Planet Linux Australia

Syndicate content
Planet Linux Australia -
Updated: 42 min 8 sec ago

Leon Brooks: Making good Canon LP-E6 battery-pack contacts

Tue, 2015-08-18 15:29
battery-pack contacts

Canon LP-E6 battery packs (such as those using in my 70D camera) have two fine connector wires used for charging them.  These seem to be a weak point, as (if left to themselves) they eventually fail to connect well, which means that they do not charge adequately, or (in the field) do not run the equipment at all.

One experimenter discovered that scrubbing them with the edge of a stiff business card helped to make

with (nonCanon this time) charger contacts

them good.  So I considered something more extensive.

Parts: squeeze-bottle of cleaner (I use a citrus-based cleaner from PlanetArk, which seems to be able to clean almost anything off without being excessively invasive); spray-can

equipment requiredof WD-40; cheap tooth-brush, paper towels (or tissues, or bum-fodder).

Method: lightly

brush headspray cleaner onto contacts. Gently but vigorously rub along the contacts with toothbrush. Paper-dry the contacts.

Lightly spray WD-40 onto contacts. Gently but vigorously rub along the contacts with toothbrush. Paper-dry the contacts.

wider view of brush on contacts

(optional) When thoroughly dry, add a touch of light machine oil. This wards off moisture.

This appears to be just as effective with 3rd-party battery packs.

James Purser: Rethreading the Beanie

Tue, 2015-08-18 00:30

So there hasn't been any activity over at (actual podcast wise) since October last year.

I keep meaning to reboot things but I never quite get around to it and I've been thinking about why.

I think it boils down to two problems:

Firstly, I suffer from "Been there done that itis", that is once I've done something I tend to start looking around for the next challenge.

Secondly I suffer from a severe case of "creators block".

For instance, I have twelve different episode ideas for Purser Explores The World, a series I really enjoy making because it means I get to learn new things and talk to interesting people. I mean I've covered everything from Richard the Thirds remains being discovered to what it means to be a geek and using crowd sourcing to deal with disasters

Some of the ideas I want to cover in new episodes include a visit to HARS, a local Air Museum with some really fascinating exhibits, the recent controversy over Amnesty Internationals new approach to sex workers rights and the idea that we've already gone past the point of no return with regards to AI controlled weapons systems.

Then there's For Science. With Magdeline Lum and Maia Sauren, then Mel Thompson, we covered everything from Space Archeology to Salami made from infant bacteria and How not to science.

I want to start podcasting about science again. Since the last episode of For Science I've tried to keep things up with #lunchtimescience but I miss the audio production side of things and I really miss the back and forth that we had going. I'm planning on dipping my toes back into the water with a weekly Lunchtime For Science podcast. This will be a shorter format, coming at the end of each week to summarise the news and hopefully introduce a couple of new segments.

And finally there's WTF Australia. Not sure what to do about this one. Bernie and I had a lot of fun doing the weekly hangouts but at the end we just sort of drifted. 

So as you can see, all the plans, just a lack of the ability to get over the blockage.

Blog Catagories: angrybeanie

Sridhar Dhanapalan: Twitter posts: 2015-08-10 to 2015-08-16

Mon, 2015-08-17 01:27

Peter Lieverdink: Exploring the solar system

Sun, 2015-08-16 22:27

At last week's telescope driver training I found out that Melbourne contains a 1 to 1 billion scale model of the solar system. It's an artwork by Cameron Robbins and Christopher Lansell.

The Sun is located at St Kilda marina and the planets are spaced out along the beach and foreshore back towards the city.

Since the weather was lovely today, I thought ... why not? The guide says you can walk from the Sun to Pluto in about an hour and a half, which would make your speed approximately three times the speed of light, or warp 1.44, if you like.


The Sun. It's big.

Mercury, 4.9mm across and still at the car park, 58m from the Sun.

Venus, 1.2cm across on the beach at 108m from the Sun.


Earth (1.3cm) and Moon (3.5mm) are on the beach as well, at 42m from Venus (and 150m from the Sun).

Mars is 6.8mm across and at the far end of the beach, 228m from the Sun.

The walk now takes you past the millions of tiny grains of sand that make up the asteroid belt and the beach.

Jupiter is 14cm across and lives 778m from the Sun, near the Sea Baths.

The outer solar system is rather large, so it would be wise to purchase an ice cream at this point.

Saturn (12cm, rings 28cm) is nearly twice as far away from the Sun at 1.4km near St Kilda harbour as Jupiter was.

Uranus (5cm) is so far from the Sun (2.9km) that it's actually in the next suburb, near the end of Wright Street in Middle Park.

Neptune (4.9cm) is in the next suburb again (Port Melbourne) at 4.9km from the Sun.

No longer a planet, but still included. Pluto is a 2mm pellet on the beach at Garden City (yet another suburb along again) at 5.9km from the Sun.


On this scale, the nearest star (Proxima Centauri, an uassuming red dwarf) is about 40 trillion kilometers away from the sun. Which, on a one to billion scale, happens to be about the same as once around the Earth. 


Proxima Centauri is just on the other side of the Sun from the rest of the solar system, a cool 4.2 light years away.


Google map of the Melbourne solar system.

Tags: astronomymelbourne

Linux Users of Victoria (LUV) Announce: LUV Main September 2015 Meeting: Cross-Compiling Code for the Web / Annual General Meeting

Sun, 2015-08-16 19:30
Start: Sep 1 2015 18:30 End: Sep 1 2015 20:30 Start: Sep 1 2015 18:30 End: Sep 1 2015 20:30 Location: 

6th Floor, 200 Victoria St. Carlton VIC 3053



• Ryan Kelly, Cross-Compiling Code for the Web

• Annual General Meeting and lightning talks

200 Victoria St. Carlton VIC 3053 (formerly the EPA building)

Before and/or after each meeting those who are interested are welcome to join other members for dinner. We are open to suggestions for a good place to eat near our venue. Maria's on Peel Street in North Melbourne is currently the most popular place to eat after meetings.

LUV would like to acknowledge Red Hat for their help in obtaining the venue and VPAC for hosting.

Linux Users of Victoria Inc. is an incorporated association, registration number A0040056C.

September 1, 2015 - 18:30

read more

Rusty Russell: Broadband Speeds, New Data

Sat, 2015-08-15 16:02

Thanks to edmundedgar on reddit I have some more accurate data to update my previous bandwidth growth estimation post: OFCOM UK, who released their November 2014 report on average broadband speeds.  Whereas Akamai numbers could be lowered by the increase in mobile connections, this directly measures actual broadband speeds.

Extracting the figures gives:

  1. Average download speed in November 2008 was 3.6Mbit
  2. Average download speed in November 2014 was 22.8Mbit
  3. Average upload speed in November 2014 was 2.9Mbit
  4. Average upload speed in November 2008 to April 2009 was 0.43Mbit/s

So in 6 years, downloads went up by 6.333 times, and uploads went up by 6.75 times.  That’s an annual increase of 36% for downloads and 37% for uploads; that’s good, as it implies we can use download speed factor increases as a proxy for upload speed increases (as upload speed is just as important for a peer-to-peer network).

This compares with my previous post’s Akamai’s UK numbers of 3.526Mbit in Q4 2008 and 10.874Mbit in Q4 2014: only a factor of 3.08 (26% per annum).  Given how close Akamai’s numbers were to OFCOM’s in November 2008 (a year after the iPhone UK release, but probably too early for mobile to have significant effect), it’s reasonable to assume that mobile plays a large part of this difference.

If we assume Akamai’s numbers reflected real broadband rates prior to November 2008, we can also use it to extend the OFCOM data back a year: this is important since there was almost no bandwidth growth according to Akamai from Q4 2007 to Q7 2008: ignoring that period gives a rosier picture than my last post, and smells of cherrypicking data.

So, let’s say the UK went from 3.265Mbit in Q4 2007 (Akamai numbers) to 22.8Mbit in Q4 2014 (OFCOM numbers).  That’s a factor of 6.98, or 32% increase per annum for the UK. If we assume that the US Akamai data is under-representing Q4 2014 speeds by the same factor (6.333 / 3.08 = 2.056) as the UK data, that implies the US went from 3.644Mbit in Q4 2007 to 11.061 * 2.056 = 22.74Mbit in Q4 2014, giving a factor of 6.24, or 30% increase per annum for the US.

As stated previously, China is now where the US and UK were 7 years ago, suggesting they’re a reasonable model for future growth for that region.  Thus I revise my bandwidth estimates; instead of 17% per annum this suggests 30% per annum as a reasonable growth rate.

Leon Brooks

Sat, 2015-08-15 12:51
In this case, it was similar to having the garbage dispose of itself... except for the kidnappees also taken and reprogrammed into psychopathy, as was done to the kidnapper when they were an infant.

Gary Pendergast: The Basics: The Age of Entitlement

Fri, 2015-08-14 14:26

The first new album from The Basics in several years, and it’s a good ‘un.

They’ve been making use of their time off – Wally became an international star as Gotye, Kris spent 2 years working in Kenya with the Red Cross, and both Tim and Kris ran for parliament in the recent Victorian state election.

