Category: Projects

Tape drive VCR, part 1

One day I had this amazing idea! I was looking through the tape drives for sale, and as usual they were over $1,200 for LTO-5 or LTO-6 tape drives, which are the only generations that can match the current hard drive market. There are so many unused VHS tapes, and with the untapped potential of analog storage media, you could store digital media in these cassettes! After all, they’re just tapes! You could make… a tape drive using a VCR!

All right, I think you’ve got the sarcasm and naivety of my thought process. I mean, if you think about it only for a few seconds, it’s just silly humor. But when it remains within your mind for days on end, wondering whether or not it truly is possible, you feel as if the only way to find out is to try it yourself.

Let’s take a closer look at this incredulous idea. The first and only popular stab at this was ArVid. It was basically this Russian ISA card that ran composite video to your VCR, and that was it. It could store data at a speed up to 325 kbps, and with some simple math we come up to almost exactly 2 GB on an E-180. And you know what, a lot of people said “yeah, I guess that’s reasonable,” and they stopped there.

But there are some huge limitations to ArVid, that could have allowed it to increase in data retention. First, it has only two symbols: luma on and off (!!!), which already makes the storage incredibly inefficient! It uses some Hamming for ECC but that’s about it, according to Wikipedia. Now, I’m no expert here on signal processing (just started seriously reading about this an hour or two ago), but with QPSK or QAM, we can make it significantly more efficient. So, screw ArVid.

We also don’t need an additional card to bring the analog data over to the VCR. We can use the sound “card” that is already built into the motherboard to produce the analog signals we need, and at an acceptable sample rate too (while “sample rate” doesn’t exist when we’re talking about pure analog signals, we do still need to convert digital signals over to analog, but the sound card can only support up to 96 kHz or 192 kHz, thereby limiting our symbol rate). A separate sound card might still be convenient, however, given that this method may hinder a user’s ability to use sound at all (or the user may accidentally trigger a system sound that interferes with the data throughput).

So, how much data exactly do we think a VHS can carry? I think that in a perfect world with an ideal design, it will be somewhere between 80-160 GB. However, formal calculations based on the modulation to be used will be required in order to prove this, so I will not talk much about it.

Instead, I’ll discuss the practicality of this design. Yes, you could hack a remote control and stick it to the VCR, and that would be the interface for communication. Haha! But to be honest, I’m not really willing to destroy my VCR and remote just to figure out how well this is going to work. The solution, then, becomes fairly clear: just have the user be instructed on what to do. The user would note where a datum is stored and all he would do is just move the head right before it and hit “read” right before the data is reached. The signal would be aligned and processed perfectly.

Alternatively, we can tell the user to “initialize” the VHS by having the software sprinkle position markers across the tape. They don’t have to be exact placements, but they give the software an idea of what spaces have been consumed and where to go based on the last read position marker, assuming that the software is tracking where data has been stored in some sort of external master file table. This can then be turned into simple “rewind for about 20 seconds” commands given to the user. The user would play back a little bit, which would allow the software to give feedback on how close they are to to the data (and if actual data is being played back, then this should be detected and the user should be instructed to go back to the beginning of the data).

I’ve been taking a look at GNU Radio and I think this should give me a fair estimation of what modulation method(s) to use, and how much noise is expected. We’re dealing with VHS, which is great, because the expected noise is extremely low.

Soldering

The big problem of soldering is the resources. If you don’t have the right materials, the right solder and the right flux, you’re going to end up botching the whole thing like I did.

View post on imgur.com

It was fairly obvious that I was going to mess up. But hey, you know what they say: if you must fail, fail spectacularly!

Oh well, eventually I’ll have this 20×4 LCD set up and wired to the Elegoo Uno R3 (an Arduino/Genuino Uno clone). Unfortunately, I don’t have those easy-to-solder pins, which is why I have to do this ugly hack soldering the cables in. Hopefully the LCD doesn’t turn out to be destroyed by the heat.

The hackathon

The hackathon was okay. There were some regrettable moments and some unforgettable ones.

When I arrived there, I was still pretty miffed that my friends had ostracized me from their group. I came in with the “I’m-scared-of-tall-white-people-with-glasses-and-braces” look, but to be honest, looks turned out to be deceiving when the final products appeared.

I saw some kids from my summer engineering program, at least the ones that mattered. There was a noticeably smaller amount of kids than were expected, but this turned out to be quite advantageous.

As with any group project, I was the mastermind, and everyone else just sat and watched me do all the work. More specifically, they played League of Legends for hours on end. That morning I did not have an idea for a project, but before I came, I suddenly recalled my need of an all-encompassing cloud storage solution, so I decided to call it UltronCloud. I mean it’s not ever going to be finished, so just give it some joke name.

The environment was excellent; this was the college my brother goes to. It’s private but the tuition turned out to cost less than that of a public university, and needless to say, it seems that every penny of it was spent wisely on the infrastructure and architecture. I got a huge-screen television all for myself, so I was able to use the television as my primary monitor, which made it very easy for my eyes as the night progressed.

