GameGod posted on Mar 2 2007 at 03:24 PM said:Jackd: It's hard to tell from the pictures, but it is a USB female plug on there... (You do need to plug a USB hub into that though, so you can use non-3.3V USB devices with it.)
As for a HOWTO, I don't really know what to say. I just looked at the pinouts for everything and just wired it up. I can give you all the resources I used though, and my parts list:
EXT connector pinout: http://wiki.gp2x.org/wiki/Image:Bob_ext.png
(The USB host part and the TV/Audio out part is all that I used.)
USB filter: http://wiki.gp2x.org/wiki/Image:Bob_usb_filter.png
That picture illustrates how to wire up the filter circuit for the USB host port. For some reason or another, the GP2X's USB signal is quite crappy, and this circuit smooths it out.
S-Video pinout: http://www.ghearing.com/?Gabe:ATI_All-In-W...t:SVideo_Pinout
All you should be concerned with here is the 4-pin version. The luma and chroma should be hooked up to the EXT port's VIDEO_Y and VIDEO_C pins.
- S-Video female jack (4-pin)
- Two RCA female jacks
- Two 50 pf capacitors (the filter circuit asks for 47pf, but 50pf worked fine)
- Two 33 ohm resistors
- Two 33 kilo-ohm resistors
- Samsung E810 USB cable (inside the E810 USB cable's EXT connector is a relatively easy configuration of the 24 pins for soldering. You'd think 24 pins in such a tight spot would make it ridiculously hard to solder, but the way they're spread out is quite clever, and it makes your life a lot easier. I don't think the E810 serial cable is like this, so I'd definitely recommend getting the USB one.)
I just want to point out that there's nothing new in the information that I posted above. All I did was scrape information from the wiki to construct my BOB... all the hard work in figuring out the details was done by other people before me.
Everyone seems to have ignored my how-to :wacko: , but thanks for making a great BoB, that is how to do it, and I never thought of binding the USB jack to the board like that, it could definitely work. Will that fit in a project box? If so then we can have a BoB in a case for less money than the commercial one (maybe even put a stand on top, a 1.8" HDD and batteries inside ).
I have even higher-res photos of my BoB, and I have borrowed a camera from a friend so I expect to get some nice shots of the super-mini USB termination circuit, next to my machinist's ruler it will indeed give you some sense of scale.
Now that you can see what is involved, many of you may realize that USB can be added to the current TV-Out cable for under $1 in quantity (several hundred), and demand should be high. It is literally just 4 extra wires; a very simple, very tiny circuit; and a USB jack. Now that I am getting another GP2X (been without for ~6 months or so) maybe I can cobble up a USB project board using the micro chip.
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