Category: electronics

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May 31, 2005

Click for huuuuuge…

To satisfy my desire to make something tonight, I pieced together some component video cables for a coworker. This is two sets of cables, one 18″ and the other 36″. The connectors are Neutrik NY352G’s and the cable is Belden 9259 copper shield / copper core / polyethylene foam coax. Heatshrink is random 3M stuff, and all parts were purchased from Parts Express, except the cable which is from the local Anixter location.

Off the top of my head I figure these cost about US$25 total to make plus about two hours of time. I’d put quality up there against the best commercially available component video cables.

And, it’s fun and gave me something to do.

Oh, I know the heat shrink looks like butt, but I didn’t take the time to trim the edges of it perfectly, and being adhesive-lined leaves gunk. Also, as the metal shells of the connectors heat, they keep shrinking the tubing long after I remove the heat, so some continue shrinking long after the heat gun is removed. This doesn’t matter, though, as all the solder points are dead on, and the heat shrink tubing is just there to look pretty, keep the connector together, and provide strain relief.

Yeah, I’m done babbling about cables now. Time to water the plants. Oh, that reminds me… New flower photos here and here and here. Yes, I know that the pansies are starting to look like butt. They’ve grown, but there are fewer flowers. Maybe there’ll be more flowers in a month or so. :(

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April 22, 2005

Well, I’ve determined that adding an auxiliary input to a 2005 Subaru Forester XT (well, the Subaru six-disc changer) is possible, but will be complicated. It appears that with the info and software on this page I could build just such an input.

It would then be possible to have a single cable running to the iPod’s dock connector to provide power and take a line-out. This would then be fed into the head unit and selected with (I believe) the AUX button. Or it might be whatever button selected an external CD changer…

There is also some interesting info on interfacing to Panasonic head units – essentially emulating CD changers – to be found here, but I think the first page is more along the lines of what I’m looking for.

So, I think for around US$75 or so, plus a bit of work, I could have a module which would connect into the head unit’s power and CD changer connections and happily allow my iPod to play. Then maybe another $30 or so to get everything mounted nicely…

automotive electronics moved from livejournal

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February 20, 2005

Hmm, this is kind of disappointing. I acquired the Broadcom BC5805 SSL accelerator and I’ve got it installed in a test machine. While it seems to accelerate rsa and dsa signing under OpenSSL, it doesn’t actually accelerate des and md5 stuff like I had expected.

So I did some digging, and it seems that OpenSSL is actually looking for /dev/ubscrypt and /dev/ubskey so that it can hook into the card itself and accelerate things.

I find this disappointing, because there is not a driver available for providing such things under FreeBSD, only under Linux.

computers electronics moved from livejournal

Broadcom BCM95805

February 4, 2005

Okay, so I just won an auction for a Broadcom-based hardware crypto card. Since this is supported under FreeBSD 5.2-RELEASE for accelerating crypto(4), ipsec(4), and random(4) operations, I’d like to do some benchmarking of it to see just how much it does speed things up. I’m thinking of the following for doing a before/after test of random(4):

bornslippy:~% dd if=/dev/random of=/dev/null bs=1048576 count=100
100+0 records in
100+0 records out
104857600 bytes transferred in 16.046981 secs (6534413 bytes/sec)
bornslippy:~%

I’m also looking at maybe using John the Ripper as john –test if I can determine if it actually uses crypto(9). I think that OpenSSL’s benchmark openssl test would be a good idea, because it will provide the ability to look at the effects of the card on OpenSSL, as I’m fairly certain that it does use crypto(9).

Does anyone have any other ideas as to what might be a good benchmark? I don’t think I can really test ipsec(4), but since I won’t be using it, I don’t think it’ll matter too much.

Hmm, I hope my understanding of how the driver registers itself and what it utilizes it is in line with reality…

computers electronics moved from livejournal

How To Burn Down A House

January 29, 2005

Click for more…

So yesterday I was at a friend of mine’s house when I noticed that he was throwing out an audio mixer. Asking why, I found out that someone had smoked it, then attempted to repair it. It’s current state was unknown, so I opened it up. What did I find? Something that made me worry about every single electrical repair the cuplrit may have ever done.

Why? Well, there it is right in the picture at the top… It seems that when the mixer was blown, two caps that are part of the photo preamps cooked. Well, instead of replacing them with the same parts, this “tech” chose to put together a bank of capacitors, then POT THEM WITH CANDLE WAX. Besides the fact that the bank of capacitors worked out to 50μf when the original parts were 47μf, this is so absolutely horribly dangerous. Using a potting compound that melts at a temperature around that of edible food and burns at not much higher? In a type of device which tends to get a bit warm with use? Guh.

