Saturday, October 13, 2012

RPi keyboard performance issues

I've been having a lot of fun playing around with my Raspberry Pi for the last four months.
In general, however, I've done little other than research how close to a fully functional Desktop computer I could get with this little, and very under-resourced, machine.

Any answer to this question is likely to start with "Well, .......".
Yes, the RPi is a bit of a pain to use if you're expecting it to replace your iMac.
On the other hand, for a machine that I could slip under my pillow and not notice it while sleeping, and with just a 700 MHz CPU and 256 MB of RAM, which would have been considered under-resourced ten years ago, what is possible with this machine is truly admirable.

However, one big problem for me was the constant battle with the keyboard. For basically all of the OSes I've used, typing was a pain due to missed letters and frequent repeats.
Indeed, this problem almost made my RPi unusable.

This issue is addressed in the Wiki troubleshooting pages and puts the problem down to low power (which, indeed, is the cause of many, if not most, RPi problems.)

But, hold on..........I'm using a Nokia AC 10E (5V, 1.2A) PSU which is listed as a working power adapter in the Wiki and a powered USB hub (Belkin F4U020) to plug in my wifi dongle.
Additionally, the dongle for my wireless mouse and keyboard is plugged straight into my RPi (in response to this forum post claiming the repeats problem was due to a usb-driver to hub issue, I moved the keyboard dongle from the hub to the RPi) how could anything be wrong.

Let me think.....that wifi dongle in the hub flashes an awful lot, and, come to think of it, I really don't need wifi as my ethernet works just fine.
Also, in Debian where I haven't yet configured the wifi, typing is perfect.
Hmmm...let's take out that wifi dongle.
Sure enough, that absolutely did the trick!!!
No problems typing in overclocked Raspbian or Fedora 17 RC2 on my RPi.

Nevertheless, there's still something very strange here. The wifi dongle was plugged into a powered hub, so how could that be reducing the power available to the wireless keyboard dongle plugged directly into the RPi?
However, given this experience, this is the obvious and perhaps the only conclusion.

Anyway, I'm extremely relieved to have removed that huge problem.

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