question: USB OTG

[Kosmos]

I came across a mini-usb-to-OTG cable and have two questions.


what can I use it for (hooking up a keyboard maybe?)


And how!


Just plugging it in and activating USBhost did nothing. (A usb keyboard I have atleast was not responsive....

 

[Binky]

I came across a mini-usb-to-OTG cable

Can you describe what connectors it has on each end?


mini-A?


mini-B?


Using the USB otg (which is mini-AB btw) should require mini-A male to full-A female for keyboards and such


And mini-B male to full-A female for connecting to a computer


If you want to connect a keyboard, you may be better off with a USB 2.0 hub

 

[Kosmos]

Its a mini-B (male) to A (Female).


I would like to know what neat things I can do with it and how (if there is anything special).


Both the keyboard and USB-flashdrive may have not worked due to insufficient power? what can it be used for then?


thanks.

 

[Binky]

Its a mini-B (male) to A (Female).

Afaik, such a thing should not exist, as both connectors would normally be wired to a host device (and would plug into a slave). Cable manufacturers are crazy!


There is a pin (held high or low) that tells the pandora (and other usb-otg devices) whether the connector you plugged in is mini-A or mini-B, the state of this pin puts the mini-AB socket in either host or slave mode, as appropriate. With a little software hacking, I believe it is possible to force it into host mode, even with a mini-B. Other than hunt around the wiki and these forums, I can't help you with what sort of hacking is actually required here


As I'm more of a mechanical and hardware engineer, I would suggest dismantling the plug and rewiring the relevant pin. Unfortunately, this will probably be utterly impractical.

 

[Linux-SWAT]

I also have this kind of cable, and it's not compatible with the Pandora.


You have to use a Nokia pin out:


http://pandorawiki.o..._Go.29_Adapters

 

[Binky]

You have to use a Nokia pin out:

Please explain/describe...

 

[Linux-SWAT]

The connections are different.


Both ends are the same, but wires are reversed. Probably the data pins.

 

[Binky]

How would I go about checking weather the adaptor I have should work or not?


It is an unbranded block of plastic with female A on one end and male mini-A on the other (will find link/pic in a mo). I haven't tried to use it much, but when I have, It doesn't seem to have worked...

 

[Linux-SWAT]

Well, we have to use an ohm meter to check routes and compare.


Can be tough as the mini pins are small.


I can do it, but not today, now i'm literally falling asleep.

 

[Binky]

My multimeter says:


fullUSB 1 --> miniUSB 1


fullUSB 2 --> miniUSB 2


fullUSB 3 --> miniUSB 3


fullUSB 4 --> miniUSB 4 and miniUSB 5

 

[ryan27968]

that means that the mini a/b sensor pin is low

 

[Loonie]

Host mode is active when pin 4 of the mini USB connector is shorted to ground (pin 5). If pin 4 is open, the device acts as a peripheral.

 

[Binky]

OK, so my adaptor is miniUSB-A both mechanically and electrically, but are the data pins reversed as Linux-SWAT mentioned? Should they be?

 

[notaz]

I think it should work, but because of driver quirks you have to load a gadget driver first, so:

sudo modprobe g_cdc

, connect the device to adapter and try plugging it to pandora.

 

[Silent-Hunter]

I think it should work, but because of driver quirks you have to load a gadget driver first, so:

sudo modprobe g_cdc

, connect the device to adapter and try plugging it to pandora.

Didn't work for me.