Freesteel Blog » Weekends

Thursday, April 16th, 2015 at 12:54 pm - - Weekends

A once in a lifetime experience required me to celebrate with a full-on McDonald’s burger.
bigmac
It was horrible.

Time to go home.

Sunday, April 5th, 2015 at 7:26 pm - - Kayak Dive, Whipping

I’ve washed up on the annual Easter university diving trip, though my heart’s not in it. There’s a long period of stable weather forecasted, which should mean the silt will have time to settle out of the water ready for when the novices to get good enough to come out to more exciting locations.

sennendive
snakelocks anemone encrusted wreckage in Sennen Cove

It’s a bit of a rehash: I’ve done them all before in previous years in better conditions, with Becka by kayak back in 2010. I’m too tired at the end of the day to do any of the hacking I’d hoped for, so I’m marking time. Maybe I should go to the pub more often and not try to make best use of my time all the time.

Curiously, that last time in Cornwall (but one) also coincided with a General Election campaign, and I remember a big Conservative Party poster in a farmer’s field at the end of the lane. There isn’t one there this year. Either the land-owner is not so keen on Cameron this time, or he can’t be bothered, or he’s sold up to a new owner, or who knows? It’s another metric that could have been noted and cross-correlated over the years if we really had the data. For the life of me, I don’t know why these posters never became a substrate for some time-limited concentrated geocaching game. Geocaching happens on a lot sillier things, and this could have been like tracking down sightings of rare wild animals.

fishinweeds
Fish approach between the boulders and kelp

Meanwhile, the serious programmers are making hay with the ElectionLeaflets.org site and Parliamentary candidates CVs.

Watching them discuss stuff I realize I’m totally lost in the last century in terms of the technology. It’s a full time job just keeping up. (And in the large software company I briefly worked for, nobody seemed to be employed to keep up, so they didn’t.) Nowadays I don’t know much more than the difference between JPEGs and PNGs.

Other projects are pinging up around the net, such as VoteForPolicies.org where they blogged their technical case study like so:

We are using the RabbitMQ messaging system, our queue server is run by CloudAMPQ (Big Bunny instance, dedicated server)…

Our worker servers also live behind an ELB but don’t have auto-scaling enabled; we manually manage the amount of instances based on the size of our queues, we can check using the RabbitMQ management console…

All of our MySQL queries are handled by the Doctrine ORM and written using the Doctrine QueryBuilder. These doctrine queries are also cached in Redis as SQL…

Our application is based on Symfony 2.6.* standard edition.

For Redis we use the SncRedisBundle. For RabbitMQ interactions we are using the RabbitMqBundle.

We’re using the DoctrineMigrationsBundle for database migrations and the data-fixtures and AliceBundle for database fixtures.

Our CI tool Jenkins runs all of our tests and triggers a new capistrano deployment if they pass.

Is it me, or does it feel like I’m in the world of The Hitchhiker’s Guide to the Galaxy reading about how to build a Globular Cluster Information Hyperdrive?

And this, all in the name of electing Members of Parliament, an institution whose daily procedures were already antiquated back in the Victorian era.

Once the process of governance starts getting anywhere near state of the art web technology, it’s going to be awesome.

Or it will be a whole lot worse. You never know.

As the human debacle around the science of climate change has proved, this tech is equally good at spreading knowledge and intelligence or ignorance and stupidity. It’s our choice as to what we want from it.

Tuesday, March 17th, 2015 at 8:39 am - - Hang-glide

Here I am at a climbing wall in Bristol, having balked at the price and instead sat in the cafe. They ought to have a discount rate for people don’t actually like climbing. Here’s what I enjoy instead. (I am so predictable):

pontwales

Brrr, it was cold in grimmest South Wales on a grim Saturday when all the colours are grey and the light makes everything flat. I enjoyed a sublime hour long flight above Pontlottyn, even though I didn’t go anywhere except soar up and down the ridge alone and then top land in a howling gale.

My box of tricks is in the 3D printed purple box on my left next to the airspeed indicator. I’ve not had the chance to do anything with the data except plot it and go: “that’s pretty noisy” at the accelerometer data. I have plans to extract consistent correlations, barometer vs altitude vs temperature, bar position vs wind speed, roll angle vs turning rate registered on the compass, and whether I keep diving out of turns because I don’t have enough speed and control.

Unlike my so far doomed attempts at manipulating house and fridge temperature data, this flight dynamical system is memory-free. The same temperature, pressure, windspeed, and wing angle at any time of the flight should result in exactly the same response. Deformations of the wing are brief and temporary. This is not the case for the fridge where every cycle begins with a different temperature distribution within the dense cabbagy foodstuffs and chemical pumping machinery.

Subject to instrumental noise and turbulence, all the data should be with me, and I can only hope this isn’t going to end up as just another one of my expensive failed software projects that looked plausible when I began, but then crash landed in the trees.

Wednesday, March 11th, 2015 at 3:35 pm - - Hang-glide

In spite of being up to lots of things, I’ve not been very interested in blogging of late.