The hackathon was great, or rather should have been great. But I think I did not take advantage of the opportunities; there were mentors who were teaching how to develop for mobile platforms. I also didn’t take as many breaks as I should have; I strained myself in order to squeeze every hour of the venue, so I didn’t have as much fun with other kids. On top of that, the challenges I was facing when making the project were serious yet to a ridiculous extent. Some problems took hours to be solved, only to be met with yet another problem.

This following section is part of an issue I made on the repository of the library I used, because the following morning, I was so mad that I had wasted all this time for nothing. Once again, I hold nothing against the developer of the library:

Literally every step of the way has been riddled with bugs and other quirks and undefined behavior, even when following the instructions to the letter and trying it on two different Windows 7 x64 machines. Needless to say that I wasted my time trying to make a frontend out of this library. Maybe you can figure out whether the library hates me or if it’s just that unstable.

The first problem was when DokanCloudFS failed to load assemblies when I set the build configuration to NuGet-Signed. If I tried cleaning the build, it would still error out. If I tried changing the build config back to regular NuGet, yet again it would throw the exact same exception. The solution was to nuke the entire project, keep it in the default configuration and never touch it again. This alone cost me a few hours to figure out.

And alas, very shortly later, more problems arose. My mounted Google Drive appeared as a drive, but all interactivity with it was completely blocked, thanks to a vague exception thrown repeatedly as shown in the console:

Exception thrown: 'Google.GoogleApiException' in mscorlib.dll
...
Exception thrown: 'Google.GoogleApiException' in Google.Apis.dll
Exception thrown: 'System.IO.InvalidDataException' in SharpAESCrypt.dll
...
Absolutely no stack trace and Visual Studio did not even bother to break.

And this was after I had compiled CloudFS, put in secret keys for GDrive, copied the output DLLs to the DokanCloudFS Library folder, and assured that it had access to the Drive API by turning it on in the console, and waited a few minutes for it to “enable”.

So I said, screw it! Let’s use OneDrive instead, thinking that somehow it would ease my pain. Nope. Same spiel. Except Microsoft was taking me to some OAuth2 auth link that would just take me to a blank page. After a bit of research I found out that I had to add “mobile” as a platform in order for me to even have an OAuth2 login page. Okay, so when it asks me, “Let this app access your info?” and the usual permissions and I click “yes,” ….it just opens another browser window to do the exact same thing. I click yes again, and the window reappears ad infinitum. And instead of the `GoogleApiException` I get a `System.Security.Authentication.AuthenticationException in mscorlib.dll` along with a `System.AggregateException` which VS *should* be breaking to tell me about, but it’s not doing squat.

By this time I’m forgetting about even running the DokanCloudFS.Mounter example and instead just building hacks to bridge the frontend with the library, using the mounter program as an example because there’s absolutely no documentation that comes with it.

And as of the time of the writing of this issue, I’ve spent sixteen hours trying to get all this to work just to make a frontend that will mount OneDrive, Google Drive, etc. in unison.

I racked my brains so hard that instead of pulling the all-nighter as I had intended to, I decided to sleep for three hours. I didn’t bring a pillow nor a sleeping bag, so I was in for a really nice sleeping experience. Thank the lady who showed me where the cot was in the nice, dark, quiet room; all the couches were taken. So between the hours of 3 AM and 6 AM, I decided to rest and try to figure out what to do with the project. Now, the resting period was important because when I woke up (I think I only achieved REM sleep for a few minutes), I did not feel disillusioned as I usually am when I am sleep deprived (the reason for this is that the image of sunset is still ingrained in my brain, so it gives the impression that it was a very short night and that I will have to sleep during daytime hours to compensate for this).

When I woke up, I returned to my workspace. My teammates were still playing League as they were before I went to sleep, and I sat down and looked at Visual Studio. I tried to begin hacking together some sort of interface to figure out if any functionality is possible, but it was futile. By 10 AM, I simple gave up. I failed.

I had really been looking forward to the hackathon, and I met quite a few people there. But I was not met with a stroke of luck, and the hackathon was not as enjoyable as it could have. If I went back in time, I could have done all the right decisions: convince my friend to let me in the team, bring a pillow and a surface to sleep on, actually go to one of the Android workshops, talk with the head of the hackathon, etc.

But alas, the result would have been the same regardless of anything. The judges delivered some rather questionable decisions in terms of which project was “better”; despite my utter failure, I placed third in “best software hack,” and my friend’s team, who had put all their efforts on a robotic hand, did not seem to place at all in the “best hardware hack.” What? At least there was an “everyone’s a winner” attitude which is a nice way to end a hackathon. No massive prizes for winners, like a graphics card or anything like that.

I don’t really know what to do now though; I left the hackathon with an incomplete satisfaction. What can I do instead: order parts for the electric bicycle? Compensate by trying to invite my friends to do something similar? Or just work on the school stuff I’m supposed to finish by the first day of school?

