belugaboss
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Re: Will the RPi support a USB hub?

Sat Mar 24, 2012 11:49 pm

I was wondering how I could achieve wireless connectivity through the USB connector. I decided with a wireless USB adapter I could run my keyboard and mouse off of one port and then my wireless Wifi USB off of the other. But then I realized that the posts may be too close for the two devices to stack on top of each other. So my question still stands, if the RPi can handle a USB hub, how many ports can it support?

Thanks, and great project so far guys! -Nick

Smartybones
Posts: 176
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Re: Will the RPi support a USB hub?

Sun Mar 25, 2012 12:18 am

if I recall correctly, USB 2.0 can handle up to 127 ports.

as the usb standard can transfer a maximum of 480 Mbit/s data rates will drop off way before that maximum of 127 ports is reached….

careful configuration of the connection of hubs can maximize the bandwidth available to devices needing a higer data rate….

not forgetting that the raspberry power supply needs 700mA, its recommended that you use powered USB hubs…..

and to add,,,, your keyboard and mouse will need a usb port each (unless your keyboard has a usb hub built in) so if you wanted to plug wifi adaptor in, you would have to use a hub anyway.

secretreeve
Posts: 330
Joined: Mon Feb 20, 2012 8:39 am

Re: Will the RPi support a USB hub?

Sun Mar 25, 2012 1:00 am

actually most wireless usb keyboard and mice combinations have just 1 receiver for both devices, therefore only 1 usb port is required if the board and mouse is a set.

another alternative is those short usb extension leads, just to allow more room.

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RaTTuS
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Re: Will the RPi support a USB hub?

Mon Mar 26, 2012 7:15 am

yes the RPi can use a HUB- in fact a powered hub may be the best way to go forward [say with 8 ports]

power the RPI from the Powered Hub with an USB -> micro USB cable

run your other things from the hub

Job done.

[10 + 10 = 100]
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Newbie
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Re: Will the RPi support a USB hub?

Mon Mar 26, 2012 10:27 am

Be aware that if you"re going to try using a wireless mouse/keyboard using one of the typical 2.4 GHz dedicated/proprietary USB dongles, it"s going to not only need a Linux driver, it"s going to need an ARM Linux driver. I"ve had numerous problems with such keyboards/mice just between various versions of Windoze ... caveat emptor!

mole125
Posts: 228
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Re: Will the RPi support a USB hub?

Mon Mar 26, 2012 10:36 am

Newbie said:


Be aware that if you"re going to try using a wireless mouse/keyboard using one of the typical 2.4 GHz dedicated/proprietary USB dongles, it"s going to not only need a Linux driver, it"s going to need an ARM Linux driver. I"ve had numerous problems with such keyboards/mice just between various versions of Windoze ... caveat emptor!


Really? I've not used many but if it is a USB dongle then I would expect it to present itself just a bog standard HID mouse and keyboard - the computer doesn't/shouldn't need to know that it isn't actually a wire attaching the mouse/keyboard to the dongle all it cares about are the key presses.  It's possible that you may need software to do the pairing (again all the ones I've seen just use 'pair now' buttons) but it is an expensive approach to waste time developing drivers when you can just design it to use the ones built into windows.

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Jongoleur
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Re: Will the RPi support a USB hub?

Mon Mar 26, 2012 11:13 am

@Newbie;

ALL the wireless mouse/keyboard sets with USB and PS2 connectors I've encountered have presented themselves as generic Human Interface Devices (HID), in other words, the wireless receiver presents to the computer as if it were a keyboard and a mouse, with no need for a device driver.

Where you may be going adrift is that some sets offer additional functionality, allowing non-standard keys to be assigned to special purposes.  The software to support this is often Windows specific and has problems co-existing with different versions of Windows (Vista broke a lot of XP add-ons!).  Otherwise, the keyboard and mouse will function perfectly correctly.
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