Usb Otg Adapters


P

Prestidigitator

Still Fresh
Joined
Oct 19, 2008
Messages
10
I read about the solution to using USB 1.1 devices on the Pandora. At first, it was as simple as just connect it to the USB OTG port. It didn't prove to be that simple because I've had a lot of trouble shopping for exactly the adapters I need.

I tried learning about USB OTG and I found there's USB micro A, USB micro B, and even USB micro AB! This vendor has an adapter for all three types.
http://www.retractablecables.com/newsearch...rsearch=popular

I know that once connecting the USB micro A or micro B connector to the Pandora OTG port that I'll need USB gender changer before I can connect my USB 1.1 mouse, for instance. But, does it matter whether it's micro A or micro B?

Maybe it's best if someone can answer like this:
1. Is there a really a difference between USB micro A and micro B?
2. If so, what would be the different uses on the Pandora?
3. Is there any use for the micro AB female to USB A male adapter?

Trying to create the shopping cart on Amazon was a nightmare. I couldn't get these adapters from the same vendor and wind up paying shipping from one company on top of shipping from another. Has anyone created an optimal Amazon or Buy.com shopping cart where you only pay shipping one time? It would include a USB gender changer, and the right USB micro adapters according to the answers to the above questions.
 
Last edited by a moderator:
Why bother with a gender changer? Thats the incorrect way of doing it, and it's doubtful it would work, as OTG USB requires a different configuration than the kind of cable you would use to connect to your PC.

How about something like this:

www.amazon.co.uk/OTG-Cable-Adapter-plug-Socket/dp/B000EORX7U

31AG3DV7FKL._SL500_AA280_.jpg
 
Last edited by a moderator:
USB is supposed to be really easy. It works like this:

A is for upstream (host PC, Pandora, hub out-ports)
B is for downstream (hub in-port, devices like mouse, mass storage etc.)

These are available in standard, mini and micro sizes, though mini versions have recently been forbidden for new devices (except mini-B ).

OTG is special: It is for devices that sometimes work as a device and sometimes as a host. While the Pandora cannot fulfill the OTG standard, it does have this functionality. Thus it needs a receptable to take both A and B plugs, an AB receptable. These exist in mini and micro sizes and the mini ones are not allowed anymore for new devices. I'm not entirely sure which kind of connector the Pandora has, though.

In USB, there should never be the need to change gender. A cable has two male ends, one A end and one B end.

What you need to connect your mouse, or any USB device with a standard male plug, is a standard A receptable to micro A plug adapter.

Here is the announcement about mini A and mini AB now being forbidden and it includes a list of all currently allowed cables:
CODE
http://www.usb.org/developers/Deprecation_Announcement_052507.pdf


Of course, there is an infinite number of non-standard USB cables and adapters...
 
Last edited by a moderator:
Oh my god every time USB comes up I get confused as hell. I know there is an issue with it, but I don't know why: why can't usb 1.1 use the usb 2.0 port? And what is the mini usb for
 
Last edited by a moderator:
USB 2.0 hosts aren't automatically backwards-compatible; they require an additional chip onboard to convert lo/hi-speed (1.x) signals into full-speed (2.0). IIRC 1.1 compatibility _is_ part of the USB standard, but we don't have the necessary components on board, so a backwards-compatible 2.0 hub is required. The mini-USB OTG port can charge the pandora, but it's also compatible with whatever 1.x devices you plug into it. It might not be able to supply as much power as the full-size port, but I forget the exact numbers.
 
Last edited by a moderator:
'typs lik dis' said:
The mini-USB OTG port can charge the pandora, but it's also compatible with whatever 1.x devices you plug into it. It might not be able to supply as much power as the full-size port, but I forget the exact numbers.

Host port - 500mA
OTG port - 100mA
Click to expand...
 
Last edited by a moderator:
Squidge:
About your product recommendation: The connector is described as mini and it looks to be so. I'm confused because I thought all OTG implied micro connectors. Is the OTG port on the Pandora mini or micro?
 
Last edited by a moderator:
The last time I heard, it was mini. I also seem to be surrounded by devices with mini connectors, but not a single one with Micro. I have lots of mini cables too, so I don't really care if I lose one. Even though USB.org has deprecated the mini, I still prefer it due to its larger size, and it seems a lot of other people do too.

Micro just doesn't give me the same confidence.
 
Last edited by a moderator:
Micro is stupid. If you want proper OTG on mini, though, you need to tie pin 5 to ground.

