Archive for October, 2011

Wormbin: resurrection complete

Posted by Vitalie Ciubotaru

Well, it’s getting cold outside, which means that it’s time to think about preparing my wormbin for winter. Let me write about what happened (and what didn’t) in my bin since my last report.

The worms got many

I should count weigh them one day and see exactly how many there are. I far as I can judge after the last [partial] vermicompost harvesting, they are more than the half-kilo that I bought two years ago, and MUCH more than what I managed to “resurrect” last spring. Must be around a kilogram of wigglers there.

The BSFL are still there

Not that I like them more than before (actually, I still find them quite repelling), but I was wrong about them. I used to think they don’t get along with worms. BSFL are pretty large and very active, so I thought worms would be stressed to have them crawling around. BSFL eat very quickly and leave a very wet mess after them, so I thought the bin would quickly turn anaerobic, something that worms don’t like. I thought BSFL might prey on worms, or eat worm cocoons. Judging by the number of worms, I was wrong.

Somehow they manage to cohabit. After I covered the whole surface of the bin with a piece of cardboard, I noticed that they have a distinct pattern of behavior. Worms and BSFL tend to occupy different parts of the bin, but usually stay close to each other. When there is food, BSFL stays in the top layer of the bin and eats, while worms stay close to bin walls, also in the top layer (not sure how they are distributed deeper on). When there is nothing for BSFL to eat, they stay close to the bottom, while worms take over the whole surface, right under the cardboard.

Indeed, when there’s new food, it’s BSFL who come first. After they are done, there’s usually nothing but a very wet and somewhat smelly substance left. Worms to not mind hanging around in it (usually, by that time there are no BSFL in the area), so I think they convert it into castings, just like everything else.

As for the potential vermicide threat, I am pretty sure BSFL don’t touch worms. On the other hand, I can’t be 100% sure that BSFL do not feed on cocoons, because somehow I didn’t see many cocoons lately. Let’s hope for the better.

There’s vermicompost to harvest

A couple of weeks ago I decided to refresh my bin by harvesting castings and adding new bedding. As harvesting ALL castings would have been too stressful for the worms and too time-consuming for me, I decided to to do it in parts. An important observation for me was that worms are more active in the upper layer of the bin. They don’t just feed there — they also lay the castings there, which is against the “theory”. Although it’s quite moist in the bottom part of the bin, I found more unprocessed paper and cardboard than in the top part. Who knows, maybe the lower layers are too packed for them, or insufficiently aerated.

I stopped just short of clearing half of the bin. The reason was very prosaic — no cardboard. What I regarded as a good source of bedding turned out to be “Good, new boxes. Don’t touch them!” :-) So instead of mixing cardboard with shredded paper I had to do with shredded paper only. I don’t like paper much, because it tends to get too packed, and worms are usually slow to colonize it. At this point I can’t move on with harvesting, because my worms would be left with no “home” to live. And I can’t move on with adding paper, because I’m afraid I’ll end up with a lot of packed cellulose pulp. That’s OK, I can wait.

Building a case for my mini-ITX board

Posted by Vitalie Ciubotaru

Previous posts on this topic:

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There’s a dozen of questions that I have to answer before embarking for this adventure.

  1. What shall I do about hard disks? If I want to have a hard disk (or two) inside the box, then I’ll have to provide space for it and to think about some sort of mounting rack/case to fix the disk to. If all disks will be outside, the size of the box will be much smaller, but there will be extra cables to plug/unplug every time I want to connect a disk (this is especially unpleasant with SATA disks, which, to my surprise, seem to require extra power even when connected to USB). Inside is better.
  2. What shall I do about power supply? One way is to use the standard ATX power supply I own (and use right now). The other is to find a cheap DC-DC adapter board (like in car computers) and use a laptop-type PSU. Besides these obvious options, I could get a smaller PSU (like TFX, SFX, FlexATX) and toss it inside. Gotta find out what dimensions they have.
  3. What shall I do about cooling? The easiest (and coolest, to me at least, would be to leave two opposite sides uncovered and to drill several holes right above the CPU radiator. Additionally, I could mount a fan somewhere. This shouldn’t be difficult — although it’s a fanless board, it preserves connectors for a CPU fan and a system fan.

Then there is a series of less important questions:

  1. Shall I use the onboard USB connectors and have USB ports on the front panel?
  2. Shall I use the onboard Audio connectors and have extra Audio on the front panel?
  3. Shall I use the PCI slot? If yes, what shall I insert in it — a WiFi, an IDE riser card, another Ethernet card, a CF card reader, or…?
  4. Shall I add another 2Gb of RAM?
  5. What about NAND Flash memory?
  6. What to do with the front panel leds and buttons? Making a button myself is not exactly a trivial task, but tapping a screwdriver to the power switch headers on the board every time I need to turn it on is not a good solution either.

Anyway, I have already purchased a 300x450x3 mm sheet of black plastic (have no idea how that material is called). If With luck I think I can do with this amount of plastic.

UPDATE (Oct. 24) The set of two six-wire cables (power switch, HDD and power leds, no reset switch) that I bought on ebay arrived today. A two-way IDE-to-SATA and a 3.5IDE/2.5IDE/SATA-to-USB adapters are still somewhere on their way.

