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Category: making things

Tyan Transport GX28 (B2882)

I just hit submit at to complete the purchase of a Tyan Transport GX28 server with a Tyan Thunder K8S Pro (S2882). As item number N82E16856152008 the barebones server was only $409.99, with $31.24 shipping. Thanks to a friend helping me out with some RAM and some disks which I’ll be able to make redundant I’ll likely end up with a 1U server with a pair of Opteron 800-series CPUs, 8GB of RAM, and mirrored 500GB SATA disks.

This all brings about an interesting question of where to host the new box. I’ve discussed this before, and the more I think about it the more I want to get my box out of Waveform. Things are working fine for now, but I question what will happen if or when the box does start to have problems. The provider I’m most seriously looking at would run $100/mo

So, now I just have to wait for things to be shipped and delivered and then I can start assembling it all. I imagine I’ll let it cook for a few weeks to a month before installing it. It’ll be running FreeBSD 7.0, likely with a custom kernel and world rebuilt specifically for the CPU. I think I’ll also want to give the new ULE scheduler a go, particularly after seeing this presentation (PDF) about where FreeBSD is going.

I’ll continue to stick with lighttpd, although I hope that the OpenSSL bug in 1.4.19 is fixed in ports soon. Disks will likely be mirrored with gmirror, although I will investigate the on-board hardware RAID. I’ll probably also stick with MySQL for the db and Postfix for mail. Basically, nothing will change in that regard.

I may opt to eliminate some individuals I currently host from the box, mostly because I never have contact with them. I don’t mind hosting people, but when the sites sit mostly unused and I have almost no contact with the individuals who use them (except when there are problems, of course), it’s a bit frustrating to keep up maintenance on apps running on the sites. Also, this new provider has stricter limits on bandwidth (1mb, 95th percentile), and I need to be a bit more careful about how it is used. Anyway, if I’m opting to remove your site from hosting I’ll contact you outside of here and provide you with a chance to get your data.

For now I wait, then build. This could be pretty nifty. Oh, and the colocation provider offers IPv6 at no extra charge, so that ought to be fun to play with as well.

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Failing PLED?

Two lines of display on the failing PLED during bootloader update. Note that the second line is more faint than the first, pixels are smaller than expected, and there is distinct fading around the edges of the display.

Last night I made quite a bit of progress on Ivan’s P3, getting it up and running, but I did run into a few problems. First, as can be seen above, the PLED which came with the enclosure seems to be failing. It will either display no text, one line of text, or (rarely) both lines, and every time pixels seem small and dim, with the edges of the display fading to nothing. Only a power cycle of the P3 seems to (re-)activate non-working parts of the display. As the P3 still functions even when nothing appears on the display, I believe that it’s actually the display elements of the PLED which is failing.

Here is the PLED in my P3 from 2006, and when it is compared with these two images (1, 2) of the PLED from Ivan’s P3, it seems pretty obvious that something is wrong.

Thankfully there was a spare PLED in the package of parts I received, so tonight I’m going to try that one instead.

Second, I’m not happy with the cables I made for connecting the tempo and data pots to the mainboard, so I’m going to remake them. The tempo pot connection seems to be a bit flaky, so I’m not sure the pins are properly seated in the connector. The cables are also short enough that they are difficult to connect, so I’ll probably redo them with braided 24 gauge hookup wire or something like that.

Finally, the v1.5 mainboard construction notes indicate that when the P3 is being set up for MIDI sync, D2 and D3 should be replaced with 220pF caps in order to add a bit of extra capacitance to the lines to work around false triggers. I didn’t have any 220pF parts, and none came with the kit, so I instead used 330pF parts. I don’t believe this will be a problem, but I made a post to the analogue-sequencer group asking for confirmation.

Beyond those three problems, the build is going quite well. I’m very happy with how both the step board and keypad came out. The IDC ribbon cables, their connection, and power input stuff also worked out great.

I was also able to get the latest bootloader and v3 firmware on the P3, which means that as soon as the other issues are sorted out I can get the MemX and latest v4 beta installed. After that it’ll just be time to install the knobs, test it out, and ship it back to Ivan.

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Good Progress on Ivan’s P3

Detail of the bank of 12 resistors in the lower right corner of the mainboard PCB. I like how these look once fitted.

Today I made a bunch of progress on the Sequentix P3 I’m currently building. Before today I’d only checked out the parts to be sure most of them were there, looked over everything, and did some general setup to be sure assembly could progress. Today I started fitting pieces, and I’m definitely more than half done at this point.

