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Micro-SD Card Slot Abused As VGA-Port

Soulskill posted more than 3 years ago | from the hack-it-till-it-fits dept.

Hardware Hacking 77

dvdkhlng writes "The Ben NanoNote open-source hand-held computer has often been criticized for not being very extensible hardware-wise. A community effort now starts to challenge this by shipping the so-called UBB board, which plugs into the micro-SD port, making 6 I/O lines available to hardware hackers. The most impressive use so far is this VGA port implemented by just a few resistors, with signal-generation mostly controlled by software. The guy who did this calls it an 'unexpected capability.' Schematics and source code are available under the GPL."

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77 comments

I tried (1)

SquirrelDeth (1972694) | more than 3 years ago | (#36055946)

But I couldn't fit my floppy in the Micro SD slot now its traumatized and won't work anymore.

Re:I tried (-1)

Anonymous Coward | more than 3 years ago | (#36055996)

Sounds exactly like the time I banged your sister. ^_-

Re:I tried (-1, Troll)

Anonymous Coward | more than 3 years ago | (#36056008)

tried to put your floppy in his sister and now its traumatized and wont work anymore?

Re:I tried (2, Funny)

JockTroll (996521) | more than 3 years ago | (#36056182)

Yes, it was an 8" floppy and she wasn't CP/M compatible.

Re:I tried (2, Funny)

darthdavid (835069) | more than 3 years ago | (#36057122)

When he took it out again there was a virus on it...

Re:I tried (0)

Billly Gates (198444) | more than 3 years ago | (#36058040)

"tried to put your floppy in his sister and now its traumatized and wont work anymore?"

That reminds me of a joke.

What is the difference between a woman and a computer?

A woman wont accept a 3.5 floppy

Re:I tried (1)

Coren22 (1625475) | more than 3 years ago | (#36072150)

Yeah, but it is even worse when it is a 3.5" hard disk.

Yeah, but... (0)

Anonymous Coward | more than 3 years ago | (#36055962)

Can it run Crysis?

And from left field - hey that's my drink.... (0)

Anonymous Coward | more than 3 years ago | (#36055968)

It's rare to see real out of the box hacks like this. Not a rehash with a different combination of herbs, nor completely useless.

Great-grandson of "Cheap Video Cookbook" (5, Interesting)

shoppa (464619) | more than 3 years ago | (#36055970)

Don Lancaster did a pretty good job explaining raster-scan-generated-by-cleverness-of-using-main-CPU in the Cheap Video Cookbook [amazon.com] . Back in 1978.

So slashdot is about, oh, 33 years late :-).

Re:Great-grandson of "Cheap Video Cookbook" (4, Interesting)

Anonymous Coward | more than 3 years ago | (#36056056)

The concept is as old as time. There are also lots of similar VGA out implementations for various microcontrollers, FPGAs, etc. What's new here is that the MMC controller is used to send out the pixels, which a) allows for a comparably high resolution, b) makes the operation reasonably efficient (i.e., in the future, it may even be possible to do other things in parallel), and c) hides some of the complexities of instruction timing in modern CPUs, with caches, DRAM, multiple bus masters, etc. Within the qi-hardware community, it was also a nice surprise to discover that our little Ben could actually do this.

Re:Great-grandson of "Cheap Video Cookbook" (3, Informative)

dvdkhlng (1803364) | more than 3 years ago | (#36056860)

BTW, this mailing-list post [qi-hardware.com] contains all the details about how the MMC (SDIO) controller is used here. An earlier version [qi-hardware.com] relied on doing bit-banging with the MMC lines programmed as general-purpose I/Os, but didn't even reach QVGA resolution this way.

Re:Great-grandson of "Cheap Video Cookbook" (1)

Osgeld (1900440) | more than 3 years ago | (#36057510)

just what do you think a MMC controller is really doing? its nothing special, some data lines and a clock, stick it in SPI mode with a 25MHz clock and you have most of what you need for a raster line display

Re:Great-grandson of "Cheap Video Cookbook" (0)

Anonymous Coward | more than 3 years ago | (#36058538)

First of all, SPI mode won't be enough. We need all 4 bits. (Which has the unfortunate consequence that we also can't use MMC stream mode with a basically unlimited amount of data. Stream mode is limited to a 1 bit bus, which the MMC controller painstakingly enforces.) Second, the MMC controller in the Jz4720 expects to receive a response from the device before it will send out any data. Luckily, the content of this response is not checked by the hardware and it can thus be faked.

