Received: by 10.50.197.137 with SMTP id iu9mr5587886igc.1.1340248468932;
        Wed, 20 Jun 2012 20:14:28 -0700 (PDT)
X-BeenThere: hackerspace_brisbane@googlegroups.com
Received: by 10.231.62.136 with SMTP id x8ls27722ibh.7.gmail; Wed, 20 Jun 2012
 20:14:28 -0700 (PDT)
Received: by 10.50.173.34 with SMTP id bh2mr1400423igc.0.1340248468293;
        Wed, 20 Jun 2012 20:14:28 -0700 (PDT)
Received: by 10.50.173.34 with SMTP id bh2mr1400422igc.0.1340248468279;
        Wed, 20 Jun 2012 20:14:28 -0700 (PDT)
Return-Path: <a.niel...@shikadi.net>
Received: from vitalin.sorra.shikadi.net (vitalin.sorra.shikadi.net. [173.255.220.46])
        by gmr-mx.google.com with ESMTPS id s10si6112197igs.0.2012.06.20.20.14.27
        (version=TLSv1/SSLv3 cipher=OTHER);
        Wed, 20 Jun 2012 20:14:27 -0700 (PDT)
Received-SPF: pass (google.com: best guess record for domain of a.niel...@shikadi.net designates 173.255.220.46 as permitted sender) client-ip=173.255.220.46;
Authentication-Results: gmr-mx.google.com; spf=pass (google.com: best guess record for domain of a.niel...@shikadi.net designates 173.255.220.46 as permitted sender) smtp.mail=a.niel...@shikadi.net; dkim=pass (test mode) header...@shikadi.net
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=shikadi.net; s=default;
	h=Content-Transfer-Encoding:Content-Type:In-Reply-To:References:Subject:To:MIME-Version:From:Date:Message-ID; bh=7Al1DcJ1JQ4G2nz0j10admXzmV0lQYkdFnCOFnd11w8=;
	b=erKGlazH442dDA/cRbWfLilbpz6/ZNLFRAW0/Duix85Aqm7oXHKVIpXb8K7EwUsqgfzOh5p5kRdRpGh/EOLITbzrFzanZVAJMT/pxyxHoASOlRaqiyzTt/wFqHPsV8m4;
Received: from arachnut.vlook.shikadi.net ([172.16.255.13])
	by vitalin.sorra.shikadi.net with esmtp (Exim 4.72)
	(envelope-from <a.niel...@shikadi.net>)
	id 1ShXqk-00045I-FT
	for hackerspace_brisbane@googlegroups.com; Thu, 21 Jun 2012 13:14:26 +1000
Received: from localhost ([127.0.0.1] helo=[IPv6:::1])
	by arachnut.teln.shikadi.net with esmtp (Exim 4.72)
	(envelope-from <a.niel...@shikadi.net>)
	id 1ShXqj-0003a3-MJ
	for hackerspace_brisbane@googlegroups.com; Thu, 21 Jun 2012 13:14:25 +1000
Message-ID: <4FE29191.7080...@shikadi.net>
Date: Thu, 21 Jun 2012 13:14:25 +1000
From: Adam Nielsen <a.niel...@shikadi.net>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1
MIME-Version: 1.0
To: hackerspace_brisbane@googlegroups.com
Subject: Re: Got my Raspberry Pi!!
References: <0A8492B6-7156-47EC-BFA3-5D45F38E2...@gmail.com> <CACvbGVN8zMy5on7gHA5o16we6XVxvuBRBmAt_f9n1JhfJup...@mail.gmail.com> <CACiBCBabj+m0hJ2TpdLHNJGhpeo4Y=aWrR0TM7w2_EZb7q+...@mail.gmail.com> <CAAxzKbSSjaKr9PhkkUFbMYkTFcSNVNrS1FioAvgSoTYZkn-...@mail.gmail.com> <AC37020B-0B9C-44E1-8AF8-91A1E794E...@gmail.com> <4FD88946.7050...@shikadi.net> <CANnr-cvDQjSVtGqzRYBg9d=UH30Yf53F_QXJRXSchJ6S6ib...@mail.gmail.com> <4FDC6835.9010...@shikadi.net> <CANnr-ctUs_2zkbc2atOyKViPo2OHUfKYiR2jieMq1cnJpw7...@mail.gmail.com> <4FDD68DF.4070...@shikadi.net> <CANnr-cu1w9SzXTeTuH6tk63mTvW3kBO3gs_k8=h1Q7iHwhF...@mail.gmail.com> <4FDE65BD.7070...@shikadi.net> <CANnr-ct+_pGnpYKh8AX=WZuz_g4if5_e968n5zsivmfaeNX...@mail.gmail.com> <4FE01364.8020...@shikadi.net> <CANnr-ct+tH3nJobhGXbFKZn2rX2SpOpW6N4G-VM989KesBD...@mail.gmail.com> <CANnr-cuJeuoubG6Z9nm5=WDok8WjFJzfF7fwLG8yGn6pGCf...@mail.gmail.com> <4FE25F12.2070...@shikadi.net> <CANnr-ct+_KxBmiqrL92qLfFwveauf9e02rgogBNJ_-CCyJy...@mail.gmail.com>
In-Reply-To: <CANnr-ct+_KxBmiqrL92qLfFwveauf9e02rgogBNJ_-CCyJy...@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

> My mistake, I actually was running Raspbian off one of my earlier class
> 4 cards. I haven't actually tried the new ones yet.

So far this new card seems to work (Pi booted very quickly, no mmc0 
errors in dmesg) but I haven't tried writing to it yet from within the 
Pi (which is what caused problems with the last one.)

> The woolies cards were 4GB each. It was faster though, I was writing the
> image at ~7MB/s instead of ~4MB/s. I haven't tried booting it though so
> I don't know if there's a noticeable difference or even if they work in
> the Pi.

There was a noticeable difference for me in boot times, but part of the 
slowdown was mmc0 errors in some of the incompatible cards slowing 
things down.

> Where are you getting these cheap cards, that may or may not be fake? :)

Just off eBay.  This latest one was a "Master" brand from seller 
"storage_specialist" (chosen in part because it looked a bit dodgy) but 
so far it's been fine.  My cheap USB card reader crashed when I ran my 
testing program on it though (getting to ~2.5GB each time then 
completely disconnecting from the USB bus and the power light going 
off), but the card reader built into my monitor worked without a hitch.

> Further to this, I measured the voltage on the Pi between the USB shield
> and the high side of the smoothing capacitor (as it's easier to get to
> without shorting GPIO pins). I pulled out the SD card so it wouldn't
> boot and it was 5.02V. Then I booted up and it was 4.70V. I tried with a
> iPhone charger and it was slightly worse. So again there might be some
> resistance due to the cable as you've mentioned, but also maybe the
> onboard regulator is dropping some voltage? I stopped shy of driving the
> power directly to the GPIO pins. I can't really see how it could be a
> problem anyway with external devices with their own power.

I imagine there's some drop from the onboard power circuitry, which is 
probably why the requirement of 4.75V is so high.  I think it then gets 
passed to the USB ports though, so if the power is too low there it 
could cause problems with devices getting their power from the onboard 
USB ports (which includes the onboard Ethernet module, which is USB2.0)

But were you plugging your wi-fi device into the USB hub?  That might 
actually explain the problem.  Have you tried plugging it straight into 
the Pi instead?  I know with desktop PCs hubs can introduce all sorts of 
problems due to the way they encapsulate the data of the downstream 
devices - but as you say, it shouldn't be related to power at least.

Cheers,
Adam.