It’s a good thing it was never turned on…

Fortunately I was able to replace the fire starters with $3 worth of proper components from Radio Shack. After fixing the cold solder joints on some jumpers that had been installed around burnt traces, I figured it was good. Well, it seems to be, and now this person can have his mixer back.

Still, I just can’t get over the idea of potting together electronics with candle wax… No matter how goth it is, it’s still a fucking stupid idea.

electronics making things moved from livejournal

Help!

October 31, 2004

To all the electronics geeks, I need help finding something. I’m looking for a 1U enclosure for a project I want to work on, and I’d like it to be plastic. I’ve seen them around online, but I can’t find a place to buy them.

Do you know where I could get one?

I’ve got a piece of gear I want to mount in an enclosure, and a plastic box would work great… And being rack-mountable would be even better. :)

So, again, what am I looking for? A 1U rack mount plastic enclosure, similar to the one seen here. (No, it doesn’t need any knobs or switches or whatever, I’ll take care of mounting those.)

Thanks!

electronics making things moved from livejournal

For Sale!

July 27, 2004

Hey everybody… I finally got some things listed on eBay today, so I thought I’d post the links here:

· VNV Nation – Advance And Follow v2 2 – Sealed New
&middot PAiA FatMan Analog Synthesizer – New – Assembled – MIDI

Oh, and yes, that’s the synth I was building a few months ago. It works great and all, but with all musical gear I acquire, I just can’t use it.

Oh, I’ve also got a Xircom PCMCIA 10/100 network card available, if anyone can use it. I’ve got no use for it, so if you’ve got a use for it, let me know.

acquired things electronics moved from livejournal

!!!

June 24, 2004

Click for more…

Well, it’s finally done. I got the PAiA FatMan finished. yay! It turns out that the problems with it were related to a bad EPROM, the bit that holds the program for the MIDI to CV conversion. I got a replacement chip, and everything was (eventually) good. There were only a few additional bumps, namely the replacement chip having it’s pins bent as hell. Fortunately it made it here, as the package it was in hadn’t been sealed. But, it’s here, assembled, and all is good. Take a look at just over a page of wonderful construction pictures here.

Or, there’s a few treats for you to listen to. Namely…

· PAiA FatMan Filter Jam (Just some random filter masturbation…)
· Eric playing the Super Mario Brothers 2 Theme Song

So, yeah. It’s done. I’m all happy about it and stuff. Now, as long as it gets good use and happy tunes are made with it, well, woo!

Also, it makes a surprising variety of sounds. You can tune it all different, have the two oscillators offset by all sorts of nifty amounts, all sorts of neat wacky filter goodness, etc.

Now, time for Luna! Woo!

electronics making things moved from livejournal music

..//..

June 23, 2004

Well, the FatMan works. I’m waiting on the replacement eprom, but in the mean time I decided to tune it up anyway. My friend Eric brought by his proper, hardware chromatic tuner so I wasn’t tuning the thing to another synth. After getting we got it all tuned, he played this:

Super Mario Brother 2 Theme Song on a PAiA FatMan

hehe…

I’ve already had it sounding all Boards of Canada-ish. This thing rocks.

electronics moved from livejournal music

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June 20, 2004

So, Friday morning, or was it Thursday night, I received a bunch of information (two massive pieces of email, in fact) from Scott at PAiA about troubleshooting a FatMan. After running down voltages and checking to be sure I didn’t have any cold solder points, I decided to swap EPROMs with another FatMan I have here. (It’s a friends and I’m looking into fixing it up.) I had tried swapping the microprocessor earlier, because I had suspected that to be a problem, but it wasn’t. This time, on suggestion from Scott at PAiA, I did, and poof, the problem was gone. So it looks like either I have a blank, or at least misburned, EPROM.

I just sent off some email to PAiA asking for another EPROM. Hopefully this one will work fine… Thus far I’m finding them to have great customer support and nice kits that are easy to assemble, but a bit of a problem packing the orders. Missing parts, unburned EPROMs, etc. They seem good about replacing bits as needed, but it still shouldn’t happen in the first place.

So, as soon as I get the new EPROM, I can get the thing tuned up and ready for use. Whee!

electronics making things moved from livejournal