Because this P3 uses a slightly older board set (v1.5) I had to use this set of older DIY Sequentix P3 directions, but this didn’t prove to be too difficult. While I was able to complete the mainboard, I had to make some slight modifications. It seems that the v1.5 P3 board set only supports MIDI sync or DIN sync. One must read carefully through the main board and IO board pages to figure out what extra components to add, which to leave out, and what to do differently. In short, I had to leave out some parts from the mainboard and fit two capacitors where diodes once went and add in an extra pullup resistor on the bottom of the board.

The two capacitors on the top of the board are intended to add a bit of capacitance to the input lines of the PIC which handles MIDI sync. It is suggested that 220 pF parts be used, but as I didn’t have any of them I fitted some spare 330 pF parts. I don’t think this will cause any problems, and hopefully it won’t. The extra resistor on the bottom of the board is to help work around slow rise times on the MIDI output caused by additional capacitance brought about by the inclusion of RFI filters on the IO board.

I’m hoping to be able to power it up for the first time either tomorrow or Tuesday. How late I get home from work will determine how much I’m able to get done each night.

Here’s a few more photos of parts from tonight:

· Completed Mainboard w/o ICs: Top / Bottom
· Completed upper and lower pot boards.
· Pots for the P3, plus spares, with lugs removed and thick 1/4″ washers fitted for spacing.
· Completed IO board, set up for MIDI sync.
· Completed function switch board.
· Twelve resistors.
· Incomplete keypad board with 1N4148 diodes fitted.

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GPS Logger and Bike Riding

As shown earlier and resulting some KMZ files, I will frequently clamp my GPS to the handlebar of my bike and log where I’ve ridden. The problem I’m finding is batteries… The older Garmin eTrex Legend that I have will chew through a pair of disposable AA in an hour and a half, and good rechargables don’t last beyond three. This is short enough that it’s starting to become a hassle to use the thing. On top of that, dumping the data into a computer sucks down even more battery.

I’m thinking that my next electronics project should be a low power GPS logger that either writes to some local flash, or to a microSD (or whatnot) card. I think that one of the random modules from SparkFun, a PIC, a off the shelf FAT library, a FT232R could make it all work nicely. It could recharge via USB and have a couple basic buttons and LEDs for resetting saved logs or whatnot. All I’d need to do is ensure that it’s in a standard format (shouldn’t be hard) and GPSBabel will be able to make it anything else I’d want.

Now, since I just rode ~21 miles, I’m going to go shower then get back to work on Ivan’s P3.

Oh, and look at this: FTDI’s USB to USB null modem cable (PDF Flyer). I could really use one of those too.

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Beginning Ivan’s Sequentix P3

Most of the parts for Ivan's P3 laid out on a table next to my workbench for easy selection.

This afternoon I ran by the local FedEx depot at the intersection of Brown Road and Giddings Road in Auburn Hills to pick up a box containing the next P3 I am to build, for another person from the analogue-sequencer Yahoo! Group. It turns out that this facility doesn’t normally receive in-person pickups, as I had to enter through the employee entrance (metal detectors and all), enter the office, and just sit in a waiting area until the person brought out my package.

After a nice bike ride around Dodge Park with Danielle I opened up the package containing the P3 and started sorting through all of the parts, laying them out on the table for easy access. On initial glance everything seems to be there, except for a couple small screws for holding the enclosure together.

This is actually a slightly older enclosure design than I worked with on on my P3, as it doesn’t include niceties like the subpanel to help with the pot assembly, and the clearance around and mounting of the PLED leave a bit to be desired. That said, I imagine assembly will go pretty smoothly.

I’ll get started with the actual assembly tomorrow, although I might take a break for a bike ride if the weather isn’t too threatening.

Oh, and (per usual) there are a few more photos of Ivan’s P3 here in this album in my gallery: Sequentix P3 for Ivan

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Broken U Bolt On Hitch

This is what happens when one uses a torque wrench expecting it to work right, without a understanding of what 20 foot pounds feels like. Before heading off to the park with Danielle, I decided to take my new (and admittedly cheap) Michigan Industrial Tools torque wrench and check the torque on the bolts on my hitch.

I set the wrench for 20 foot pounds, put it on the bolt, and pushed. Since the torque wrench is supposed to click when it reaches the amount of torque specified, and I didn’t hear any click, I figured it had to be tighter, so I pushed a bit more. The bolt turned, then I pushed a bit more. Suddenly there was a BANG and the bolt clattered to the ground having broken off.

Later in the evening I hooked the torque wrench to another wrench and tried it out, applying force every way I could think of, and it wouldn’t click. I played with it a bunch, turned the adjustment all the way in and out a few times, applied more force to it, and after about 20 minutes of playing it finally freed up and started working. I then found out how little force 20 foot pounds actually is.

