ZenLinux Blog

A while back I had picked up a neat little fanless Intel Atom computer based on the BayTrail N2807 CPU. It’s a dual-core system running at 1.6 GHz and has 2 GB of RAM and onboard flash disk, and seemed ideal as a micro server for my home LAN.

The device turned out to be a bit flaky to set up, so I thought I’d share my installation notes here. There are multiple revisions of this mini PC, and I believe I have one of the first versions. The case looks like this:

LIVA Mini PC

First, I created a USB flash drive with the Ubuntu 16.04 server install image using Ubuntu’s Startup Disk Creator app. Then, plug in an HDMI monitor and wired keyboard to the Liva. Hit F7 when the BIOS screen comes up and select the flash drive to start the installer.

The main issue I ran into was during the disk partitioning step. If I chose one of the guided partitioning options, the process wouldn’t complete, and raised an error about “Identical mount points for two file systems” on the flash storage.

After several unsuccessful attempts to try other options, I found a solution that worked. First, choose manual partitioning mode. Select the entire disk, and create a new partition table. Then select the free space and have it create partitions automatically. At this point I could save these changes and have the installer proceed past the partitioning step.

Everything else in the installer is pretty straightforward. Once I had everything set up the way I wanted, I disconnected the monitor and keyboard and intended to use the system as a headless server. However, the system refused to boot without a monitor attached. I tried several modifications to my GRUB bootloader command line to try to work around this, but had no luck. If someone knows the customization to make here, please let me know and I’ll update this post with the info.

Instead, I chose the lazy option. You can buy “dummy” HDMI connectors that emulate a monitor – for example here’s one that you can use.

Once I connected that to my Liva Mini PC, it was able to boot up headless and the device is now usable to me again.

I hope this information might be useful to others trying to make use of this handy mini PC system.

Over the last month I’ve had the opportunity to borrow/rent a 3D printer from a friend of mine. This was a healthy thing for me, since I had recently joined a local hackerspace (Brainsilo) to have access to a 3D printer a member kept there. With all the hype and excitement around 3d printing, I quickly got caught up in the possibilities and was overwhelmed with all the amazing things I could now potentially create, either of my own design or from sites like Thingiverse.

Having to actually go to Brainsilo to kick off prints was just inconvenient enough, and my ethusiasm just manic enough, that I started to seriously consider buying a printer of my own. Based on my research, one of the best values in 3d printing appeared to be the Printrbot Simple Metal, which you can buy for $539 in kit form or $599 assembled (plus shipping). Thankfully before I gave in to the desire to impulse-buy one of these, I worked out an arrangement to borrow this same model from a friend of mine who was starting to get a bit bored with it. In the end I worked through my obsession and gained more realistic expectations about what 3d printing could offer me.

I’ll reveal the conclusions now: it’s not useful enough for me at this time, but may be worth re-examining what options are out there in another year or so. But I will also say that the Simple Metal does live up to being one of the best value printers you can get for under $1k – I advise getting the heated bed accessory for it (another $100) and setting up an Octoprint networked print server.

My hope was to be able to use this printer to create useful things. A lot of people seem to use them for creating figurines and toys, but I wanted to build enclosures for various embedded boards I had (especially the RaspberryPi). I was disappointed with the results in a number of ways. First of all, printing anything thin-walled or with narrow standoffs wasn’t working for me, because it turns out that PLA is too brittle. Nearly all of the RasPi cases I tried printing fell victim to something snapping or cracking as I tried to fit the board into the case.

RaspberryPi Cases with Broken Parts

The solution here is likely to print with ABS plastic instead of PLA. That requires a heated bed, and the fumes of ABS are not something I wanted to deal with in my home office setup. Another issue which I assume would have been resolved with a heated bed was warping. I saw a lot of warping of anything that had a large surface area (especially embedded board cases). Printing with a brim mitigated this slightly, but still not enough. Printing with a raft fixed the warping issues, but as much as I tried to tweak the raft settings in Cura, the raft was always too strong and more or less ruined my prints when I tried to remove it.

3d printing is still pretty far from a simple usability experience. You have to learn the nuances of your printer, slicer, and even tweak print settings for every kind of filament you’re using. Hmmm….can I get away with printing this without support structures? Often you’ll waste hours trying a print without them and end up throwing it away. The process is quite tedious and iterations are slow.

I did have a few nice successes in printing, though. This particular RasPi B+ case from Thingiverse came out well (at least, the case doesn’t have any parts broken off of it yet, though I did have to tolerate some warping in the print). I have a solid set of parts to build this bulldozer battle bot. And I had fun with one of my neighbor’s kids building this 3d printed walking robot.

