Do It Yourself Usb Host Cable

[mrog100]

hello everyone,

haveing been hacking about with hardware of one kind or another for decades i thought id have a go at soldering up a gp2x host cable. reason being that allthough my breakout board works just fine its not ideal for on the go "mobile" use.

so i order a couple of EXT connectors from here http://www.artaylor.co.uk/~richard/gp2x/ to have a play with.

the EXT connectors came with a little printout of pin numbers and what they did which was a nice touch,

so the little project began

armed with trusty tools, a suitable usb donar cable and EXT connector i hack about and connect my EXT connector to the now stripped and tinned usb cable wires ..

i solder it up as follows..

+ 5v red usb cable wire----------to pin 21, +5v on the ext connector.
black usb cable wire--------------to pin 13, GND on the ext connector.
data - white usb cable wire------to pin 9, usbh1- on the ext connector.
data + green usb cable wire-----to pin 10, usbh1+ on the ext connector.

at this point i might have the beginnings of a nice and easy guide on how to make a usb host cable.. BUT

IT DOESNT WORK .. LOL

I check and recheck the soldering.. read and re read all manner of wikis.. all with no joy..

i decide my usb donar cable might not be up to the job.. so i do it all over again with another one..

all with no joy..

basiccally i get a power light from devices that are plugged into my cable.. but i cant use any of the devices..

my memory card reader lights up.. but i cant look at an sd in it... the various mice i plug in do nothing.. usb hubs show a power light but nothing works when connected to them..

all the devices iv tried are low powered things that work perfectly when connected to my un powered bob..

so can anyone shed light on whats amiss here?

so far im thinking my power wires are connected correctly.. and the usb data wires are not..

i was going to make a little how-to guide with some simple pics and diagrams.. but alas.. i cant do that if i cant even make it work!!!!!!

thanks for any possible help


matt rogers

 

[mth411]

If you have an MK1, a system before March or so, there is no power on the EXT port. It is mentioned on the site you bought the EXT adapter from. You could power the devices from some other source.

On the MK2, you can power them directly.

 

[gokalp]

First, wiki tells that Pin 21 is actually connected to 3.3V, so maybe this might create problem:
http://wiki.gp2x.org/wiki/USB_Host_BoB_Schematic

Then, if you are sure that the device is powered correctly, you should enable usb host at system menu and hid or storage drivers. After that gp2x should be able to see the devices.

 

[mrog100]

If you have an MK1, a system before March or so, there is no power on the EXT port. It is mentioned on the site you bought the EXT adapter from. You could power the devices from some other source.

On the MK2, you can power them directly.

its a mK II latest revision only a few weeks old.. so thats not the issue im afraid so far data connections rather than power connections seem the issue, as i mentioned in the opening post devices show power lights, its just they dont do anything .. lol

back to my hacking

cheers

matt rogers

First, wiki tells that Pin 21 is actually connected to 3.3V, so maybe this might create problem:
http://wiki.gp2x.org/wiki/USB_Host_BoB_Schematic

Then, if you are sure that the device is powered correctly, you should enable usb host at system menu and hid or storage drivers. After that gp2x should be able to see the devices.

yes wiki says 3.3v for pin 21, however for the latest fifth revision gp2x its 5v at pin 21.. i only know this because of the informational printout i got with the ext connectors... iv also tried powering the usb devices with their own seperate 5 volt supply..

and yes usb host is all setup correctly..

but.. it still aint workin

cheers

matt rogers

 

[gokalp]

yes wiki says 3.3v for pin 21, however for the latest fifth revision gp2x its 5v at pin 21.. i only know this because of the informational printout i got with the ext connectors... iv also tried powering the usb devices with their own seperate 5 volt supply..

and yes usb host is all setup correctly..

but.. it still aint workin

cheers

matt rogers

I see, I did not know the latest revision had that.

Also, it might sound irrelevant, but do you use a menu other than the stock menu? I have experienced problems with using usb host connectivity when I initialized it thru another menu.

Edit: Did you use the usb filtering circuit? [ http://wiki.gp2x.org/wiki/Image:Bob_usb_filter.png ]

 

[triton]

yea i was going to mention the usb filtering, i need to get on building my own bob again thanks for the reminder lol

 

[gp2xshop]

Check out http://www.spritesmods.com/?art=gp2xusb and you can see the wiring diagram for his usb mod.

I reackon try it first without power in the cable and test a powered external HDD. Just a thought?

He has also done an amazing GPS mod aswell!!

 

[thumpgun]

hope this link helps you.....http://www.hackaday.com/2006/02/12/gp2x-usb-host-mode/ :blink: