets you spin the screws with the handle below the wheel stocks

(2) Remove the fuse box door and then pull the entire panel side with the drivers door open

(3) Remove 3 screws: (1) Trim Piece (2) lower vent screw (3) upper vient screw

(4) Remove the thin trim piece that covers the lower edge of the sorround. It has 3 clips on the back

(5) Remove the vent

You can now tug on the sorround and free the left side.

(6) Remove gear selector knob

(7) Remove the left and right trim pieces beside the storage cubbies. These are held in by clips, pry at the bottom to get them started.

(8) Remove 11 screws holding in the cubbies (5 on each side and one in the middle bottom of the big cubby) These might not be layered but I didn't check. Remove the trim piece at the top of the big cubby.

(9) Remove the vents and AC controls. These are clipped in. Pry carefully.

(10 Cluster sorround should now be free of obstructions and pop out.

My Ubuntu ZFS on Root Gripe List

I sort of love Ubuntu ZFS on root and sort of don't.

I have a lot of complaints.

(1) Almost completely missing documentation. The entire knowledge base is centered around Didrocks blog.

• How do you add datasets to zsys?
• How do you backup/restore this?
• zfs complains that the pools can be updated to use new features but it's not clear if this is safe.
• Unclear about how zfs volumes were setup. How frequently does this scrub and trim? (not very)

(2) Poor handling of file systems with lots of changes. This sounds like an edge case, but if you use steam to manage a games library and do some video or photo work on the side, you're going to find a lot of snapshot induced storage bloat. I've had to reduce the snapshots held in zsys.conf. 

(3) bpool size is too small for the kernel image rotations. I end up having to manually remove old kernels and snapshots. Complaints of this are extremely common. You can, with some pain, replace the bpool with a larger one.

(4) Unclear behavior in recovery mode. If I go back to an early snapshot, is the current dataset still fine? What happens if I make a change? -Confused-

(5)  Snapshot names are cryptic. I would have hoped for something like an ISO timestamp and a simple iterator.

(6) No configuration options at setup. Going back to the above, having a sane default is/would be great, but adding ZFS options and setting the sizes of bpool and dealing with complex zfs pools would be useful in the installer.

Overall, zsys seems like requires an understanding of ZFS to run with confidence that you won't suffer some catastrophe in an edge case. It so opaque that it's a big tradeoff to commit to zfs on root, as you need to really understand ZFS to use it, but at the same time, if you're that into ZFS, you'll find it frustrating.

Ubuntu 22.04 LTS Starts In Emergency Mode: no network drives, snapd apparmor failure, and can't mount /boot

 I sort of love Ubuntu ZFS on root and sort of don't. A main gripe have been almost completely missing documentation. The entire knowledge base is centered around Didrocks blog.

Yesterday, I started my computer from a cold start, logged in, realized I meant to turn on virtualization in the bios to use virtual box, restarted within maybe 60 seconds or less of logging in, tweaked the bios, and restarted again. Instead of a clean boot, the system started into emergency mode. I guessed that something about virtualization extentions was causing problems, and restarted, set the bios back, and restarted again, but the system still would only get into emergency mode.

journalctl -xd errors noted

(1) Snapd.apparmor errors for firefox

(2) Couldn't mount network samba shares

(3) Couldn't mount /boot

(4) bpool was missing from zfs list  

Disabling app-armor in grub did not resolve the issue (some people have had corrupted app-armor installs). Apparmor failure maybe were a symptom?

Disabling network shares did not resolve. This was a symptom of the network stack not working.

I kept focusing on fstab. I tried mounting the vfat partition labeled /boot on my ssd. This did not work. But I recalled that zsys does some kind of rotation with bpool and /boot.

Maybe something was keeping zsys from mounting boot? Did it "forget"?

I am still not sure how to guess how to mount the correct bpool to /boot.

I found this reddit discussion where someone converted a /dev/ to a uuid fstab:

https://www.reddit.com/r/zfs/comments/n26j2f/has_anyone_been_able_to_convert_ubuntus_zsys/

 Based on that, after entering emergency mode and finding that 

mount -a

could not mount boot from fstab, and that bpool was not in

zfs list

zpool list

I ran

zpool import -d /dev/disk/by-id bpool

Which correctly mounted bpool to /boot. I then exited emergency mode and the computer started normally.

I have no idea what happened...

Dell Laser Mouse (M-UAV-DEL8) Repair Notes

I used a cheap and fairly commonly available Dell Laser Mouse (M-UAV-DEL8) for many years, and really liked it, as it provided all the features I wanted in more expensive mice (laser tracking, decent response, on-mouse tracking adjustment, and a scroll wheel with some buttons in places I could manage. I had two over time.

Over time the quality of the tracking started to deteriorate and the mice eventually became essentially unusable. Cleaning the lens under the mouse and applying compressed air or suction from a vacuum cleaner didn't improve the performance. I assumed that whatever cheap sensor or other electronics in the mouse were dead and I purchased a new mouse and the Dells went into the junk pile.

Years later, i wondered what was up and decided to open the mice for cleaning. It turns out that the optics sit on a wide piece of clear plastic and it catches dust and debris from the top of the mouse, but this is very difficult to remove without taking the mice apart. Cleaning the sensor brought it back to full performance. I also cleaned the scum from scroll wheel mechanism and inspected the click-switches.

Repair notes: 

Disassembly: 

The mouse comes apart easily. There are 2 Phillips screws under the rear skate pad. The rear pad can be removed non-destructively with knife and replaced.

