Usb 1.1, 2.0, Otg. What's The Diff?


Eniko

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Yeah, quick question. I know what it says in the FAQ, but in places in the board I randomly stumbled across it says you cannot in fact connect an older USB 1.1 device to the Pandora's USB host port and expect it to work. So, can you or can't you? I'd like to know since I don't have any USB 2.0 hubs lying around and I'd rather be able to make sure I have one when my Pandora gets here.

And please don't tell me to use the search function, it just ignores three letter words like "usb" "1.1" and "2.0" and "hub" and I've been trying to get a definitive answer for two hours now.
 
Eniko said:
Yeah, quick question. I know what it says in the FAQ, but in places in the board I randomly stumbled across it says you cannot in fact connect an older USB 1.1 device to the Pandora's USB host port and expect it to work. So, can you or can't you? I'd like to know since I don't have any USB 2.0 hubs lying around and I'd rather be able to make sure I have one when my Pandora gets here.

And please don't tell me to use the search function, it just ignores three letter words like "usb" "1.1" and "2.0" and "hub" and I've been trying to get a definitive answer for two hours now.
you can't connect it to the main USB port, but you can to the OTG port with the appropriate adapter. Best to just get a hub, probably, considering OTG power issues etc.
 
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is this in the faq? if it isn't could be helpful if added to the faq
 
I wonder if there are really small usb 1.1 -> 2.0 adaptors. Like, just a passthru sorta thing
 
I think you could buy a active USB extension cable and just remove the 5 m cord...
 
Tom` said:
Eniko said:
Yeah, quick question. I know what it says in the FAQ, but in places in the board I randomly stumbled across it says you cannot in fact connect an older USB 1.1 device to the Pandora's USB host port and expect it to work. So, can you or can't you? I'd like to know since I don't have any USB 2.0 hubs lying around and I'd rather be able to make sure I have one when my Pandora gets here.

And please don't tell me to use the search function, it just ignores three letter words like "usb" "1.1" and "2.0" and "hub" and I've been trying to get a definitive answer for two hours now.
you can't connect it to the main USB port, but you can to the OTG port with the appropriate adapter. Best to just get a hub, probably, considering OTG power issues etc.


What "OTG power issues"?

I'm thinking about getting a USB GPS. Most likely, that will be a USB Full Speed device, and not be compatible with the main USB port. But a GPS will expect to be powered by its USB port, and it would be rather inconvenient to use a hub, since the main times one would use a GPS are driving, riding a bicycle, or walking.
 
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DAP said:
What "OTG power issues"?

I'm thinking about getting a USB GPS. Most likely, that will be a USB Full Speed device, and not be compatible with the main USB port. But a GPS will expect to be powered by its USB port, and it would be rather inconvenient to use a hub, since the main times one would use a GPS are driving, riding a bicycle, or walking.
What I meant is that I don't have any idea whether the OTG port is powered or not. On the iriver h320, for example, you have the capability to play music from USB storage devices, but the port was unpowered (at least in US editions of the hardware, I forget how that worked exactly), so you had to build your own USB cable with a connection to a battery pack for it to work. If that would be required to use most devices with the OTG port in host mode, it's easier and probably cheaper and more convenient to just use a hub with the regular USB port.

I don't know whether this is actually the case for the Pandora - the developers have always stated that the regular USB port will be fully powered, but nothing about the OTG port.
 
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Zoppe said:
Yamara said:
Zoppe said:
is this in the faq? if it isn't could be helpful if added to the faq
I have added it to the FAQ.

thanks, now poisonedv can(and will) flame someone if they ask this question. :D (jk)
thanks for the helpful addiction

what is with you and poisonedV? He got a 1-day ban yesterday.

Go Wiki power! :rolleyes:
 
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Just out of curiosity, what is the technical reason for USB 1.1 devices not being supported?
Isn't USB 2 fully backwards compatible in the specification? And surely the controllers in the OMAP support USB 1.1?

edit for spelling ;)
 
yeah I would think that too, I mean of course no one likes that their old USB drives no longer work just because they got a whole new computer
I mean, gigabit UTP connections support things like 10megabits, so..
 
This honestly seems silly to me.

A lot of devices out there simply don't need to operate on usb 2.0. For example, a USB mouse. Manufactures could make them usb2 for very little additional cost, but they don't. Why would they; 1.1 works perfectly fine.

So what I hear you all saying, is if I want to use my keyboard/mouse combo with the pandora, I need to plug it into a usb2.0 hub? This just doesn't make sense :/
 
Ok, that makes sense if it only has an EHCI controller and no [OU]HCI controller too.
I'd never realized that EHCI was only high-speed. :)
I guess I'll be buying another USB-OTG->HOST connector. I just sold mine thinking it would be redundant...
heh.
 
I seem to recall that the OMAP has both OHCI and EHCI, but EHCI is probably for one set of ports (mapped to the USB Host socket on Pandora), and the OHCI is for another set of ports (mapped to the mini-USB connector on Pandora).

So, with a convertor, there should be little stopping you from connecting a mouse/joystick to the other socket?
 
Fortunately, there are really cheap "Universal USB" cable kits out there for extremely cheap that have the connectors that a person would need to connect a keyboard or mouse to mini USB. Here in my area of the US there is a store called Big Lots, it's like a discount department store that gets different cheap crap in every week. I'm sure there are stores like that elsewhere. Anyways, they sell this "Universal USB" cables with all the various ends for like 10$ sometimes less.

Something like this: only cheaper.
http://www.pcconnection.com/IPA/Shop/Produ...;ci_sku=7616449
 
Kimundi said:
I think you could buy a active USB extension cable and just remove the 5 m cord...
no you can't

You need a hub because it works at usb 2.0 pace and "converts" the 1.1 devices speed, the cord does absolutely nothing
 
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