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Showing posts from 2017

I've got the power

(It's getting, it's getting, it's getting kinda hectic)

So, another "I should really get round to that" project that's worked its way to the top of the desk is repurposing a skip-dived server PSU (or 4) to be more usable.

Exhibit A - One ex-sun 'SPASUNM-03G' PSU, which spits out a fairly chunky 12v at 86.7A
Since these were pulled from a bunch of servers, the output is a less than friendly set of three paired contacts for +12 and another set of three pairs or the ground. It won't start spitting out 12v when you plug a mains lead in as it needs the PS_ON connector bringing low. Power-one seem to gave been bought out by bel, and the datasheet is available here.

Rather than the (sometimes) crude way people have modified these and similar server PSUs over at RC Groups, I thought I'd hook up an arduino and be "smart"
So - Grand Plan (TM) * Nice big illuminated push button for on/standby * LCD display to show status (output / alarms / temp…

Handheld animal RFID reader teardown

As some of you may know, we have a small herd of llamas and although each is easily recognisable legislation and the Llama Association of Australasia Inc. require that the animals be microchipped. As a geek, I'd also like to integrate routine monitoring of weight, so my idea is to use the embedded microchips (same as your pet FDX-B 'grain of rice' thing) to save the scale output into the relevant animal record (yup, another use of a Raspberry Pi in the steading)

Aliexpress provided the reader, and 5 small screws later (and another 2 for the PCB) has the innards exposed at https://www.flickr.com/photos/elwell/albums/72157683149501201