Re:Great-grandson of "Cheap Video Cookbook" (4, Insightful)

DarkOx (621550) | more than 3 years ago | (#36056144)

Well the technique was pretty darn common in the 8 bit home computer era. So you are right in that this is not novel, but it shows its still a good method to add video to hardware that the manufacturer maybe never intended to have video out. I think this is a pretty good "News For Nerds" post even if its strictly New(s) that you can do this. I think it might be an interesting technique to apply in things like Rockbox and plug computers, as well.

Don Lancaster (5, Interesting)

Anonymous Coward | more than 3 years ago | (#36056412)

"Cheap Video Cookbook" is exactly what came to mind when heard about the VGA port (I have a Ben Nanonote and subscribe to the mailing list). I enjoyed Don Lancaster's books so much when I was a kid. He taught me not to be afraid of a soldering iron. He showed me how to disassemble software. But mostly, he explained hacker values better than anyone.

In one of his columns, he told the flute story, and it always stayed with me. I became a teacher in College ten years ago, and I always repeat this story to my students. Here it is.

"Many years ago, I was at a rock concert. The opening act was a single flute player standing solo in front of the closed stage curtains. His job was to warm up the audience for the high priced talent that was to follow. He was good. But as he went along, the musical vibes got stranger and stranger, then totally bizarre. He was playing chords on his flute. Combined with utterly unbelievable riffs. Much of the audience got impatient and bored at what seemed like a bunch of god-awful squawks. Then I happened to notice a friend beside me who had both been in and taught concert band. He was literally on the edge of his seat. He turned to me and slowly said 'You Can't Do That With a Flute.'

Of the thousands and thousands of people in the theater audience, at most only five realized they were witnessing a once-in-a-lifetime performance of the absolute mastery of a difficult and demanding instrument.

Always play for those five."

Re:Don Lancaster (1)

hedwards (940851) | more than 3 years ago | (#36056624)

5 sounds overly optimistic, I'd say at most 1 or 2.

Re:Don Lancaster (1)

am 2k (217885) | more than 3 years ago | (#36056804)

Always play for those five."

While I understand your philosophy, I don't quite see it that way. When only 1% of your audience understands what you're presenting them, you have completely failed to consider your audience when planning your performance, which is actually the most important thing.

I'm in software development, and it's the same thing: My audience doesn't care whether I created perfectly clean code for my implementation, so why should I? There has to be some other benefit to it.

It's the same in hardware marketing: The people don't care whether the computer has a CPU with 3.2GHz or 2.8GHz, so why advertise that?

Re:Don Lancaster (2)

SpeZek (970136) | more than 3 years ago | (#36056854)

The people don't care whether the computer has a CPU with 3.2GHz or 2.8GHz, so why advertise that?

Intel would care to disagree.

Re:Don Lancaster (1)

am 2k (217885) | more than 3 years ago | (#36057792)

Intel would care to disagree.

I guess that's why they nowadays give their processors fancy names like Pentium, Itanium, Core Duo and i7 instead of 80386/33, 80486/40, 8088?

Besides that, Intel's main customers are large companies like Apple and Dell. They do care about the specs, but they're not what I'd call "people".

Re:Don Lancaster (1)

Anonymous Coward | more than 3 years ago | (#36058220)

Intel changed their processor names to get better trademark protection.

Re:Don Lancaster (2)

Hal_Porter (817932) | more than 3 years ago | (#36058434)

Corporations are people too!

I have a dream where Americans are judged by their abilities, not the number of individuals that make them up. Where a Corporate American can run for President and - thanks to the votes of other Corporate Americans - win.

When President Microsoft and Vice President Haliburton take office my dream will be fulfilled.

Re:Don Lancaster (1)

am 2k (217885) | more than 3 years ago | (#36058578)

Remind me to never vote for you if you run for office :)

Re:Don Lancaster (1)

im_thatoneguy (819432) | more than 3 years ago | (#36060312)

Haha, like you'll have a choice!

Re:Don Lancaster (1)

Threni (635302) | more than 3 years ago | (#36058946)

Intel advertises on the TV all the time in the UK - an odd way to reach `large companies like Apple and Dell` if that were their aim.

