Car Stereo 2

Two months ago, I mentioned trying to make an interface with my stock stereo to make a car dock. Well, after a month of no luck and zero help from Honda, I went ahead and ordered one of the pre-built adapters, realizing that they weren't that expensive, and I could still build a dock that could interface with it. I went with the PIE model, as it was slightly cheaper. As soon as I got it, I popped it open. As it turns out, the biggest chip on the board is an Atmel ATMEGA168 (for those of you who don't know, that is exactly the microprocessor that Arduino uses). If someone is curious and wants to build something like this themselves, this board also uses 2 JFC4559 DUAL OP AMP chips, a DA3664 5V regulator, a 10MHz ocillator, and this interesting TI Differential Bus Transceiver [SN75176]. The datasheet I found was full of typical EE jargon, but I imagine this chip is important for interfacing with the stereo's data stream (which is probably proprietary; I couldn't find any info on it anywhere online or from Honda). I should probably also note that there is a big sticker on the device that says, "Innovations Incorporated In This Product Are Protected By U.S. Trademarks & Copyrights." Just so I'm not liable for giving out said info. There is a 4 input DIP switch inside, and according to the documentation with the device, the 4th switch controls weather the device pretends to be a CD changer or a Satellite radio. I suspect at least one of the other three allows you to use the ISP to interface with the ATMEGA. (This means, theoretically, you could reprogram the device, although what you would tell it to do, I don't know. The inputs and outputs are likely to specialized in this case, although there appear to be a number of unutilized pins on the ATMEGA, which might be usable as GPIO).

I've been still trying to get started with Arduino, but I don't seem to have as much time as I would like. Eventually, though, I'm going to want a cool iPod dock with LCD screen that will play through the car stereo, and eventually maybe even connect via Bluetooth using A2DP to my cell phone. If I progress any further, I will certainly post.

Genre Analysis

For the longest time, I have been interested in genres. I like thinking about what it is that tells you that a song is reggae and not grunge or dirty south gangsta rap or whatever. Obviously, the easiest way to do this is with math, because math is awesome! I started by thinking about several common genres, and what makes them different. I came up with several dimensional scales with which a genre or artist might fall. I may think of more (and I am open do suggestions!), but here is what I have so far:

Focus on Melody vs Focus on Rhythm

Power Metal vs Dance

Focus on Lyrics vs Focus on Instrumentation

Rap vs Classical

Natural vs. Artificial Instrumentation

Folk vs Electronic

Those are the clear cut ones. The others are a little more subjective:

Complexity

Progressive vs Punk

Aggressiveness

Blackened Death Metal vs Bubblegum Pop

The last one may be the hardest to judge, is a lot more subjective, and may be completely unnecessary. I'm looking for a broad genre that would have the same output as a different one, but haven't found one yet. As an either-or (binary system) instead of a scale, this allows for 32 different options, which even for broad genres doesn't seem like enough. I am open for thoughts on this.

Car Stereo 1

I just got an '03 Accord. The stereo is in that time period between when people had cassette players (for which you can get an aux input adapter, like this) and when everyone had mp3 players and the cars included a direct aux input.
FM transmitters suck; they are too expensive, break easily, are a pain to use, and above all, are awful quality. Surely you can plug a Research shows there are basically 2 options for installing one yourself: Blitzsafe and PIE. You won't find either for less than about $75. This is obviously a bit excessive, since there is a 14-pin output on the back of the head, which surely has at least the left/right/ground audio wires accessible.

A little more research, and I found a pinout for the connector (once I find a copy of it again, I will post it), although I have no idea if it is right. I also did a little delving into Apple's iPod cable pinout. Sure, once I had the audio wires, I could also wire up the cable to play audio and charge an iPod, but is that really enough? For docking stations, etc, Apple uses a proprietary Accessory Protocol, which is very well documented. The pinout from the car appears to use a serial connection of some kind. Wouldn't it be cool to have the car's stereo controls control the iPod? I looked at using an Arduino to handle the translation between the car and the iPod. LCD screens are surprisingly cheap; I could even get a screen to display the track info. I haven't really worked with Arduino before (though I had heard all good things) so I hadn't realized how huge the community is. Not only was there already library for controlling an 16x2 character LCD and for serial input/output, there is even a library for controlling iPods via AAP!