UPDATE #2 (Nov. 1) The 2-way SATA-IDE converter arrived today. It is a bit different compared to the picture on eBay — it has a couple of jumpers, which miss on the original picture. It took me a while to figure out the correct position of the jumpers and get it working. First, there is a legend to the jumpers, but it’s on the other side of the board. Second, to make it work one has to connect power to both the disk and the board, which is counter-intuitive. Anyway, after several tries I connected my 3.5” IDE disk and I can access my pictures again.

UPDATE #3 (Nov. 2) The everything-to-USB adapter is here. I did not test it yet, but it looks so simple that I can’t image what can go wrong.

UPDATE #4 (Jan 10, 2012) A trip to Akihabara resulted in a small (TFX?) power supply box.

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Followup posts on this DIY project:

DYI computer based on an Atom miniITX board

Posted by Vitalie Ciubotaru

Usually, when I travel around Kansai, it’s sightseeing that I’m mostly interested in. Every time I try to visit a new place and in most cases I don’t visit the same place more than once. However, there’s one place I tend to visit again and again, although I don’t see any noticeable changes about it. The place is called Den-Den Town.
I don’t go there to buy something specific, just for sightseeing. Most of the time I can’t restrain myself from buying another [useless] piece of computer hardware. My last visit resulted into a new motherboard, RAM and a hard drive. Almost an entire computer :-)

The motherboard is an Atom-based mini-ITX fan-less board made by Foxconn. A small and quiet board is one of those things I’ve been pondering about for months, reading reviews, looking at Ebay price tags and swinging between utility and passion. Usually I focused my attention on VIA’s C3/Eden/C7 boards — they are cheaper, though less productive. The purchasing decision was pretty much spontaneous — I just came across several mini-ITX motherboards. This board happened to be cheaper than the VIA-based competitor, so the decision was made.

A quick look at the specifications revealed that it requires DDR2-800 (aka PC2-6400) type memory and SATA-type hard disks. I didn’t have either, so two other purchases followed: a 2 gigabyte memory module and a 40 gigabyte disk. To make a working computer I needed to add a power supply, a display, a keyboard and a mouse.

Until now all computers that I had to (dis-)assemble were based on Pentium III, so I was a bit surprised to find out that the power supply should have 24 pins instead of 20 pins, and that a new beast, called “P4 connector”, emerged from nowhere. Luckily, the power supply unit that I found in my computer case was the right type. Add my spare keyboard, a nobody’s display I found in my lab and my stylish black-and-yellow mouse that reminds me of Lamborghini Diablo and Need for Speed 3, and the DYI computer is ready. By the way, there’s a real lot of nobody’s hardware, mostly junk produced 10 to 15 years ago, probably abandoned by folks who’d been imprisoned here before myself.

It’s time to turn it on. However, in order to see it run (or fly!) we need an operating system. First, I connected the SATA disk that I bought and an external disk (originally internal, taken from a deceased IBM Inspiron laptop, but turned into an external USB device) and switched the newly assembled computer on. “Switched” doen’t mean “pushed a button”, because the computer didn’t, and still doesn’t, have an on-off button. Instead, I had to use a piece of metal to connect the power-on pins on the board. The motherboard is fanless and thus absolutely quiet, which is why I could judge whether it’s booting only by the sound of the system beep and the old hard disk (the new one is very quiet, too).

It happily beeped and started booting. I hit “Delete” to make sure that both drives were detected, to see if the memory was the promised type and size, and simple to wander a bit through the BIOS. When I tried to adjust system clock the system hung, maybe because I used the numpad, not just up and down keys. Whatever was the reason, it was the only case of unexpected behavior so far. From the second try I successfully changed the time, then changed the first booting device to USB and happily booted into my Kubuntu/Trinity 10.10.

While I was googling and figuring out how to install an OS on the SATA drive (I only had an install CD), another surprise popped up — Atom is a 64 bit, not 32 bit, processor! Well, this meant that I would have to install a 64 bit version of Kubuntu. After some hassle (QEMU refused to load a 64 bit CD image, the image got copied onto a flash drive without the bootloader and refused to boot, GRUB2 refused to boot CD ISO from the hard disk etc.) I installed an OS on the SATA disk and finally booted into the shining new 64-bit version of Kubuntu.

Well, that’s where I am now — I’m writing this post from my barebone computer in my lab. There are two issues left on my agenda. First, I need to get some sort of casing for my new beast, and second, I need to come up with an idea about how to use it. Difficult questions…

I have almost zero experience working with plastic or wood, almost zero tools for such a project, and zero, without the “almost”, experience making computer cases, but if I am to use all the advantages that this computer offers (small size, no noise, portability etc.), then I absolutely need a case for it. I already bought a IDE-to-SATA adapter for my 3.5” IDE disks (I think I have three such disks and one of them holds all my photos) and a set of front panel connectors (power and reset switches, and power and HDD leds — I’ll finally be able to switch the machine without a screwdriver). Now I am choosing between wood and acrylic glass, and thinking about the size and shape of the future case. Anyway, I have a fallback solution: I can always give up and simply put everything in the old large case, where the PSU comes from.

The second question is how to use this machine. Should I turn it into a home file server (on local hard drives and on Dropbox, Ubuntu One etc.) and let it just sit around gathering dust somewhere in a corner? Should I design it as a portable nettop-like computer and carry it with me back and forth? Can it serve as a standalone WiFi access point with a web server (e.g. hosting a MMORG for my lab colleagues :-))? Other ideas?

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Followup posts on this DIY project: