Pandora Otg Usb Plug

[kingoddball]

Hi There,
I'm just after a quick answer about the OP OTG plug.
I have seen somewhere that its not a standard plug (Like the ones found in millions of other devices [ps3 remote, phones, cameras].
Is this true?
I would like to use something dumb and simple like a gender changing plug (to use fullsize USB) I also have other ideas, like soldering directly to the OTG lines internally and maybe try and install a 3G modem internally.. I don't care about what can be done inside or too much.

I cant remember which forum post I have seen that said it was different, it was recently.

Thank You! andora2ut4: h34r:

 

[shunun]

A 3g modem hey? Thats an interesting idea. Sorry i cant answer your question. I thought the OTG was just a mini usb port like any other.

 

[WizardStan]

An OTG port is basically a normal slave port (ie, the plug that would allow you to connect it to your computer, just like on an MP3 player or camera) but with the right adapter becomes a host port that allows you to plug something into it instead. I'd like to know the quote that said it was "different".
I believe there is no more room inside the case for anything, so soldering in a 3G modem probably won't pay off, though I can't imagine any other reason it wouldn't be posible.

 

[shunun]

I think it's much easier to just use an external 3g modem, surely thats not to difficult?

 

[gruso]

It's a Mini A-B port, which makes it slightly different to the usual mini USB port you see on every device (that's just a Mini A, I think?). As Stan says though, you still use it the same way as a regular "slave" mini USB port, and it fits the same USB-to-mini-USB cables that you already own.

If you want to use it in "host" mode, a size adapter / gender changer will be of no use. You need a purpose built OTG adapter, which not only converts it to a standard size female USB, but ties one pin down to ground so the chip knows to switch into host mode.

My favourite link: http://pandorawiki.org/USB

 

[gruso]

That's it.

 

[BackAssward]

Do we know if it will natively act as usb storage and automatically show up when plugged in (e.g. hardware implemented), or if the OS on the Pandora will have to be setup to do this function.

 

[kingoddball]

Thanks for the replies.
Another question then: Can I get an adapter and just plug in a 3G key (I actually found one last week) and it will work (forgetting drivers/software etc)?

 

[Dead1nside]

I don't suppose somebody's made a list of suppliers of these USB OTG adaptors have they? I'm looking for one available in the UK. Thanks.

 

[kingoddball]

I'm not sure we need anything fancy after reading the link Gruso supplied..
Thank you Gruso!
As for suppliers, eBay has many, many, MANY adapters! Piss Cheap too!

Power consumption will be the biggest issue! 100mA compared to the 500mA from normal.


What does “OTG” mean?

OTG stands for On The Go. USB OTG ports can operate in two different modes. When connected through this port, the Pandora can act as a device, for example when connected to a computer for charging & data transfer. For this mode, you need a standard-A to mini-B cable. However, the Pandora can also act as a host port for USB 1.1 and USB 2.0 devices. For details on how to make the necessary cable connection, see the OTG host mode section. This port can supply a maximum of 100mA in host mode. Although this port implements On The Go functionality, it can not get an official On The Go certification because the OTG specification requires a device to have exactly one USB port. (The Pandora has two.) Also, the mini-AB connector used on the Pandora has been taken out of the specification in 2007 (but is still widely adopted).

OTG host mode
Pandora in OTG host mode
Pandora in OTG host mode

How you connect a device to the mini-AB OTG port depends on the device's USB connector.

* standard-B receptacle: Use a mini-A to standard-B cable.
* mini-B receptacle: Use a mini-A to mini-B cable.
* micro-B receptacle: Use a mini-A plug to standard-A receptacle adapter and a standard-A to micro-B cable.
* standard-A plug: Use a mini-A plug to standard-A receptacle adapter.
* mini-A plug: No extra cable or adapter needed.
* micro-A plug: No standardized solution exists.

This port allows you to connect a USB 1.1 device directly, without the use of a hub. This port is also USB 2.0 compliant.

Notes:

* mini-A and mini-AB connectors have been removed from the present USB standard. This means that the above connectors may vanish from the market at some point (although there will probably be demand for them for some time). There are a lot of connectors available that were never standardized. It is recommended that you do not use them as they may lead to non-working connections. Stick to the cables and adapters mentioned above and look for a mention of "OTG" or "On The Go" and you should be on the safe side.
* In host mode, this port can supply a maximum of 100mA. USB 1.1 devices that draw more than 100mA will need to connect to Pandora's other USB port via a hub, as depicted in the previous example. The Huawei E220 is one such device.

 

[gruso]

Thanks for the replies.
Another question then: Can I get an adapter and just plug in a 3G key (I actually found one last week) and it will work (forgetting drivers/software etc)?

Yes, if:

1. It's supported in Linux (many are)

2. It doesn't draw more than 100mA - that's the limit of the OTG port.

Chances are it will need more power than that though, so you'll probably have to use the main USB port. And if you're using the main USB port, your 3G key will have to be High Speed certified (see USB page on wiki for the logo to look for).Or you'll need to run it through a hub.

[edit] Oh, I see you got yourself a fishing rod.

OTG adapters are pretty generic things, so eBay and Amazon are the easiest places to buy them. Links here: http://pandorawiki.org/USB_compatibility_list

Protip: Don't buy those $3 blue ones. They're bulky and stiff.

 

[kingoddball]

Thanks for the replies.
Another question then: Can I get an adapter and just plug in a 3G key (I actually found one last week) and it will work (forgetting drivers/software etc)?

Yes, if:

1. It's supported in Linux (many are)

2. It doesn't draw more than 100mA - that's the limit of the OTG port.

Chances are it will need more power than that though, so you'll probably have to use the main USB port. And if you're using the main USB port, your 3G key will have to be High Speed certified (see USB page on wiki for the logo to look for).Or you'll need to run it through a hub.

[edit] Oh, I see you got yourself a fishing rod.

OTG adapters are pretty generic things, so eBay and Amazon are the easiest places to buy them. Links here: http://pandorawiki.org/USB_compatibility_list

Protip: Don't buy those $3 blue ones. They're bulky and stiff.

Hahahaha.
I like the fishing rod part! B)
Another question, 100mA is very weak, but could we use a powered usb hub via the OTG port and sneak power that way?
Its not worth the effort, but I just like to know in case one day I would like to use it.
I think using it for its intended purpose is the best use, I just like to know I can do whatever is necessary for whatever evil ideas I think up :huh:

Also, I have never seen/heard of MBB Modems needing to be HS certified, wouldn't they all be cert'd anyhow? I have 2 different ones, one from 3Mobile about 8 months old - E160G, and a newer similar one I found last week which is Vodafone - K3520 - Looks similar, just more rounded design.

 

[gruso]

Most newer ones should be HS certified - I think the E160 is. The older E220 isn't. I've got an E220, so I'll be using it with one of these.

 

[palmertech]

This discussion reminds me of the days of painstakingly pulling apart several miniUSB B connectors to tie pin 4 to 5 so I could use OTG on my N800. This is before OTG adapters were common, and just weeks before the software switch was made.


Good times, good times...

And will we be able to switch into OTG mode through software in case we happen to be using a simple gender/type adapter with no pin pull down? I know the N800 and N810 could do it, I would be surprised if the pandora could not.

 

[kingoddball]

This discussion reminds me of the days of painstakingly pulling apart several miniUSB B connectors to tie pin 4 to 5 so I could use OTG on my N800. This is before OTG adapters were common, and just weeks before the software switch was made.


Good times, good times...

And will we be able to switch into OTG mode through software in case we happen to be using a simple gender/type adapter with no pin pull down? I know the N800 and N810 could do it, I would be surprised if the pandora could not.

Hi there!
This is a very good question.
It would be good to have a solid answer - here's looking at you mr Gruso!
But, as far as I've seen today, you should not need to screw around with it too much anyhow. You can just use an adapter to get simple low powered devices to run. It's very low powered.

