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#1 Teaker1s

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Posted 21 August 2012 - 05:01 PM

Hi I wonder if anyone can answer a question I don't seem to be able to find the answer.
Certain android devices have OTG usb that supports keyboard,mouse and flash. There are OTG Hubs and non OTG hubs for usb.

1) If you have OTG USB port do you need a normal hub or OTG Hub if you wish to extend this feature? I'm guessing a normal hub as a slave?
2) OTG USB supports flash memory-does this automatically mean the hub will boot from flash-or does it still rely on boot loader programed to look for usb devices at boot?

Sorry if these questions seem unusual, but I have looked for days without success
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#2 Leofree

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Posted 02 October 2012 - 04:49 PM

OTG have different profiles like USB storage USB Cam etc... Some manufactures supports different profiles USB hub address multiplexer I think you can use standard USB hub with power option
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#3 pkwaf

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Posted 22 November 2012 - 11:25 AM

I have just bought a usb OTG for my Onda tablet, but it does not work!
What are the different OTG and how to know which one to buy if I want to use it to connect a USB pendrive to the tablet?
I am a novice in those technical matters.
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#4 L.MCH

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Posted 26 November 2012 - 11:21 AM

I have just bought a usb OTG for my Onda tablet, but it does not work!
What are the different OTG and how to know which one to buy if I want to use it to connect a USB pendrive to the tablet?
I am a novice in those technical matters.


What do you mean for "you bought an USB OTG" ?
An USB converter cable (micro USB to "normal" USB) or something else ?

An USB OTG port is just an USB port that can work either as an USB host port or as an USB device port depending on the USB port on the other side of the connection.

An USB device port is "passive", it waits to be powered up by a connection to an USB host port and then answers to
requests and commands coming from the USB host and supported by its device configuration (i.e. a mass-storage device will answer to mass-storage specific commands, but not to keyboard specific commands, etc.).

An USB host port on the other hand can provide power to an USB device port directly connected to it (for devices that require external power
or that can recharge while connected) and usually controls the communication and configuration of USB devices connected to it ... but only if "behind" the USB host port there is an O.S. with drivers/modules that can handle the USB devices connected to it.

An USB OTG port by default operates as an USB host port, but if it is connected to an USB host port (or another USB OTG) as soon as it detects the other side of the connection is providing power or sending host commands, it switches to USB device mode.

I.e. An USB pendrive device becomes visible to the tablet only if connected to the tablet USB host/OTG port and the O.S. has at least a driver/module that can handle generic mass-storage USB devices and the pendrive is formatted with a supported filesystem (usually FAT32 works both on Androdi and Windows, while ExFAT or NTFS may cause troubles the Android build in your tablet's firmware has not been compiled with support for them).

I.e. An USB OTG port on a tablet/smarphone, when not connected defaults to host mode (so if you connect an USB mouse/keuboard/pendrive and it has drivers for them, they can be recognized and used by the tablet) but if you connect it to the USB host port of a notebook or desktop computer, it detects the host on the other side and switches to device mode, presenting itself as a mass-storage device (plus as an ethernet-over-USB or serial-over-USB device if debug mode is active to let out connect to it with ADB).
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#5 pkwaf

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Posted 29 November 2012 - 04:46 AM

Well, it would appear that it was not an USB OTG that I have got, but just a simple usb device.
A question though: will a "microUSB (male) to normal usb (female)" convertor for Samsung smartphones be compatible with ONDA V971 tablet? I ask because a friend of mine told me that the shop attendant informed him that these convertors work only for Samsung phones.
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#6 rev667

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Posted 10 January 2013 - 04:58 PM

I have a Novo7 Mars, it didn't come with an OTG cable.... so I made one.

How To Make an OTG cable

It was a bit fiddly but it works... The trick is the link between pins 4 and 5.

Hope this helps.

Rev
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