 After removing the screws the mouse has two circuit boards connected with thick ribbon cables. These boards are on both halves of the mouse. You can remove the top board from the mouse by moving it left and right relative to the bottom and removing the two retention screws. 

The bottom circuit board has the side click buttons in the way. The buttons can be removed with a thin prying object like a knife or small screwdriver by prying the retention tabs inward and pulling up on the buttons.

After that, there are 2 screws in the bottom circuit board and the electronics and scroll wheel will just slide out.

 

Laser Optics/Lens:

To remove the lens from the bottom for cleaning, there are two small tabs that are melted into blobs on top of the laser sensor. Cut the tabs with a knife and the lenses will fall away. You can clean it with a paper towel and isopropanol. I noticed that you can see the dirt on the optics with the white towel behind it... this makes getting it clean easy... it took more than a few wipes to get it spotless.

I reattached the lens by putting 2 small dabs of hot glue on the outside fingers of the lens that go on the outside of the laser sensor.

 In the photo below you can see the big air gaps around the laser sensor, and the big lens tray that collects material that falls on it and prevents cleaning from the outside.

Scroll wheel:

I would call this a second generation scroll wheel: it has a stub that goes into a mechanism that sends pulses when scrolled and supplies the rotating resistance. You can pull the wheel out of the mechanism for cleaning.  There is a spring that provides the resistance for the scroll wheel click mechanism that is on the other end of the shaft, this catches on two small towers over the scroll wheel click switch. (I thought it was supposed to slide between the towers, but assembled this way it becomes obvious that is not correct).

Mouse click switches:

In the mouse that I paid attention to, these are Omron D2FC switches. They are through hole, so if double click issues showed up, they could be replaced. You can also attempt to repair the switch mechanism. The tops of the switches pop off by gently prying the small retention tabs of each side of the switch (be careful not to loose the small white actuator inside). I cleaned the contacts but did not attempt any spring bending. I measured the switching voltage, it's 5V, so I think they will go for a very long time.

Weights:

I removed the weights from the mice. They are held in by a single screw. At some point, a mouse is too light for me, but my preferences have moved away from heavy input devices over time.

Design notes:

To my surprise, these were made by Logitech for Dell. While I think they are somewhat unique, they have a BOM and design. (single sided PCB with through hole parts and very limited complexity) that is typical for a cheap 2000's mouse, but the core microcontroller and laser sensor are on par with some nicer mice in the era.

 

The mouse microcontroller is a Cypress CY7C64823 (Datasheet: https://www.infineon.com/dgdl/Infineon-CY7C63310_CY7C638xx_enCoRe_II_Low_Speed_USB_Peripheral_Controller-DataSheet-v21_00-EN.pdf?fileId=8ac78c8c7d0d8da4017d0ecc994f46c9). Nothing fancy, but it's interesting to see from the datasheet that Cypress has software that lets you basically build the mouse/input device characteristics from their library. I wildly guess it's running between 12 and 24 mhz. It can also support both low speed USB and full speed USB-2. It has 256 bytes of memory and 8 kilobytes of program storage (flash). This is a 24 pin surface mount device that I think could run directly from the ~5V USB bus with little power conditioning. I regret not following the traces, I wonder if it is using all the GPIOs? 8 button functions (Left, right, forward, back, scroll up, scroll down, scroll button, resolution), the USB bus (2 pins), and an SPI connection to the laser sensor make that seem unlikely.

The optical sensor is an Avago ADNS-7550 (Datasheet https://datasheetspdf.com/pdf-file/913766/AVAGO/ADNS-7550/1)  Notably the sensor features the same 400/800/1200/1600 DPI that matches the dell and logitech literature, as well as a 2000 DPI mode that isn't used by the mouse. I didn't track traces, but from the spec sheet, it looks like a minimum implimentation is an SPI connection to the micro controller, along with an interrupt line from the mouse to tell the controller there is activity, and then connections to 5V power from the USB bus.

The spec sheet has some interesting charts showing how the sensor acts on different surfaces.

Mine were made around 2008 or 2009 according to the date code.

It looks like, between the two mice, there were several revisions to the circuit board over time based on the revision numbers printed on the silk screen.

Spring is Creeping In

 

The Volvo 740 manual clutch situation is nuts.

 Years ago, the plastic clutch pedal in my Volvo 740 broke where the pivot meets the master cylinder cleavis. Cool. I put a huge bolt through the pedal with some epoxy and a band clamp and drove it for a decade before the epoxy broke and I had to redo the assembly. At least that time it failed in the driveway.

 Last week after a long slog through stop and go traffic, I thought the clutch was feeling clicky... like something was catching on the pedal. The next day I investigated, and after pumping the clutch a few times, it the pedal gave a pop sensation and went limp. A glance under the car showed the slave cylinder piston pushed out of the cylinder with a giant splat of hydraulic fluid. I gently reseated the piston, and to my surprise, the clutch works fine, though I have a new slave cylinder on order, as I think this means that there is a small air leak or contamination in the bore and I will be inconvenienced in the future if I don't get on it.

Of course, ordering parts was not straight forward. There's still a parts shortage from the supply chain problems, and there's mysterious gaps in the old-Volvo aftermarket parts catalogs. For some reason, IPD didn't list any cylinders for my specific model year. There are multiple types of clutch release arms, but the hydraulic ones are mysteriously hard to find. I want a clutch pedal I can trust to step on, but the OE plastic ones are seemingly no longer made, so you're on the hook for making your own or buying a metal one from europe.