 

[gruso]

I can't answer that one!

 

[atomicthumbs]

I kinda hope you can do stuff like switching the Pandora between mass storage mode and USB networking mode (penetration testing, etc.)

 

[Matthias_H]

Chances are it will need more power than that though, so you'll probably have to use the main USB port. And if you're using the main USB port, your 3G key will have to be High Speed certified (see USB page on wiki for the logo to look for).

This is something that keeps on confusing me quite a bit. So regular low-speed and full-speed USB 2.0 devices will not work on that port, only high-speed ones? This seems pretty unusual... According to the OMAP 3530 datasheet, the chipset should support all three flavours of USB 2.0 devices:

http://focus.ti.com/lit/ds/symlink/omap3525.pdf

• High-Speed/Full-Speed/Low-Speed USB OTG Subsystem (12-/8-Pin ULPI Interface)
• High-Speed/Full-Speed/Low-Speed Multiport USB Host Subsystem
  • 12-/8-Pin ULPI Interface or 6-/4-/3-Pin Serial Interface
  • Supports Transceiverless Link Logic

 

[yannv]

This is something that keeps on confusing me quite a bit. So regular low-speed and full-speed USB 2.0 devices will not work on that port, only high-speed ones? This seems pretty unusual... According to the OMAP 3530 datasheet, the chipset should support all three flavours of USB 2.0 devices:

It does. However, if you'll inspect the USB subsystem of a typical computer...

yann@junk:~$ lspci|grep -i USB
00:13.0 USB Controller: ATI Technologies Inc SB600 USB (OHCI0)
00:13.1 USB Controller: ATI Technologies Inc SB600 USB (OHCI1)
00:13.2 USB Controller: ATI Technologies Inc SB600 USB (OHCI2)
00:13.3 USB Controller: ATI Technologies Inc SB600 USB (OHCI3)
00:13.4 USB Controller: ATI Technologies Inc SB600 USB (OHCI4)
00:13.5 USB Controller: ATI Technologies Inc SB600 USB Controller (EHCI)
yann@junk:~$ lsusb -t
/:  Bus 06.Port 1: Dev 1, Class=root_hub, Driver=ohci_hcd/2p, 12M
/:  Bus 05.Port 1: Dev 1, Class=root_hub, Driver=ohci_hcd/2p, 12M
/:  Bus 04.Port 1: Dev 1, Class=root_hub, Driver=ohci_hcd/2p, 12M
/:  Bus 03.Port 1: Dev 1, Class=root_hub, Driver=ohci_hcd/2p, 12M
/:  Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ohci_hcd/2p, 12M
/:  Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/10p, 480M
    |__ Port 2: Dev 3, If 0, Class=hub, Driver=hub/2p, 480M
        |__ Port 1: Dev 4, If 0, Class=hub, Driver=hub/6p, 480M
            |__ Port 2: Dev 6, If 0, Class=HID, Driver=usbhid, 1.5M
            |__ Port 2: Dev 6, If 1, Class=HID, Driver=usbhid, 1.5M
            |__ Port 3: Dev 7, If 0, Class=HID, Driver=usbhid, 12M
            |__ Port 4: Dev 8, If 0, Class=HID, Driver=usbhid, 1.5M
        |__ Port 2: Dev 5, If 0, Class=HID, Driver=usbhid, 1.5M
        |__ Port 2: Dev 5, If 1, Class=HID, Driver=usbhid, 1.5M

There are two types of controllers in there, OHCI (or UHCI) and EHCI. The EHCI ones only deal with high speed (480Mbps) devices, the others with low (1.5) or full (12) speed, and both connect to the same ports (10 in this case). On the Pandora, we have one of those high-speed only ports on a separate connector, so we get an extra (albeit limited) USB host port. That's why you need a high-speed hub to translate for lower speed devices on that port. It also relates to a problem with some USB hubs, where you may get reduced performance on full speed devices because they share a single translator (better hubs have one per port).
At least, that's the reason I've been guessing all this time.. I could be wrong.