Intel cares (0)

Anonymous Coward | more than 3 years ago | (#36059286)

"I guess that's why they nowadays give their processors fancy names like Pentium, Itanium, Core Duo and i7 instead of 80386/33, 80486/40, 8088?"

You can't trademark numbers. You fail.

Re:Don Lancaster (1)

im_thatoneguy (819432) | more than 3 years ago | (#36060298)

Intel would care to disagree.

No they don't. That's why my processor is called the Intel i7 920.

I don't even know what speed the i7 920 is... and I'm a huge nerd. I could look it up, but it's certainly not "advertised".

http://i598.photobucket.com/albums/tt66/plimjl/IMG_1055.jpg [photobucket.com]

Re:Don Lancaster (1)

slimjim8094 (941042) | more than 3 years ago | (#36060468)

That's a pretty nice processor, and you bought it separately so installed it yourself - assuming that's actually your box. At that level, it's almost a given that you know everything about the product by the time you walk in the door. That is, you don't walk in, say "I want that one", and spend $340 (if you did, most don't). You would've been pretty familiar with it beforehand - in the same way that a Lamborghini doesn't advertise its horsepower, since the target audience knows more about the car than you could fit on the sticker.

For the record, it's a 2.93GHz chip, but easily overclocked a good ways.

Re:Don Lancaster (2)

AJWM (19027) | more than 3 years ago | (#36057176)

My audience doesn't care whether I created perfectly clean code for my implementation, so why should I?

In your case presumably the audience can never see how clean (or not) your code is, so perhaps the point is moot. (Might be different if you're writing open source -- in which case most of the users will still never look at the code, but a few will.)

In the flute-player's case, it was all exposed for the audience. Sure, only a few appreciated it. But if you are truly skilled at something, don't you want to impress those who can appreciate it? It's like a master magician performing an old trick in a new way. Most of the audience won't know the difference -- yeah, cool trick -- but other magicians in the audience, who know what to look for or the 'usual' way to do the trick and not seeing that, they'll be impressed.

I write hard SF. I go to great effort to get details right, although I know most of my readers will neither notice nor care. As long as I entertain them, that's fine -- and it's important that the details don't get in the way of that entertainment. However there are a few who will notice, who may even do the math. They're the ones I take that extra effort for.

Re:Don Lancaster (1, Offtopic)

am 2k (217885) | more than 3 years ago | (#36057834)

I write hard SF. I go to great effort to get details right, although I know most of my readers will neither notice nor care. As long as I entertain them, that's fine -- and it's important that the details don't get in the way of that entertainment. However there are a few who will notice, who may even do the math. They're the ones I take that extra effort for.

Being a big fan of hard SF and very technically-minded myself, I appreciate your attention to detail, but be aware that you're doing that mostly for your own peace of mind. For example, there are so many faults in the Harry Potter series that somebody even wrote a whole book about that (called Harry Potter and the Methods of Rationality [fanfiction.net] ), and see what disaster it meant to J. K. Rowling's sales.

Re:Don Lancaster (1)

AJWM (19027) | more than 3 years ago | (#36130578)

A fair point, and yes, I do it because I want to -- and readers like you who do appreciate the effort. I know there are other writers, some quite prolific, who take the attitude "it's fiction, for crying out loud, just make stuff up!". Yeah, no.

If I ever get that desperate it'll be under a pen-name. ;-)

(Not that I'm above tweaking a detail for the sake of the story, but I'll try to keep that to the realm of "not proven" rather than "known false".)

Re:Don Lancaster (1)

PhunkySchtuff (208108) | more than 3 years ago | (#36058828)

Completely off-topic - but I love hard SF. I see you've got quite an extensive bibliography [alastairmayer.com] - for someone who is unfamiliar with your work, where would be a good place to start. Kindle eBooks preferred for the instant gratification factor, dead trees will be considered though.

Re:Don Lancaster (1)

AJWM (19027) | more than 3 years ago | (#36130552)

Thanks for asking. I don't want to spam Slashdot, so I'll send you an email. Or search Amazon for my author page (Alastair Mayer). All short stuff and collections so far, a couple of novels are in the works.

Re:Don Lancaster (1)

im_thatoneguy (819432) | more than 3 years ago | (#36060268)

I would say the exact opposite. Nobody cares how clean your code is--but you do.

