$20 Usb Cable Plans/parts List/instructions.

[nubie]

I was considering making a parts list, and maybe instructions, so that people could use the USB host for under $20 or so in parts.

So, the question is: Can we make a USB cable for portability and simplicity's sake that will satisfy the needs of 99.9 percent of the users by only having USB and TV-Out and nothing else.

I am 100% sure it can be mass-produced (as an "extended TV-Cable With USB"), for less than $20.

All we need is a small circuit board with this filter (below) and a 5 volt upconverting chip/circuit, it could fit under the shell of the TV EXT cable as it is right now. The question is what will the cost be to run off a bunch of these boards with 4~5 surface mount components on them? And is anyone willing to make this? A fortune could be made, $20 for this cable would sell like hot-cakes.

I found this, a chip that will do the USB filtering circuit displayed in the wiki (and more, like ESD filtering):

http://www1.mouser.com/index.cfm?handler=d...roductid=954537

It is priced very cheaply:

quantity......Price each
1:..............$ 0.380
25:............$ 0.300
100:..........$ 0.270
500:..........$ 0.240
1,000:.......$ 0.210
2,000:.......$ 0.195

Mini-Rant: As you may notice these are $0.20 apeice in a 2,000 lot. Why didn't GPH just terminate the damn thing with a tiny tiny 6 leg IC?? I have no idea, I also have no hope of communicating to them their infinite blunder because they don't speak english. They re-designed the board already, it now has 5 volts coming out of the multi-purpose DC-DC convertor chip (will make 6 custom, settable voltages), and the joystick is rotated. WHY COULDN'T THEY ADD A 20 CENT PIECE AND RUN 5 VOLTS OUT????

The answer is simple in my mind, they want to charge you $75 for USB functionality (maybe more, we haven't even seen a user-friendly version with a case yet), while you are paying for:

* $25 12 volt Power Supply (why Damnit, the USB spec Is FIVE VOLTS, 5 volts, AKA NOT 12 volts)

* Parallel DB-25 Jtag (most users who want this will have a parrallel to Jtag already, you are cheating them, just put standard 2x20 Jtag header onboard.)

* Serial debugging (mostly only useful if you need to Jtag, or are programming without the Linux Kernel, which passes the terminal to USB since firmware 2.0?? unsure which firmware it started in.)

USB 1.1 hub (got one for $8 at staples, unpowered. Radio shack has powerd ones for $11 and $14, WITH the (5 Volt) power supply included).

Now that I am done explaining why the commercial offering is Shite, here is my plan:

I can draw up instructions on how to build my circuit, help lay plans for a double or single-sided board that can be added to the existing TV-Cable for $10 (by a user with the proper TV-Cable with all the pins, or at the factory). Or just get some input on how the scene and hardware modders feel about this.

If designed correctly we could make the board multi-purpose, or make a version without the 5-volts power circuit could be put inside to terminate a hack like the hackaday one( Instructions), or a mod could be performed by ED on units leaving his shop. (The hope is that we can get GPH to design a version 3 PCB with a USB port already in that location, or another location, as long as it isn't sticking out the side).

Post here what you think and I will see how everyone feels about this kind of project, I hope that if we can design a good circuit (I don't personally have an electrical engineering degree), we could convince a distributor to produce these.

An interesting thing to note is that it will cost about $2-3 for the circuit without the power supplying part, thus a "hackaday-like" mod would likely cost the same amount as a cable including an expensive DC-DC convertor chip. If offered as a service (or an option with a new GP2X), it could be very beneficial (monetarily and in making the scene more tightly-knit) for the distributors and the consumers.

 

[yalborap]

Definitely sounds like a good idea. I know I need a USB cable but don't have the skills to make my own, and I'm sure a lot of others are in the same situation. This would be VERY useful, especially if it's available for US dollars, what with the current source for things like this being UK-based.

 

[chiefsmurph]

Thats exactly the same reason I don't have one. Shipping from the UK is such a pain.

It also seems stupid to have to pay for the developer's break out box when its so expensive and ugly.

 

[nubie]

Definitely sounds like a good idea. I know I need a USB cable but don't have the skills to make my own, and I'm sure a lot of others are in the same situation. This would be VERY useful, especially if it's available for US dollars, what with the current source for things like this being UK-based.

I found this, it is 20£ : http://www.artaylor.co.uk/~richard/gp2x/

notice this too:

Why only rev.2?
The REV.2 GP2x supplies 5V out of the EXT port, so it is no longer required to have a 3.3v to 5v DC-DC convertor.

That is most interesting, My MK2 wasn't supplying the 5 volts, only 3.3, anyone got a pinout of the MK2 EXT that is usable?

My idea still stands, if the proper distributors would offer this cable with the TV-Out, or as a modification, they could make a killing.

@ ED, or Craig, what are your thoughts? Are you planning on offering a 15£ or $25 option to the TV-Out cable, or a modification? Or anything? I know it would require a bit of outlay, maybe you could gauge customer response. Even $30 or 20£ is better than the alternatives. AND more portable by far.

 

[i_am_a_noob]

Snap, i just realised i don't have an MK2, missed it by a week(birthday preasent(didn't have any say in it)).

 

[manicresin]

i would like to have instuctions on how to make a usb cable, i think ive seen some out there but they where not the easiest to follow, i want to make a short cable/connector for a hard drive add-on that would connect to the back of the gp2x using a 1.8' laptop drive

 

[Epicenter]

I still like most the idea I heard of to build a custom GP2X backplate that houses USB ports amid other things; e.g. TV output connectors. Anyone with basic soldering skills could install one if they're careful.

 

[nubie]

I still like most the idea I heard of to build a custom GP2X backplate that houses USB ports amid other things; e.g. TV output connectors. Anyone with basic soldering skills could install one if they're careful.

Agreed, but if this could just be added to the existing TV-Out as another dongle for a reasonable price, then why not?

In theory it is not all that different from the backplate, which could take a few forms, either one with a hub, and external. Or my personal choice would be a custom PCB that had a 3.5mm phono A/V cable like a camcorder, and USB, that would be an internal mod like the hackaday thing, keeping it all internal would definitely add to the appeal for me.

On the subject of step-by-step instructions, with photos, I think it might be wisest to leave all the information as it is, for a few good reasons.

1. artaylor is selling an EXT to USB cable already.

2. All the information is there, if you can't break down the information, please take a course, or read a book, on electronics.

This circuit really is the simplest thing to do, it is two resistors that each signal wire goes through, and then two more resistors to terminate the signal to ground. And then it is just a couple tantalum capacitors to smooth out the voltage changes. And as mentioned, there is a ready-made $0.38 piece that does all of that, just wire it in.

I just don't own a GP2X and don't feel like trying to teach people basic electronics over the internet right now, there wasn't enough interest in it anyway, sorry.

I haven't yet heard from craigix or ED on how they feel about pestering GPH for the USB on the TV cable idea, or doing it themselves (come on guys, it is a 38 cent chip, if the MK2 makes 5 volts you are home).

I guess you who want to can PM or email them about what they feel on the matter, please be courteous and civil, they don't need to be pestered. Make sure your subject line includes USB and TV Dongle, not something cryptic.

 

[Epicenter]

Mm, I'd still lean toward something integrated or you have a nasty bundle of wires hanging off your GP2X still. That's not very good for portability at all. I mean, an EXT to USB cord adapter is fine as I can hook it up to my 3 port hub and attach that to a power brick (it has a jack for one.) But it's not simple or compact at all.