[clug] ATX r pi

[Rodney]

I like (and use) that general approach.

I have a pi B running as a firewall/router and power it via an old 2.5 A 
powered USB 1.1 hub.  12 Mb/s is adequate for my modem & WAP via USB/Ethernet 
adapters.  I do have a modern USB 2.0 powered hub having a 2 A plugpack, but 
reserve that for my low wattage desktop, which has only 4 USB ports.

Hardware specs for the pi are hard to come by.  Archlinux suggest that the 
model B can draw 1200 mA at full tach & pi are known to crash/lock on 
inadequate power.  Archlinux also suggest that early Pi could deliver only 140 
mA in aggregate to the USB ports.  lsusb is an essential command for pi users.

BTW, the pi (and I gather many ARM based devices) effectively use the USB bus 
as their I/O bus.  The pi uses a SMSC LAN9512 chip that is designed 
specifically for that style of use.  It is primarily a USB controller but also 
provides 10/100 Ethernet from it as well as driving LED etc.  Gigabit 
Ethernet/USB adapters are an oxymoron at the best of times and particularly so 
with a pi.

BTW2, pi have recently changed to Hynix memory chips and that requires a 
different compilation, which some distros are not doing.

http://planet.ipfire.org/search?q=arm


Rod 

 On Sun, 17 Nov 2013 12:00:06 linux-request at lists.samba.org wrote:
> Message: 1
> Date: Sun, 17 Nov 2013 06:23:02 +1100
> From: Brians <brians at en.com.au>
> To: linux at lists.samba.org
> Subject: Re: [clug] ATX r pi
> Message-ID: <5287C616.8030907 at en.com.au>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> The rpi has only two USB ports which are often used by a keyboard and
> mouse and then you need a few more ports ie memory stick, external 2
> 1/2"  harddisk etc
> 
> A powered USB hub is often used to provide more USB ports and also if
> the hub has a 2 amp or more external power supply provide the 5VDC to
> power the rpi itself.
> 
> A model B rpi only uses around 800mA or around 4 watts.
> 
> Bunnings have a 2000 mA 5VDC seven usb port powered hub for around $30
> which works well with a rpi.
> 
> Jaycar and many other places sell powered usb hubs, just make sure that
> it has a minimum 2 amp supply.
> 
> Alternatively use a spare USB phone charger or a cigarette lighter usb
> car charger.
> 
> On 17/11/13 05:42, John Mills wrote:
> > On Sat, Nov 16, 2013 at 12:46:47PM +0000, Logan McLintock wrote:
> >> Date: Sat, 16 Nov 2013 12:46:47 +0000
> >> From: Logan McLintock <u4955237 at anu.edu.au>
> >> Subject: [clug] ATX r pi
> >> To: "linux at lists.samba.org" <linux at lists.samba.org>
> >> 
> >> Hello my friends,
> >> 
> >> I and working on a holiday project (my exams went well) and I want run a
> >> raspberry pi off an ATX power supply?>
> > 
> >
> > You might want to be aware, especially for testing and for a low-current 
> > application, that some PC power supplies will only run with a certain 
> > minimum load.
> >
> > 
> >
> > http://www.tomshardware.com/reviews/power-supply-specifications-atx-refere
> > nce,3061-13.html>
> > 
> >
> > (Hmm, this text is very similar to my Mueller 5th edition...)
> >
> > 
> >
> > John Mills
> >
> >