I've seen a lot of brilliant products die because as it grew it hit the limit of what people could do with it. The products I've seen last decades aren't the same code as when they started but they did share an ease of accessibility in implementing new things.

So don't create for the 5 people in the audience. Create for yourself. Do it because it makes your life easier or excites you. Then you'll probably find an entire audience beyond 5. The flautist wasn't performing poorly--he was performing on the wrong stage.

Re:Don Lancaster (1)

AJWM (19027) | more than 3 years ago | (#36130596)

Good point, and I'm sure that flautist was performing for himself as well as the five. (And I agree with you on the software front too -- having done a couple of decades in software development myself.)

Re:Don Lancaster (1)

Billly Gates (198444) | more than 3 years ago | (#36058072)

They do depending on their needs.

Most people who just run Word and Firefox look for quality and price and maybe features like BluRay if they watch movies on a laptop. Gamers. multimedia creators, and the wealthy still look at those specs. Millions of us including most slashdotters do because we use more CPU than an average user.

If a 3.0 ghz is at the same price as a 2.8ghz then the average consumer will take notice and get the 3.0 ghz system.

Ghz is still important but the average Joe is correct that a i5 is significantly faster than a core2duo that is similiar speced.

Re:Don Lancaster (1)

mrjb (547783) | more than 3 years ago | (#36058330)

My audience doesn't care whether I created perfectly clean code for my implementation, so why should I?

Because your audience isn't just end users.
In rock band terms, the flute player doesn't only play to the radio audience, but also to fellow musicians.

Likewise, your audience isn't just your users, it's also the future maintainers of your software.

After you've made your fortune, and you are lying on a beautiful white-sand beach beneath palm trees with a long drink served by a beautiful native, give a thought to the people that now have to maintain your software.

True job satisfaction lies in the knowledge that you made life better not only for your users, but also for those who followed in your footsteps- and by setting the right example, for those who follow them.

Best of all, when you charge by the hour, you won't have to make a penny less because of it.

Re:Don Lancaster (0)

Anonymous Coward | more than 3 years ago | (#36058664)

Welcome to the reason why people think movies and music are crap. If everything you do is for the lowest common denominator then you have no reason to improve your art or take the time to make your art matter.

Re:Don Lancaster (0)

Anonymous Coward | more than 3 years ago | (#36058814)

I'm in software development, and it's the same thing: My audience doesn't care whether I created perfectly clean code for my implementation, so why should I? There has to be some other benefit to it.

If your code is more stable, smoother/faster, less resource hungry, has more insight put into the design... some will notice. Meeting a checklist of features isn't enough if there is competition. Look at those trying to sell tablets. People may not notice right away, but once they do they'll keep discovering things they like in something made by people who care deeply about the details including those that don't show.

You remind me of a cafeteria worker I once encountered. When I pointed out a piece of French toast that hadn't been completely coated in batter and had very obvious mold showing in the uncoated area, she turned it over (still in the bin, waiting for another student) and said "thanks".

Have you thought about working for NBC or Microsoft? Or perhaps a restaurant that doesn't use fresh ingredients or employees that diligently wash up after using the restroom?

While some will always be clueless, those who do immediately grasp creativeness, skill, and finer qualities will become loyal fans of something good and possibly spread the word to others who understand once shown. Of course you can always have marketing which shows fake admirers of your product.

Even if very few do seem to notice, isn't it worthwhile to feel good about what you do? Don't be the kid who craps in the pool.

Re:Don Lancaster (0)

Anonymous Coward | more than 3 years ago | (#36060316)

Always play for those five."

I'm in software development, and it's the same thing: My audience doesn't care whether I created perfectly clean code for my implementation, so why should I?

The flute story isn't about delivering a product or marketing to the correct audience, it's about living a good life.

Re:Don Lancaster (0)

aliquis (678370) | more than 3 years ago | (#36057406)

Reminds me of that movie I didn't watched but which was on the TV about a young kid which meet a group of music people (I think one grown up leader and lots of stealing children?)

Anyway he gets his hands of someones guitarr and plays by setting the strings in motion and then kinda "drumming" on them while they are vibrating (or maybe he still uses his finger tips but over the hole and not at the neck?)

Anyway, sounds pretty cool and is a creative way to use the guitarr. The movie was probably great but I didn't watched it because it sounded so boring with this musical theme.