I got my first flight of the year — a 3 minute top-to-bottom that began with a nil-wind terror swoop on take-off, followed by my almost forgetting to unzip the harness on landing due to being distracted by the sight of ducks paddling around in one corner of the water-logged field.

landingshadow

Here’s the data stream from the landing.
landingdata
Vertical lines at 5 second intervals. Yellow for barometer (air pressure rises as I descend), red for airspeed, cyan for GPS ground speed (seeming to correspond), white accelerometer pitch measurement, showing the pathetic flare coming into landing when all the speed drops off. The previous hump may correspond to the final approach turn (you have to push out to tighten the turn to a turning circle of about 35metres).

takeoffdata
Here’s the take-off sequence, with a slight push-out which was not held long enough, so I dropped very fast. The yellow for the barometer briefly goes below the starting value showing that at one time I got a bit of lift and could have been almost half a metre above take-off.

All in all, quite disappointing, but I’m glad to have some data to work with from my electronics device. I’m going to really appreciate the next flight when I stay up for a bit.

hgelectronics
Oh yeah, here’s a close-up of the one corner of my dog’s breakfast electronics project.

boxprinting
Luckily, 3D printers can print anything — including the abominable box I’ve “designed” in OpenSCAD to cram that electronics stuff into.

machtooldoes
Meanwhile, all this will probably be shelved due to this widget showing up in the hack-space this lunchtime. More later.

Sunday, January 11th, 2015 at 9:10 pm - - Hang-glide 1 Comment »

By not including a datasheet with their airspeed probe, Brauninger/Flytek gave me the pleasure of two successful days of hacking involving an oscilloscope and much experimentation to work out its parameters and build a circuit to exploit them.

I bought this thing as an optional add-on to the Flytec 6030 (which I’ve never got to grips with) back when I had more money than sense. I wouldn’t have got it for the purpose of reverse engineering like this because I couldn’t do electronics then, and anyway I’d have rated the chances of success as quite low.

Nevertheless, by applying various voltages and different directions and blowing on the propeller to get a response, I established that if you apply a positive current on the tip of about 1Volt (and ground the other connection), the device exhibits a resistance of between 11200 Ohms and 12000 Ohms, depending on the position of the blade.

This was a job for a Wheatstone bridge:
wheatstonebr

You can actually see the voltage differences (in millivolts) over 1/12 of a turn of the propeller:
proplowvolt
prophighvolt
(more…)

Tuesday, December 30th, 2014 at 2:27 pm - - Cave

This trip round the Lleyn followed on from last year’s Avoiding Nadilog by Walking in Wales. In retrospect nothing much happened. But it was exciting at the time due to the lack of planning and the risk of things going wrong.

whistlesands
Our white Xmas on Whistling Sands

Departure was delayed till the morning of the 24th because someone couldn’t possibly miss their 14th digging trip of the year in ODB. Anyway it was raining and we weren’t packed yet.

(more…)

Sunday, December 7th, 2014 at 4:14 pm - - Cave, Kayak Dive, Machining

I’m going to do some other coding, now that I got this result. The code would fall apart if I touched it again.
impslicesubdiv

Next on the list of things to do is clear out the vast quantity of rubbish left in the code, completely redo the subdivision loops and make the logic robust, apply it to multiple z-levels and plot slices, then make it test against edges and faces (not just points), and package it into a self-contained (but very slow) version of the slicer.

I don’t know how long this will take, as there are many other distractions available.
(more…)

Thursday, November 6th, 2014 at 1:08 am - - Hang-glide

Just when I thought it was over for the summer, there came a chance to go flying at Llangollen. It seems there are more hang-gliding conditions this year than kite-surfing conditions, which is not what I’d hoped.
(more…)

Wednesday, October 22nd, 2014 at 3:02 pm - - Weekends

How does anyone hold down a proper job?

OLYMPUS DIGITAL CAMERA
I just got a “Hello world” program working out of a pair of Jeenodes kicking around in the cardboard box left over from the Housahedron project before they migrated to Berlin. Of course, there was no documentation for how to plug in the interface into the Jeenode, and I had to get Adrian’s help.

(more…)

Friday, October 3rd, 2014 at 11:55 am - - Kayak Dive

Aside from having to get up at five in the morning and Becka not skiving the day to come along on the boat, it was a perfect trip out.

OLYMPUS DIGITAL CAMERA

Liverpool is starting to look a lot like the Esbjerg did the first time I caught the ferry over to Denmark in 2003 and saw spinning wind turbines everywhere.

OLYMPUS DIGITAL CAMERA
What amazing kit — the original gopro camera still hasn’t broken. I record these videos for the same reason I write phone numbers down in a book or keep a trip log: I can’t remember things well enough.

The water was pretty warm at 16degrees. I wore all my layers under the drysuit anyway and barely felt a thing swimming around. It was like a dream. I didn’t take any lobsters, but the others did. The conger eels stayed in the cracks while the tompot blennies came out to play.

stars
The second dive was on the Calcium where there was one large cod and more starfish than grains of sand.

There was a surprise party in the evening, which I thought was for my birthday, but wasn’t.