Usb Hub

[buntz]

So i made a cable to connect to the EXT port and I have it soldered to a header and connected to a breadboard right now. USB host works fine as long as I plug the mouse into the port itself. If I try to connect a usb hub, it wont work even after a reboot (does the gp2x no support hot swapping? Thought that was almost the deffinaition of USB). I get my power for the gp2x and the usb from a hacked ATX power supply and i know that works, it just seems as if the gp2x doesnt like the hub for some reason. Has anyone connected a hub succesfully? I know there is one on the commercially avalible interface board, so what gives?

 

[BradN]

I'm assuming you have the filter components on the breadboard, but if you don't, that would be good to add.

 

[buntz]

I'm assuming you have the filter components on the breadboard, but if you don't, that would be good to add.

I dont actually. I figured that the mouse worked fine with out the filter, and I took the hub apart and i can see filtering resistors and caps on the board, but what I really want to know is do i need software to make the hub work or will the gp2x detect it by itself. If you dont need and drivers, then i'll add those filtering compnents to the circut.

 

[BradN]

Any drivers needed for a hub should be built in - in fact I don't think it's possible to not include them, since hubs can even be used as part of motherboard hardware, etc.

Keep in mind the mouse runs at a lower signalling rate (1.5mbit/sec vs 11?) so it may work alright without the filter.

 

[triton]

my question is do the resistors have to be the exact resistance specified or can they be different, if so what kind of range?

 

[BradN]

If you've got an ohm meter, you could test ones you have and try to pick stuff within 10% (that's a typical tolerance value anyway, though rated tolerance can range from I think 2% to 20%). If you put resistors in series, the resistance adds, so this might be useful if you don't have something exact, but don't get too carried away.

 

[buntz]

Keep in mind the mouse runs at a lower signalling rate (1.5mbit/sec vs 11?) so it may work alright without the filter.

Yeah good call. Wasn't even thinking about that.

[edit] Yeah deffinately needed the filter circut. I used the specified resistors, but used 22pF caps instead cause thats all i had around.