It took my working the adjustment part of the tool back and forth a few times, and then applying a solid amount of force opposite the direction the torque wrench should be used in (that is, against the arrow) before I felt something loosen up inside the tool and it started working.

So, it turns out that the problem seems to have been caused by my lack of knowledge and the torque wrench’s generally being crap. I’m still torn as to whether or not I should return it. Sure, it only cost ~$30, but if it’s not reliable it’s not particularly useful.

The bigger problem is finding another bolt. What I need is a 3/8-16 u-bolt, for 9/16″ outside diameter pipe, but I can’t seem to find it. Checking both McMaster-Carr and Grainger, all I can find is 1/4-20 parts at that spacing. McMaster-Carr lists the 1/4-20 stainless steel part as having a working load limit of 435 pounds, which is probably 4x or 5x what the bikes and hitch weigh. I’m not sure if it’s enough, but it might be my only choice.

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Sequentix P3 #008 Is Complete

Well, that’s it. Mark Pulver’s Sequentix P3, serial number 008 is complete. I spent a good part of the evening tonight finishing it up. The biggest part was making this custom, reversing DIP28 to DIP28 cable so that the MemX expansion which was giving me problems yesterday could instead be mounted next to the main PCB. I then stuck the MemX down to a freshly cleaned case with two layers of foam adhesive.

I also replaced all of the mounting hardware for PCB which holds the MIDI ports with some slightly taller pieces. This made it so that the DIN5 / MIDI ports are properly centered in the cutout in the enclosure.

After being sure it was working I closed it up and gave it some final tests using a Radium 49 and MIDIbox SID-NUXX for testing the MIDI inputs and outputs. Everything is working, so this means its done and is ready to go back to Mark. That’ll be tomorrow’s task… Hopefully the post office won’t be too crowded.

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Sequentix P3 #008 Is Working

It works, it’s running with one of the v4.00 beta OS’, and it’s almost done.

Tonight I did most of the final work on Mark Pulver’s Sequentix P3. This included making the cables, connecting the display, mounting the pots (complete with washers for support as mentioned yesterday, hooking everything up, and fixing any mistakes.

It turns out that I had two small errors which caused me some stress and parts of the P3 to not work, but they were easily sorted out. The first problem was an unsoldered pin 1 (OE) on one of the 74HC573 ICs. This made the whole thing act quirky, almost as if buttons were randomly being pressed. There was even odd garbage appearing on the LCD.

The second problem was that I put the 1N4148 diode on the pot function switch backwards. You can see the error here. The misplaced part is D9. This caused the button not to work and was real easy to troubleshoot.

I also found that the DIN5 MIDI ports on the back of the enclosure sit too low, making plugging and unplugging cables difficult, if they can even reach. Putting an extra M4 nut on each post beneath the PCB raises it up enough, but shorts me on M4 nuts. I’ll see if I can get some more tomorrow.

Upgrading the firmware to the v4.00 beta 26 to support the MemX memory expansion module was a bit of a hassle, simply because I kept receiving a BAD DATA error every time I tried. I originally thought the problem was due to some MIDI routing weirdness caused by new MIDISPORT drivers or MIDIOX, but in the end it was simply a firmware version compatability issue. This was resolved by using a bootloader update found in the analogue-sequencer file section.

After getting to the v4 firmware I ran into two other problems. First, capacitor C3 was tall enough and located in such a place on this old version of the PCB that the MemX board simply wouldn’t plug in. This was resolved by replacing C3 with a new 10μF 25V electrolytic cap, but mounting it on its side to be lower profile.

Then, while putting it all back together, I ran into what’s probably the biggest actual problem of the whole assembly: the case won’t close with the MemX board fitted. The place where the MemX board sits in the enclosure just happens to be directly below an IDC connector and the pot board. With the MemX fitted the case stays open about 1.5cm. With this large of a gap I can’t move the board sideways to avoid the connector because then it’d just hit another PCB.

As you can see above I was able to finish up the knobs and get the case mostly complete. As soon as I talk with Mark and figure out what he’d like to do with the MemX board (leave it out and sell it, or see if I can find another way to fit it in, which may not be possible) I’ll be ready to finish up testing and ship it out. All the buttons and pots work as expected. The display does its thing, and MIDI in works. I just need to test MIDI out and maybe sequence a couple things with it just to be sure it’s working and it’ll be done and on its way back to Mark.

Per usual, there’s a bunch more photos to look at. The ones taken tonight start on page 3, so help yourself if you’d like to see them.

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Sequentix P3 #008 Continues

Last night I did a bunch more work on the Sequentix P3 that I’m building for Mark Pulver. Unfortunately last night was the time where I started to see issues with the project. In short, I now understand why Colin moved away from not very many people used this case design for the P3. On top of the poor button / pot / LCD layout, the tolerances on the case just aren’t very good.

Here’s a rundown of the problems:

Step Switches: I fashioned a jig to hold the 1-16 buttons in place on the step switch / LED board, and that worked rather well for aligning all the buttons in a nice row, and they automatically lined themselves up with the holes in the PCB. Unfortunately, the screw holes for mounting the PCB aren’t perfectly in line with the slot cut out for the buttons themselves. The end result is that on the left side of that row the buttons are about 1mm lower than on the right side. The buttons all work fine, but they just look a little off.

Function Switches: The way the holes are drilled for the function switches, along with the alignment of the screw holes, the red (key function) button rubbed a bit in the hole. A little bit of filing cleared this up.

LCD Alignment: With the stock LCD for this original P3 enclosure fitted, it doesn’t quite line up with the hole cut for it, leaving the bottom and left side of its bezel visible. This may not be an issues as the actual displayed data will likely be centered, but it doesn’t look as good as it could. Additionally, the mounting holes are not physically compatible with one of the PLEDs used in later P3s. It may be possible to get the PLED to fit, but this would require a bit rigging, possibly involving cutting the corners out of the PCB and fashioning some sort of mount.

Potentiometers: The P3 uses analog pots for a number of inputs. This works very well, except pots (as seen above or here) have small tabs sticking off of them. These tabs are normally fitted into drilled holes and they keep the pots from rotating during assembly or use. The subpanels for the newer P3 enclosure have holes for these tabs, but the original enclosure on Mark’s P3 doesn’t. Because of this, if I were to tighten down the pots they would be bent to the side. To work around this I’ll just snap off tabs (a trivial process, really) and then stack some washers between the panel and pot body to space things as nicely as possible. This will allow the mounting hardware on the pots to be properly tightened.

Now, that out of the way, the good things: I had no problem getting all the LEDs fitted / mounted / nicely aligned in the panel. These are all soldered into place and the PCBs holding them can pretty much be removed at will. All ICs have been fitted into their sockets, and things are progressing quickly towards the ever-so-scary first powerup.

Oh, I also had no problems making a jig out of cable ties and an old heatsink and blue masking tape to handle alignment of the keypad. I’m really happy with how it came out, and thankfully its mounting is not misaligned in the front panel like the other keys.

Next, and hopefully tonight, comes the boards and pots and switches and such together, finalizing mounting of the pot boards, and hopefully getting it running for the first time.

After making this post, Colin Fraser corrected me with regards to the case design. This case is actually the Maddox design. The original Sequentix P3, of which only four exist, can be seen here.

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Another Sequentix P3

Thanks to the analogue-sequencer Yahoo! Group, a discussion group for individuals interested in the Sequentix P3, I ended up getting in touch with a guy by the name of Mark Pulver who was in need of having his Sequentix P3 kit assembled. I sent him a link to my Sequentix P3 page at and photos of my P3 assembly and I imagine he liked what he saw because he asked me to assemble his.

After languishing in transit for a week and a half between his place and mine, I stopped off on the way to work and picked up the package from the post office. It was a quite large, well-packed box which should be just about right for safely shipping it back to him once it’s assembled.

Before getting to work I had to dig around for a while and locate the old Sequentix P3 assembly instructions. See, Mark actually has a kit for one of the original P3s, serial number 008, before the restyled and rackmountable case. These older versions also had a different PCB layout and BOM, so I couldn’t use the normal DIY instructions. I find this quite interesting because I’ll now have built both versions of the P3. I’m not sure how many people besides Colin Fraser, the creator of the P3 have actually gotten to see both of them in such detail.

Tonight I managed to assemble most of the easier parts of the PCBs. As can be seen above (or here full size) I fitted the sockets, resistors, caps, diodes, sockets, and other small parts. Tomorrow I hope to get to the pots, switches, LEDs, and other parts which are considerably more particular about placement. Since they are what the user actually interacts with I want to be particularly careful about them. After that it should just be a matter of completing the major component assembly, testing everything, ensuring that the firmware upgrades work as expected, getting the MemX memory expansion working, testing it all thoroughly, then sending it back. Hopefully by the end of the weekend that’s where it’ll be.

After this I may be doing some similar assembly work for another P3 (newer case style), an ASM2, and possibly some Blacet modules.

If you’d like to see all of the photos from this P3 assembly, check out this gallery: Sequentix P3 for Mark Pulver

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