Re:Don Lancaster (1)

ilovepi (1413699) | more than 3 years ago | (#36057604)

The movie is "August Rush", in case someone wants to look it up.

Re:Don Lancaster (3, Interesting)

Anonymous Coward | more than 3 years ago | (#36058268)

Did you read the story in the paper about Joshua Bell, one of the world's top violinists who dressed up as a bum and played the violin for day in the subway system? There was a similar moral to the story: some people took notice and went on their way, most didn't and a very few (I think the # was also 5) stopped and stayed to listen. Only one of those who stayed recognized who the musician really was.

link to story: http://www.freakonomics.com/2007/04/09/what-happens-when-a-maestro-plays-the-subway/

Re:Don Lancaster (0)

Anonymous Coward | more than 3 years ago | (#36058460)

Always play for those five."

The alternate moral is, "Most people are idiots."

Re:Great-grandson of "Cheap Video Cookbook" (1)

camperslo (704715) | more than 3 years ago | (#36059468)

If the hardware can pump out the data fast enough for a tolerable refresh rate, it might be worthwhile to make a fancier version of this VGA interface that could deliver better color depth. Take multiple clock cycles to load portions of data for each RGB pixel into something like two-stage latches, with the outputs of those driving the resistors that act as a D/A converter. 6 bits per RGB component would probably be tolerable. If one settled for 5, each 16 bits transferred would include one extra for constructing a combined V & H sync signal. The latches would be two stage to display the last full RGB pixel until the next is valid.

It seems like they were reasonably clever with the software, but didn't go very far with the hardware.

The have been some commercial products that were serious hacks over the years, like video interfaces driven through a SCSI port. Plenty is still done with Firewire.

http://www.broadcast-media.eu/2008/05/motu-v4hd-firewire-video-interface-for-mac-and-pc/ [broadcast-media.eu]

Re:Great-grandson of "Cheap Video Cookbook" (0)

Anonymous Coward | more than 3 years ago | (#36059950)

The MMC controller of the Ben seems to max out at a bus speed of 56 MHz (the nominal top speed is 20 MHz, so we're getting a reasonable margin), which is already what we need for 1024x768 at 50 Hz with four bits per pixel. You're right, at, say, VGA resolution, about twice the number of bits could be pumped out. Keeping the hardware dead simple was one of the goals of this project, both to encourage Ben owners to build their own VGA interfaces, and to demonstrate that quite interesting results can be achieved with very simple circuits.

Dithering would be another possibility to trade resolution for more colors, without extra hardware. If has its drawbacks, but some early results look promising. E.g., this image
http://en.wikipedia.org/wiki/File:Flower_bouquet20091225.JPG
becomes this:
http://downloads.qi-hardware.com/people/werner/ubb/vga/ubb-vga-bouquet-dither222.jpg

Re:Great-grandson of "Cheap Video Cookbook" (1)

RevGregory (585273) | more than 3 years ago | (#36059496)

Don Lancaster did a pretty good job explaining raster-scan-generated-by-cleverness-of-using-main-CPU in the Cheap Video Cookbook [amazon.com] . Back in 1978.

So slashdot is about, oh, 33 years late :-).

"Don Lancaster"...wow! There's a name that brings back memories of delving into 6502 machine coding in my high school years...or are they nightmares?

Down already? (0)

Anonymous Coward | more than 3 years ago | (#36055980)

Perhaps they were running the webserver off one of these too.

Re:Down already? (1)

visualight (468005) | more than 3 years ago | (#36056186)

I had it almost all the way loaded and then firefox decided to delete everything and show me a blank "the connection timed out" page instead. Brilliant.

Nice, but... (3, Insightful)

luvirini (753157) | more than 3 years ago | (#36055994)

While the GPL part is nice, and hack can be fun, the question still arises why start with such a limited platform in the first place if you have the need for more?

Re:Nice, but... (4, Insightful)

pvera (250260) | more than 3 years ago | (#36056070)

Because it opens the possibilities of other "unexpected" hacks that people can't visualize simply by looking at the available ports for a given device (not just the one in the article). If you can plug that thing into the microSD port and make it talk to VGA with 10 resistors and a bit of software, it means you can probably use microSD as a connector on other devices knowing that the connector and board are not only dirt cheap but open.