3d Printed Parts to Build a Bulldozer Robot

Overall I’d have to say it’s still worthwhile to wait and see how the technology advances. We’re still in the infancy of 3d printing, and improvements in quality, convenience, and price will be substantial over the next few years. Printing in PLA is mostly useful for toys and prototyping things to eventually make in ABS. Without the ability to print ABS conveniently in my home, I think a 3d printer is still too much of an expensive toy, and if I want a 3d printed item, I’m better off finding a local printer a site like makexyz.com and having them print in ABS and apply the specialized knowledge they have about how to optimize prints with their printer.

I recently decided it would be worthwhile to see if I could quiet my computer. It seemed like a good return on investment, given that I spend most of my waking moments sitting next to it.

I’ve always built my desktop systems from components, and generally pick quiet CPU coolers. My curiosity was peaked when reading about PC cases which are specifically designed to quiet sound. They tend to include sound-dampening material on all sides, as well as use specially-designed hard drive trays which isolate vibration from hard drives using rubber grommets. They also use larger intake and exhaust fans, which spin more slowly and quietly.

The best review site I’ve found for quiet components is silentpcreview.com. Having settled on the Fractal Design Define R3 case, I ordered it and figured it would just be a matter of moving the guts of my current system into the new case.

After spending a few hours performing the transplant surgery, I powered the system up and was shocked to find that it sounded even louder than before. It didn’t take me long to determine that it was my video card that was making the most noise. Somehow the quietness of the new case lowered the noise level of every other component, so the video card’s cooling fan was now the primary source of noise.

I haven’t played video games in years, and my current graphics card was likely overkill for running a handful of Compiz effects on my desktop. A bit more research led me to discover that there are a number of passively-cooled graphics cards on the market. Ironically, the one I chose is even more powerful than the fan-cooled one it replaced!

Today I installed the new video card, and the difference is too good to be true. My workstation is for all practical purposes silent – I have to strain to hear the fans. In my excitement I thought I’d share the relevant components I used:

Case: Fractal Design Define R3 w/ the two stock fans
Power Supply: Corsair VX550W
CPU Cooler: Zalman CNPS9900ALED
Graphics Card: Zotac ZT-40606-20L nVidia GeForce GT430

(This photo shows the build with my old, actively cooled video card in it)

Oh, and did I mention my CPU runs 5 degrees C cooler than it was in my previous case? You don’t need to cook your system to run it quietly with the right components.

As mentioned in my previous post, I now have a Sony PRS-T1 ereader – my first e-ink device. Rather than run down the specs of it and cover the same things everyone else mentions in their reviews, here are some links you can follow to other reviews which I found useful:

Engadget Review: Sony Reader Wifi

MobileTechReview’s video review

Gadget Review: Sony Reader Wifi Review

I’ve been reading ebooks on a Samsung Galaxy Tab 7″ Android tablet for a while now, and never realized until now how much nicer an experience it can be to read using an e-ink device.

Here are a few observations I haven’t seen mentioned in other reviews…

A lot of reviewers prominently note that the device uses a full refresh when turning pages. This is true. However, the Sony is capable of doing partial page refreshes, and does so when bringing up menu items or when using the browser. I’ve noticed some mild “ghosting” effects when partial page refreshes occur, and I’ve heard that this is a common problem on other ereaders which do partial page refreshes. The full page refresh when turning pages doesn’t bother me in the least, and I actually prefer it knowing that it prevents the ghosting problem from occurring.

One thing I have been disappointed about is the Google Books “integration”. I originally assumed that the Reader had the actual Google Books Android application. This is not the case. Instead, when you click on the Google Books “app”, it actually loads the Sony Reader application, but brings you to a section of their site where you can search for the free Google Books. You cannot retrieve or purchase ebooks directly from Google Books using the device. I can however download my purchased books from Google Books and then sync them to the Reader using a PC.

I do find it quite handy to have access to a web browser, even though scrolling on it is cumbersome with the e-ink refreshes. Here’s a tip – don’t use your finger to scroll the web page. The prev/next hard buttons will perform a page up/page down action on the web page, minimizing the refreshing latency.

The glossiness of the plastic bezel hasn’t really been an issue. It does attract fingerprints, but I also don’t really notice it that much. These issues could be resolved by getting a thin gel case if they really bother you. My guess is the type of people who get worked up about such things are also the type who can’t stand to break in the binding of an actual paperback book they’re reading. 🙂

Apart from the unwelcome surprise of the Google Books non-integration, I’m quite happy with this device. Also, there is news that the Reader has already been rooted, so in a short time I look forward to having the ability to install arbitrary android apps on the device. Google Books will certainly be one of them, as will ReadItLater.