Ugh. I had felt during the hackathon that this was the beginning of my demise; that this was a glimpse of my condemnation; that I was no match for anyone around me in terms of college admissions. It’s not true. But one question still remains: what am I to do now?

Zero-gravity soccer – part 1

A few weeks ago I was assigned a final project. The final project could be anything as long as it’s written in Python. So I chose to make a game.

And so the mad scramble began. Actually, it wasn’t really a mad scramble at all. I took my time with the code, working on it only when I was able to do so. And so without the distractions of my brother, I was able to knock out 8 hours of coding today, which equates to 570 lines to check into source control.

Python is an incredibly addictive language. I thought it was just some simple language for kids; boy, was I wrong. It is a language of elegance, of minimalism. It makes Java look like a rusty pipe under a sink (which it is, for the most part). Say goodbye to curly braces and excess if statements. And bugs are incredibly easy to find, even without an IDE, if there are any in your code.

Python does have its shortcomings, however. Its object-oriented design isn’t exactly something familiar, and the mechanics of it are definitely not explicit. Still, it allows for multiple inheritance along with a degree of control you could never have with Java. In Java, you had to make a rigid model of the class before actually implementing it, and changing constructors around leads to problems down the line fairly quickly. In Python, however, you can build the implementation first, and then make an object encasing that behavior. It is purpose-driven rather than enterprise-driven, and so it works extremely well for small projects.

This is what I’ve been able to accomplish so far. I have until the 20th to “ship” the project, if you will, and I’m quite satisfied with the progress so far. I estimate it will only take 500-750 more lines to bring it to a playable state, but then again, I cannot make a fair estimate of line count because it’s not really what matters. I need to implement network, HUD, and some game-specific behaviors like grabbing the ball and throwing it to the goal.

I shall press forward…

The AoS bot that I originally wanted to make

crossposted from the BnS forums:

A few years back I thought of exactly this, a decent bot. At that time I did not have the experience to actually create AI but I started slowly working on a client implementation in JavaScript anyway. My imagination ran aloose: if I could make excellent AI, I could start a clan of “noobs”, watch everybody get rekt in League, and then reveal how I did it. Built-in inaccuracies and limitations would prevent any detection of ESP, because the AI would hypothetically only be able to view the map and within its line of sight, perform some limited communication, and have a reasonable (and adjustable) hit/miss percentage. The bot could also build prefabs, and other bots could join in or defend as they are building.

I thought about a design for such a system of bots for a very long time, and I looked at some dumb bots some people around here made in Python. But I wanted the “unauthorized” approach, so I was not inclined to create a serverside script. I wanted a clientside approach that would be controlled by the bot master’s computer, so that I could simply and inconspicuously deploy three or four well balanced bots on a server. The problem, of course, is that there is a limit for clients per IP address.

The problem in the holistic sense when I envisioned this concept was not the algorithmic portion as it was the implementation and the time that it would take to complete this undertaking, which I repeatedly underestimated. Moreover, I was not familiar with three-dimensional A* or machine learning concepts. I was eager to learn them, which is really what matters. But time always turned out to be the greatest deciding factor in all of this. My time was always fragmented; 15 minutes doing this, 15 minutes doing that, rather than a solid slot of 3 hours of project time. And due to school, my free time varies from 3 nice hours of relaxation to absolutely nothing.

Many of you think that this is my excuse all the time for not being able to do anything. But it’s true, and so my disposition to commit to things has fallen. That’s why I never carried out the whole bot thing in the first place. I just did the backend and that was it. You want to pressure me into doing it for that AoS of the Future project, fine. You want to pressure me into doing it so I can fill your servers with future-proofness, fine. You want me to do it for the betterment of all your little FPS projects, fine.

Suffice to say, a well scripted bot would be perfect in imperfection. But I am not one to do it.

My faith in humanity has been restored

Some-faith-in-humanity-has-been-restored

I don’t know how, I don’t know when, but I feel better now. Not sure for how long I’ll feel better, but certainly I feel somewhat more confident of my abilities now.

That said…

LameBoy

LameBoy debuggerIt’s going okay. Right now it’s clocking at about 5.5k lines of code, so evidently still in its infancy, but we are making progress fairly quickly. I had to break everything so that I could add a layer of abstraction. It’s just a matter of cleaning up Denton’s crappy code and future-proofing it.

(more…)

Amazing find!

So I reluctantly got an older version of Pokemon Type Wild and started playing it. I noticed that the music was sounding a bit funkier…. and I found that the music for the older versions for Type Wild were MIDIs!

I find MIDI to be a highly flexible format (you can make the instruments 8-bit, mash it up, …); as such, I cherish MIDI and especially VGMusic for its massive library of MIDIified (and original) game music.

This is a lucky discovery because then I can remake the MIDIs into nicer quality audio files for those who don’t have 500 MB worth of instrument data.