Re:Nice, but... (1)

AmberBlackCat (829689) | more than 3 years ago | (#36057830)

My brother's Android phone didn't have any video output ports. With something like this, he could use the microSD slot to connect it to the television's VGA port.

Re:Nice, but... (4, Interesting)

cfriedt (1189527) | more than 3 years ago | (#36056072)

It's often ___immeasureably__ useful to get some (any) kind of console output when porting Linux to an existing device running e.g. windows mobile 5 or 6. Take a look at HaRET [handhelds.org] . Porting is often harder than most would imagine, as some manufacturers actively use hardware obfuscation methods to prevent hacktivists from getting console access.

Try to imagine how long it would take to use LEDs or haptic feedback to iteratively check all conditions required to bring up Linux on a board without a serial port. The first thing you would probably do is try to use a hardware subsystem that was known to work and fashion a serial port out of it. This is the same concept but graphical.

Great work!

Re:Nice, but... (0)

Anonymous Coward | more than 3 years ago | (#36056124)

Your link is dead, and the website says:
Handhelds.org is undergoing renovations - The site should be active on the week of March 1st, 2011!

Re:Nice, but... (0)

Anonymous Coward | more than 3 years ago | (#36059042)

Your link is dead, and the website says:
Handhelds.org is undergoing renovations - The site should be active on the week of March 1st, 2011!

Try this [archive.org] instead.

Re:Nice, but... (0)

Bing Tsher E (943915) | more than 3 years ago | (#36056172)

It's often ___immeasureably__ useful to get some (any) kind of console output when porting Linux to an existing device running e.g. windows mobile 5 or 6.

Agreed. But hacking it to output VGA is cool, but I wouldn't call it getting console output.

Also, almost inevitably when people start work on 'porting' Linux to something, NetBSD is already running on it. Usually from the main source tree. Then someone cobbles together some sort of clunky non-standard userland onto it and calls it 'Linux.'

Re:Nice, but... (0)

Anonymous Coward | more than 3 years ago | (#36056454)

Well if it works here, why not on a plug computer or rooted android device (most of them don't have vga output)? Your market has just expanded by several million...

Why? (-1, Flamebait)

Anonymous Coward | more than 3 years ago | (#36056042)

I have been a lover of open source for years, but I have grown tired of the fractured perspectives and the dead-end projects that waste time, resources and, well, bandwidth. To put something together as an intellectual exercise, is great, but at the end of the day, there should be more of a reason to do it, if you are going to put it out into the wild. This project is one of those that ranks in the why the f^@k would anyone even care, category.

Re:Why? (5, Insightful)

cptdondo (59460) | more than 3 years ago | (#36056118)

For one it's fun. It's OK to have fun. If we only do those things that need to have a (serious) reason, we'd never have any fun. You must have gone straight from diapers to curmudgeon, without the usual goofy and fun states.

For another, this would be great for a low-cost embedded project. I can easily see this being adapted to an embedded playroom I play with.

Lastly, ti's cool.

Re:Why? (1)

houghi (78078) | more than 3 years ago | (#36057078)

So basically: All work and no play makes Jack a dull boy.

Re:Why? (2)

TheGratefulNet (143330) | more than 3 years ago | (#36056176)

its not useful to you - right now. therefore its a waste of time.

mod that parent down, please. this is useful stuff that us embedded guys can use later on, on other projects. ..not every computer is measured in ghz, jeeves old boy.

Re:Why? (2)

Bing Tsher E (943915) | more than 3 years ago | (#36056196)

Maybe they just did it so that someone like you could ask 'why.' Because I can't think of anything more satisfying than a good hack that confuses your type of person. Yeah, it ain't something you are going to use every day. As long as it befuddles the non-geeks (that's what someone who asks the question the way you phrased it is) it's cool.

Viva for 'wasting time, resources and bandwidth' even if it's someone like you, with your sort of comment, doing the wasting. I guess.

Re:Why? (3, Insightful)

LongearedBat (1665481) | more than 3 years ago | (#36056568)

why the f^@k would anyone even care

Some of us nerds care 'cos we like playing with tech. And who knows what other interesting things this might lead to, some of which might turn out to be very useful?

Re:Why? (1)

vadim_t (324782) | more than 3 years ago | (#36056622)

I like this kind of thing.

It reminds people that tech isn't magic, and that even modern high tech devices contain things that can be messed with on a budget.

