[USB hosting on the GP2X...There is light somewhere down that tunnel...maybe]

[Kaivalagi]

I originally posted a response here (http://www.dcemu.co.uk/vbulletin/showthread.php?p=80203#post80203) to peeps asking about SD wifi functionality with the GP2X, I've pasted it below again to hopefully spark some discussion on the topic in the right place! :D

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The USB feature on the GP2X is hooked into a USB 2.0 Device controller called the 'NetChip 2272' which provides slave only operation (as mentioned above) but there is also a USB 1.1 Hosting capability through the GP2X's main chip, the MMSP2 'MP2520F' developed by MagicEyes. This USB hosting IO isn't hooked up to the USB connector though :(

This means USB hosting (and therefore Wi-Fi connectivity etc etc) may not be totally ruled out if someone figures out how to provide USB hosting through the EXT port, and updates the Linux OS accordingly :) Easy to suggest, really hard to do!

I think a 'Mr Nigel Brown' is possibly going to develop and make a breakout board for the GP2X's EXT port, hopefully this will open up the possibilities a bit, check on his website here (http://www.nigelibrown.pwp.blueyonder.co.uk/gp32/index.htm) for any updates...
(no news there at the time of posting this)

Links (courtesy of the marvellous GP2X Wiki):
http://wiki.gp2x.org/wiki/NetChip_2272
http://wiki.gp2x.org/wiki/MP2520F

Also, good MP2520F architecture diagram here:
http://www.mesdigital.com/english/P...oduct_mmsp2.asp (http://www.mesdigital.com/english/Products/product_mmsp2.asp)

One think I am unclear about though, and please someone let me know, Nigel Brown maybe, is whether the EXT port provides access to all the functions of the 'MP2520F' or that it is limited in some way by the design of the PCB that the MP2520F is mounted onto? :confused: Does that make sense??

Sorry for blabbing on but I had to share what 'I THINK' I have figured out from digging around for info...:)

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Please discuss...

[yaustar]

USB hosting is possible through the standard USB port at the side of the GP2X. Our main problem is powering the damn thing and writing drivers for it as far as I remember.

edit: This information is incorrect.. IGNORE

[luke wells]

Although I have not actually looked into the feasability of this. I would assume that the solution would be to jumper a switched power point from the GP2x mainboard to the usb socket (gnd must be connected so you just need to jumper the battery + after the switch)

This would give you a 2.4 volt powered usb, which I am sure is not enough to run a usb wifi adapter.

Next step would be to make a small step up 5v switching regulator. I think there is a small surface mount MAX device that would be suitable for the sort of current we need. You would also need 2 capacitors a diode and a small inductor.

I assume there is not any space inside the case to fit this internally (I will have a look for my self ... myabe possible) if there is no space then I would make a sort of passthrough usb connector with a plug and a socket and the electronics contained inside. I would estimate this could be fitted into a 2cm cube shaped device which would mean the usb device would not stick out too far.

I may have a play about with this idea if I get time. I have all stock components apart from the step up regulator, so i will stick some on my net component order

Luke

[yaustar]

oops... I made a mistake, completely ignore my post.

[semicolo]

one could use a powerd usb hub to get rid of this usb power need (at least at first).

[yosaito]

Has it definately been proven that the usb 1.1 is wired up to the EXT port on the bottom? If not would it be possible to setup these pins as gpio and test them that way? I had a quick flick through the data sheet for the MP2520F in work but couldnt see any reference to the usb pinouts in the gpio section of the data sheet.

[Is'lan]

one could use a powerd usb hub to get rid of this usb power need (at least at first).

That's what I was thinking. I've conversed with some programming professors on my college campus concerning this, and they believe that it at least seems possible possible to connect an external hard drive to a USB slave through a USB hub and then write a device driver/firmware for the GP2X to recognize it as a storage device.

Though I wont be getting my own GP2X until May or so, I've so far been trying to learn about how I might go about this. If anyone wants to join me in this task (preferably someone who has had experience with device drivers, Linux, SDL, or at least has a GP2X), I would greatly appreciate it.

[Is'lan]

one could use a powerd usb hub to get rid of this usb power need (at least at first).

That's what I was thinking. I've conversed with some programming professors on my college campus concerning this, and they believe that it at least seems possible possible to connect an external hard drive to a USB slave through a USB hub and then write a device driver/firmware for the GP2X to recognize it as a storage device.

Though I wont be getting my own GP2X until May or so, I've so far been trying to learn about how I might go about this. If anyone wants to join me in this task (preferably someone who has had experience with device drivers, Linux, SDL, or at least has a GP2X), feel free to PM me, I would greatly appreciate it.

[semicolo]

Hum it's been some time since I studied USB, but I don't think you can hook two USB slaves together, even with an USB hub. I thought you were thinking of wiring something to the MP2520F USB 1.1 Host.

[Is'lan]

Even with custom device drivers?

[Is'lan]

Saying it's impossible just strengthens my desire! ^___^

[yosaito]

"Even with custom device drivers?"

Afaik, no its still not possible. If you write a driver for a peice of hardware the hardware has to have the functionality you require, if not you could write a software driver using some standard io pins. This would be very difficult for many reasons, especially with a protocol as complicated as usb.
What would be better is to build a connection for the usb 1.1 host connection found in the EXT port on the device. It is my belief the drivers are already available for this device but its yet to be tested, you can still use a hub to power the device.

--Edit--

Aww, by the looks of things usb host might be blown out of the water :mad:
http://www.gp32x.com/board/index.php?showtopic=25294
appears as though the eXt port pinout on the wiki is possibly inaccurate.

[Kaivalagi]

Thanks for the link, I'll make sure I keep checking for new posts. It does look like very bad news though! Damn

Someone tell me it's not true. Someone tell me they've found a way...

[Is'lan]

Have you looked at my thread on this forum concerning OTG technology? It sounds very possible, but not as good as we might like. If only someone could try it out, cuz I can't say for certain.

[yaustar]

http://wiki.gp2x.org/wiki/USB_Host

[Is'lan]

Now, is that USB 1.1 or 2.0? I don't know if I've worked with 1.1 before; would it be fast enough to play roms and movies off of?

[semicolo]

It must be usb 1.1 since it comes from the mmsp2
usb1.1 max speed = 12Mbps

will I buy a gp2x finally ?

[luke wells]

I can't believe you guys are even considering plugging a usb hub into a GP2X to get powered usb :)

Trying to get a wireless usb adapter to work on a gp2x, surely is so that you can move around and still get multiplayer / net / fileserver access without being plugged in.

I can just imagine it now, GP2X in my hand, usb cable and hub wrapped around my neck, usb hard drive in my pocket, laser printer strapped to my back hehe :)

Modifying the port to provide power either directly or through a small module is definatly the way to go

[Kaivalagi]

I don't know how people go onto talking about a USB hub? This thread started out looking at the EXT port for USB hosting, no mention of a hub at all...

Anyways, it's looking promising thanks to a post from EvilDragon. Go here for a USB Host driver, this apparently enables USB hosting on the EXT port! :)
http://www.gp32x.com/index.php?artc=2262