Tuesday, 21 May 2013

THE BIT BANG THEORY : Lab tip for power connectors

This is a nice one. Its a very simple idea, that tackles the age old problem of having the right connector on the right power supply for the device you want to use.
Sure there are numerous commercial packs of adapters for phones and the like but they tend to be expensive and don't necessarily work with each other.
To get round this the author of this blog has designed his own standard, based on the cheap and easy to use Phono (RCA) plug and sockets.
It works by you chopping up your existing supply cables and attaching phono plugs to both ends. You can then reconnect them in various configurations using female to female adaptors.
The full story can be found over on the Bit Bang Theory site at http://thebitbangtheory.blogspot.pt/2013/03/lab-tip-for-power-connectors.html

Word of caution

As much as I like this idea, if I were to adopt it then I think I would limit myself to 5V supplies only, it would be too easy to mix them up other wiese and damage something.

Monday, 20 May 2013

ATX Raspi

I knew the Raspberry Pi was going to be a winner as soon as I saw the original specification, but I had no idea it would be this popular or that it would stimulate such a healthy crop of third party add-ons.
The latest one I found was this really clever little power supply controller that allows the Pi to shut itself down and disconnect its own power supply.
The power supply is reconnected to the ATX board, which is in turn connected to the Pi through GPIO pins.
What makes this so special is that the ATX has a PIC processor, which monitors the Pi while it is shutting down and only turns the power off, via its on board relay, when the Pi is completely ready.
Full details can be found at http://lowpowerlab.com/atxraspi/#whatisit
[Via Hackaday]

The Register : US boffin builds 32-way Raspberry Pi cluster

Beowulf (see http://www.beowulf.org/ ) is way to produce a high power parallel computing system by networking together a number of low cost computers with a free to use operating system, based on Unix.
This was an extremely attractive idea to university departments who wanted a huge amount of computing power on a limited budget. There are many stories of clusters being made from systems rescued from skips, and legend has it that in one London university students would swarm over the building late at night, rebooting every available PC from a floppy disk into the cluster, and then rebooting them back before anybody else arrived next morning. It would be nice to suggest that this was for Astrophysics or sub-atomic particle research, but in fact it was to run a Dungeons and Dragons programme.

An article in The Register tells how Boise University PhD candidate Joshua Kiepert  built a 32-way Beowulf cluster from Raspberry Pis.
The RPis were stacked in groups of eight with enough room between them for a reasonable amount of air flow and component clearance he writes. “This configuration suited our needs for power distribution very well since it allowed for a power line to be passed vertically along each stack."
Joshua is extremely happy with the results of his cluster and has written his work up as a PDF file, and if you have any interest in doing something similar then I can recommend reading it in detail.  The cost of this? around £1500, or the cost of a decent high powered 4 core system.
[Full story from The Register]