This removes most of the technical work of the project (especially the programming). I ordered a y-cable adapter for the 14pin output (at a freaking $20, car parts are too expensive) and the other parts necessary (Arduino, iPod breakout board, etc). I went ahead and asked Honda support for more information about the pinout on the stereo, but I am pretty confident that they will never get back to me (prove me wrong, Honda!). I am expecting to have to test the car's input/output on my own, connecting the pin to HyperTerminal or something and pressing all the buttons on my stereo. Once I have all the materials and info, I will post my results. In the meantime, I am driving around with a big hole in my dashboard.

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One last note of interest, City and Color (that's Alexisonfire's Dallas Green's side project) released his new album today, Little Hell. I am listening to it at this very moment, and am fairly impressed. Check it out.

KittyServ 3.0

So I finally have a stable server set up. It is an old Gateway that came with Win98 (and a 450MHz processor, no less!) that is now running Debian 6.0 and Apache2.2. A friend turned me on to Webmin, which screwed up my Virtual host settings, but otherwise has been a godsend. It also hosts a headless Transmission client, and when a file completes, I move it to Dropbox. This gets around the school's firewall, which frowns on p2p.

This was perfect timing, as BCAR, the alternate realities club on campus, came to me asking about starting a website for their convention April 22, KinatsuCon. Unfortunately, No one had any web design experience, and I am awful at the creative portion of web design, so I did what has become habit for me: I downloaded a CC-licensed template from spyka.net (this time it was "widget"), and got to work. Assuming we get some content, we may actually get a domain name, but for now, you can see the content-less site at kinatsucon.dyndns.org.

This also gave me the excuse to set up an FTP server (so people can keep the site updated). It was surprisingly easy to set up vsftpd, and works well.

In music-related news, we've finally got a band together (that is, we found a drummer), and can hopefully compete in the Battle of the Bands this Saturday (April 2).

Wearable Computing

So here is another mot-music related post, but it has been 2 months with nothing worth mentioning, so I might as well post something.

My next project is a wearable computer like those made popular by Steve Mann and others. While I am ashamed to admit where the inspiration came from, the more I thought about it, the more awesome it sounded.

I'm starting with a broken Acer Aspire netbook. I found a neat hand-held keyboard from this site that sells really cool shit from China for dirt cheap.

Now, I'm working on acquiring a MyVu Headset I can modify into a transparent HMD.

I made a TODO list for the project. Most of it is silly, unreasonable, etc., but some of it is actually not too difficult, including an infrared camera for night-vision.

Unrelated Circuit - 4 Bit Adding Machine

So this is a little unrelated to music, but a friend of mine today asked me how hard it would be to make a computer. Not buy a motherboard, processor, hard drive, and memory and put it together, but to actually solder components together. At first, I laughed, but when we talked about how complicated a processor alone was, I realized in theory, they aren't too complicated. Transistors basically work as electronic logic gates, were "true" is a current flowing and "false" is not. We decided something simple, like a four bit addition "processor" (not really a processor, more like an adding machine) would be theoretically possible to build, even if it was incredibly large (compared to modern processors). I quickly started drawing up schematics.

We started with truth tables for binary addition:

0101 -(binary of 5)
0110 -(binary of 6)
+____
1011 -(binary of 11)

We found that each column works like XOR, except if A and B are both 1, you have to carry a digit (like above), which makes things a little nasty. My friend stumbled upon half adder logic, which instantly un-stumped the problem. You do an XOR for the sum of A and B, but you also AND A and B and store it to C, your carry variable. Then you have to repeat the process between [the sum of A and B] and C (explaining the other "half"). Then you send that sum to the output, and carry the C to the next column.

