Powered USB hubs

[techforay]

I am have some trouble with my keyboard. It often randomly repeating characters. I did some investigating and it may be a power issue. I would like to know which powered usb hub works well for the RPI and where to buy stuff for the pi

[Mobius]

Check here: http://elinux.org/RPi_VerifiedPeripherals

Yes, power is the biggest Pi issue. If you can get your hands on a voltmeter, try checking the voltage from TP1 to TP2. If that is below 4.8 volts it is marginal at best.

[techforay]

Check here: http://elinux.org/RPi_VerifiedPeripherals

Yes, power is the biggest Pi issue. If you can get your hands on a voltmeter, try checking the voltage from TP1 to TP2. If that is below 4.8 volts it is marginal at best.

I am a little confused on this. I have tried several power sources. One of them is a 5v 1.8 a. I checked TP1 and TP2 during login and the voltage never dropped below 4.9. I still had a hard time logging in because I typed "pi" and what happened was "liiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii". I dont know if it is the voltage.

[metaljay]

What power rating is the keyboard? Is it directly plugged into the Pi? No extension cable etc?

[efflandt]

Dropped or sticky keys can depend upon the type of keyboard. What kind of keyboard do you have, and is it directly connected to the Pi or through a powered USB hub?

The Pi has had some issues with mixed USB 1.1 and USB 2.0 devices. Adding dwc_otg.speed=1 to /boot/config.txt can help avoid dropped or sticky keys by forcing USB 1.1. Although, that can slow networking and other USB devices, and make USB 2.0 "only" devices not work.

[techforay]

The keyboard works fine on other things i use it on. It has a 5V 1.5 A rating and it is plugged directly into the RPi. I am not sure what USB type it is. It is a Dell SK-8135 keyboard. I will look it up and reply back. Thanks for your help

[furrysalamander]

you need to plug the keyboard into a powered usb hub, not just the pi!

[furrysalamander]

also, I own a cyberpower 4-port usb hub that I use with my pi, the power supply provides 2.6 amps at 5 volts; plenty to run both your pi and your keyboard. How I have mine setup is the pi gets its power from the hub, the hub is plugged into the pi, and my high power devices are plugged into the hub, like your keyboard. They also make 7-port hubs. If this helps anyone, I would hope that you would take a look at my question on dual booting pwnpi and raspbian.