Had to do so for my N800 to switch modes, turns out a lot of other OTG devices need that to work. :(
 
Last edited by a moderator:
It's Mini A-B.

www.gp32x.de/board/index.php?showtopic=43354&st=40&p=634353&#entry634353


[edit] Just went googling to clarify this for myself - the Mini A-B is a universal socket that will accept Mini A or Mini B plugs. Sweet.

Source: www.accesscomms.com.au/reference/usb.htm

(Pretty good USB reference page, but lacks any mention of OTG.)
 
Last edited by a moderator:
'palmertech' said:
Micro is stupid. If you want proper OTG on mini, though, you need to tie pin 5 to ground.

Had to do so for my N800 to switch modes, turns out a lot of other OTG devices need that to work. :(
Click to expand...
You can also buy an USB mini A -> USB mini B cable (to connect to most hubs and "small" devices), USB mini A -> USB B (to connect to something like a printer) or USB mini A male -> USB A female (to allow you to connect to most "common" stuff with a builtin cable like mice etc.)

they all include the proper grounding that tells pandora to work as host
 
Last edited by a moderator:
'valhalla' said:
You can also buy an USB mini A -> USB mini B cable (to connect to most hubs and "small" devices), USB mini A -> USB B (to connect to something like a printer) or USB mini A male -> USB A female (to allow you to connect to most "common" stuff with a builtin cable like mice etc.)
Click to expand...
Really? I've only seen the third type, and even they were insanely rare until recently (of course, now that they're readily available, the bloody USB standards group deprecates it. F***ers.)
 
Last edited by a moderator:
'Squidge' said:
Why bother with a gender changer? Thats the incorrect way of doing it, and it's doubtful it would work, as OTG USB requires a different configuration than the kind of cable you would use to connect to your PC.

How about something like this:

www.amazon.co.uk/OTG-Cable-Adapter-plug-Socket/dp/B000EORX7U

31AG3DV7FKL._SL500_AA280_.jpg
Click to expand...
So for host mode does pin 5 have to be tied to ground? And does this adapter do that? Or is it the other way round (for slave mode pin 5 must be tied to ground). I just want to have 2 cables - one like the one squidge has pictured above, and one to plug into my desktop.

Is the USB host port a standard size socket? And does that support USB 1.1 with/without a hub?
 
Last edited by a moderator:
It's a device socket by default. To turn it into a host socket, you will have to configure it one way or the other. The typical way of doing this is by grounding pin 5, but we don't know if this is how the Pandora will work (It could be a menu option, for example).
 
Last edited by a moderator:
I took a look at that document depreciating mini-A connectors. This makes a lot of sense.
Currently there are very few devices with mini-A connectors on them (mostly USB OTG devices with mini-AB connectors, and there are very few of those).
By eliminating mini-A connectors, they reduce the number of different types of cables required from 9 to 6, since formerly there were three sizes of A (A, mini-A, and micro-A), and three sizes of B (B, mini-B, micro-B ). They have not depreciated the mini-B connector, because there are very many portable devices using the mini-B connector.

This puts the Pandora in an interesting position. The mini-AB connector that they use for USB OTG has been depreciated, and the USB A connector they use is not standards complaint. On top of that, it appears that this document states that if you have a USB OTG micro-AB port on your device, you are not allowed to have any other USB ports on your device.
I guess we won't be seeing any USB logos anywhere on the Pandora. :blink:


Edited to eliminate accidental smiley. (Unfortunately, this also appears to have broken the intentional smiley)
 
Last edited by a moderator:
Ok. To summarize:

I ought to at least look for a male mini A to usb A socket because the A plug on the mini end means the pandora will act as a host.

A male mini B plug I can wait to buy until later because the ability for the pandora to act like a device to another host might be implemented by software.

...right?
 
You must log in or register to reply here.

Similar threads

Matthias_H
Usb Otg Adapters - Which Ones, And Where To Get?
Replies
13
Views
3K
Nation.A.List
Nation.A.List
S
Buying A Usb Otg
Replies
2
Views
2K
sehs33
S
chris_c
Media Keys And Alarm Buzzer Idea
Replies
13
Views
3K
chris_c
chris_c
K
USB 3 OTG Port
Replies
3
Views
1K
gpsqueeek
gpsqueeek
dgame
US $6.99 Micro Wifi Dongle for Pandora
2
Replies
28
Views
6K
neomk
neomk
Back
Top