From RabidAudio

Another EE major helped me out a little bit. He reminded me of the basic transistor circuit, which turns out to be equivalent to a NOT gate. He then showed me that if you add another transistor, it becomes a NAND gate. Wikipedia revealed a way to make XOR gates out of 4 NAND gates, and you can make AND gates by using NAND and then inverting them with NOT. The only other logic operator used is OR, which is simply a Y-connection, which means all we had left to do was substitute logic gates with transistor circuits. Below is the processor, which in total uses 76 (I think) NPN transistors, and below that is the whole circuit. Notice that it is a) very sloppy; b) has no units; c) is probably at least a little bit wrong. I found out later that there are guides for making these out there, so if you want to make one, I don't recommend using my schematic. It's here if you want it though.

From RabidAudio

From RabidAudio

Server Isues

If you've tried accessing the site recently, you probably noticed it is down. I'm having some server troubles; one's that would be easy to fix if I had direct access to it. Unfortunately, the Network on Campus disables servers, so I have to leave mine at home, and being over an hour away makes it difficult to make minor changes. I almost have a remote-access system up, but it's hard to make router settings changes if I can't reach the firewall, and trying to walk my family though it over the phone would be a nightmare.

On the other hand, pretty much all the information available on the site is also on our new Facebook page. And this blog should update to a Twitter account, which should then update to the Facebook news feed. Very messy.

EDIT 9/21: Next weekend the server will be down (not that you can tell a difference; it's been down for several weeks now while I've been away) while I switch to a significantly more secure, more reliable Linux system (I will be using Ubuntu 10.4 Server Edition, if you are curious) and away from crummy Win7.

If I can scrape together twelve hundred dollars, I can get me my dream machine, an M-Audio ProjectMix I/O. It will finalize my DAW and I can actually start professionally recording stuff.

It has a Firewire connection that works seamlessly with Logic, ProTools, etc. You move a slider in the software, and the slider on the mixer moves with it, which is one of the coolest things I have ever seen. Plus, multi-layer recording, MIDI control, and so much other cool shit.

Hopefully, I won't get too antsy and spend my savings on something else.

Site Launch

You might have noticed some changes recently, such as the redesigned logo at the top. I finally made an up-to-date website for RabidAudio. It has a real domain name, too: rabidaudio.com. I'm still trying to get my router to play nice with the server, so it may be a while until the bugs are all ironed out. If you find any, let me know. The template for the site is CC licensed from spyka.net, the same place I got the template for Music and Piracy. Obviously, even with Dreamweaver CS5 (which is amazing, by the way), I am a terrible web designer, so if you have any pointers or want to help me build a better site, shoot me an email or leave a comment (I don't get too many of those).

Effects Pedals 1.5

The loop pedal didn't really work out. Radioshack made a newer version of the device, which is surface-mount and has a different circuit, so making it loop is much more complicated. You could use a relay system, but honestly the quality of the recording is so bad that it was not worth finishing. I haven't yet had the chance to go out and get the parts for the killswitch.

In other news, IncontipleXion is considering a name change. You can vote for the new name here.

Effects Pedals 1

On my last visit to Radio Shack, I went in for a small PCB, and came out with a bag full of ICs, switches, jacks, and inspiration.

The first idea was thanks to a 555 timer. Tom Morello and Buckethead sound awesome with their killswitches, and DIY guitarists love to play with them as well. What if you didn't have to use your strumming had to use the switch? After some function crunching (I was looking for a circuit that would switch at frequencies from about .5 Hz to about 15 Hz with duty cycles from 25~75, and this was a big help), I got a design for an Auto-Killswitch. Check out the schematics here (PLEASE NOTE: I have not built it, or even tested it yet, so I cannot yet vouch for it's accuracy). The problem I'm finding now is I can't find anyone who sells 1.5M audio taper pots. Most guitar shops only have up to 1M for humbuckers. Hopefully, I will find some. I could just use 1Ms, but I would lose a lot of duty cycle range for most frequencies.

Edit (5/17/11): I just looked back at this schematic, and it is very wrong, so I removed the link. I will post a better one in the future.

The second idea is a little less original, but handy nonetheless. During a bout of wishing I had the funds for one of these beauties, I realized it wouldn't be too difficult to make a loop pedal. With some help from Instructables, I could patch together a loop pedal with 20 seconds of flash memory pretty painlessly. Just need one of these first.

Maybe now that summer is here I will have time to make at least one of these.