From a practical standpoint, this can be useful. Maybe somebody finds that this or a similar device is just the sort of thing they need, except that it lacks the right kind of port. This kind of hack can solve the problem.

Re:Why? (4, Funny)

Jafafa Hots (580169) | more than 3 years ago | (#36056746)

Why comment on slashdot articles? What's that going to achieve?

Oh man (2)

50000BTU_barbecue (588132) | more than 3 years ago | (#36056084)

Just this morning I finished turning my VGA port into a micro-SD card slot. Now I can't submit my story to /.

Re:Oh man (0)

Anonymous Coward | more than 3 years ago | (#36056202)

Try connecting your toaster to your hdmi port and then we'll talk.

Margi Presernter - SD to VGA device (2)

hashish16 (1817982) | more than 3 years ago | (#36056132)

I don't remember the details, but this device came out a few years ago. Only difference between MircoSD and SD are a few ground pins, right? The margi probably used a ucontroller for the signal generation, now that devices are more powerful, the software implementation is now plausible.

Finally! (1)

Anonymous Coward | more than 3 years ago | (#36056138)

Micro-SD Card Slot Abused As VGA-Port

Finally! A slashdot headline I can agree with.

That's Open Hardware for you! (2)

udippel (562132) | more than 3 years ago | (#36056158)

A community effort now starts to challenge this by shipping the so-called UBB board, which plugs into the micro-SD port, making 6 I/O lines available to hardware hackers. The most impressive use so far is this VGA port implemented by just a few resistors, with signal-generation mostly controlled by software. The guy who did this calls it an 'unexpected capability.' Schematics and source code are available under the GPL."

Open Hardware; not the Open Software, is relevant in this project.

This mattered more in the pre USB-2.0 era. (1)

Animats (122034) | more than 3 years ago | (#36056520)

This was more significant in the pre-USB 2.0 era. It's now possible to get USB interfaces to almost anything. It used to be that your choices were a serial port, a parallel port, a data acquisition board, or custom hardware. Now there's usually some inexpensive USB device that will do the job.

It's hard to find low-cost devices which provide 50MHz digital in/out ports. There are lots of USB to digital I/O interface devices, but only a few can reach even 40MHz. If you don't need that much speed, though, a USB device will be simpler to deal with. And you'll be able to do something else on the main CPU while driving the I/O device.

Re:This mattered more in the pre USB-2.0 era. (1)

RyuuzakiTetsuya (195424) | more than 3 years ago | (#36056650)

For a tiny integrated machine, it matters.

If you're running it headless and need it as small as possible, having the display double as something else is huge.

Abused? (3, Insightful)

PPH (736903) | more than 3 years ago | (#36057526)

Why abused? Re-purposed sounds more accurate.

I've used a lot of 'ports' for functions not originally envisioned in their design (Rule 34 applications included) and its only abuse if you don't get permission first.

Re:Abused? (0)

Anonymous Coward | more than 3 years ago | (#36058028)

Who among us has not abused a port intended for an entirely different protocol *ough*goatse*cough*

Dual access SD card (0)

Anonymous Coward | more than 3 years ago | (#36059452)

Nice for this project. Is there a way to make this generic for other pieces of hardware?

I've always wanted an SD card which had a cable out the one end where you could view the contents of the card as it was written to be the device it was plugged into. For example, a digital camera with an SD card, takes a picture, writes to the card, and has a USB plug on other end that can download the image or video immediately to a PC.

I've seen cards with USB plugs converting the SD card into a USB card, but haven't seen anything that allows simultaneous access to the content.

The closest I've found is an eye-fi card, which uses wifi. There's also a USB stick that acts as a network interface so while it appears local, it's actually accessing a network drive, but alas, that's USB, not SD.

Available on Any microSD slot? (0)

Anonymous Coward | more than 3 years ago | (#36059854)

Will this work on any platform with a microSD slot? Or do you need a special "microSD" slot?

Re:Available on Any microSD slot? (1)

wpwrak (2132982) | more than 3 years ago | (#36084212)

This hack was tweaked until the MMC/SD controller in the SoC was happy with it. Other controllers may differ. In any case will you need the ability to switch CMD and CLK to GPIOs (without disabling the entire MMC controller) and to bit-bang them at a reasonable speed (at least a few MHz).

So it's quite platform-dependent in its current shape, but you can probably apply the same principles with other SoCs as well.

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