Now, mix those experiences together, you have an idea of what’s on the new album. A combination of politically aware rock, both locally focussed 1 with Whatever Happened To The Working Class?, globally focussed with Tunaomba Saidia; and some Gotye-esque pop such as Good Times, Sunshine!.

Anyway, listen to it now below, then go out and buy it.

  1. Is it too much to call them a modern Midnight Oil? I don’t think so.

Matt Palmer: Your "Infrastructure as Code" is still code!

Thu, 2015-08-13 15:46

Whether you’re a TDD zealot, or you just occasionally write a quick script to reproduce some bug, it’s a rare coder who doesn’t see value in some sort of automated testing. Yet, somehow, in all of the new-age “Infrastructure as Code” mania, we appear to have forgotten this, and the tools that are commonly used for implementing “Infrastructure as Code” have absolutely woeful support for developing your Infrastructure Code. I believe this has to change.

At present, the state of the art in testing system automation code appears to be, “spin up a test system, run the manifest/state/whatever, and then use something like serverspec or testinfra to SSH in and make sure everything looks OK”. It’s automated, at least, but it isn’t exactly a quick process. Many people don’t even apply that degree of rigour to their system config systems, and rely on manual testing, or even just “doing it live!”, to shake out the bugs they’ve introduced.

Speed in testing is essential. As the edit-build-test-debug cycle gets longer, frustration grows exponentially. If it takes two minutes to get a “something went wrong” report out of my tests, I’m not going to run them very often. If I’m not running my tests very often, then I’m not likely to write tests much, and suddenly… oops. Everything’s on fire. In “traditional” software development, the unit tests are the backbone of the “fast feedback” cycle. You’re running thousands of tests per second, ideally, and an entire test run might take 5-10 seconds. That’s the sweet spot, where you can code and test in a rapid cycle of ever-increasing awesomeness.

Interestingly, when I ask the users of most infrastructure management systems about unit testing, they either get a blank look on their face, or, at best, point me in the direction of the likes of Test Kitchen, which is described quite clearly as an integration platform, not a unit testing platform.

Puppet has rspec-puppet, which is a pretty solid unit testing framework for Puppet manifests – although it isn’t widely used. Others, though… nobody seems to have any ideas. The “blank look” is near-universal.

If “infrastructure developers” want to be taken seriously, we need to learn a little about what’s involved in the “development” part of the title we’ve bestowed upon ourselves. This means knowing what the various types of testing are, and having tools which enable and encourage that testing. It also means things like release management, documentation, modularity and reusability, and considering backwards compatibility.

All of this needs to apply to everything that is within the remit of the infrastructure developer. You don’t get to hand-wave away any of this just because “it’s just configuration!”. This goes double when your “just configuration!” is a hundred lines of YAML interspersed with templating directives (SaltStack, I’m looking at you).

Gary Pendergast: Developer On Fire

Thu, 2015-08-13 00:27

I recently had a chat with Dave from Developer On Fire. We talked about a bunch of things – what I work on, how I got started in programming, as well as some thoughts on remote working and maintaining a healthy work/life balance.

The post is here, or you can listen to the audio below.

David Rowe: A Miserable Debt Free Life

Wed, 2015-08-12 17:30

I have a lifestyle that is different to many people, and I have been encouraged to write about it. According to my friends, I am “living the dream”. I get up in the morning and can choose to do anything I want. I don’t work for money any more. I’ve been able to do this since I was 38 (I’m 48 now). I don’t appear to want for anything (material).

This is not a HowTo on retiring young, just a little about my story. Use it as a source of ideas.

Ten years ago I had an executive job in the sat-com industry, and prior to that I had a moderately successful small business, and a stint in academia. Although I was an effective manager, small businessman, and engineer, I was consistently dissatisfied. I did enjoy some parts of these jobs: Digital Signal Processing (DSP), open source, helping people, engineering, teaching thereof, annoying my managers, doing coffee and extremely long pub lunches. Rather than knuckle under and be a good corporate lad I decided to to focus on what I enjoyed most. Especially the coffee and pub lunches.

So I quit corporate life to be a full time “hacker”. I use the term hacker in the positive sense: I develop clever technology. Then, rather than using it to make a profit, I give the technology away in the hope that it will help people. I’ve had some success at this goal over the last 10 years.

My corporate wardrobe is now my pajamas. I spend most of the day sitting on my couch (thanks Dave for the couch BTW!) hacking on my laptop, with daily forays on my bike to a cafe by the beach. This gets me exercise, some social connection, and caffeine.

Once a month I travel interstate to a friends house, borrow their bike, cook for them, and sit on their couch and hack. Mixing a bit of travel with my “work”.

At the moment I average 6 hours of real, focused, head over the laptop work a day. Which is the equivalent of 2 days in a “real job” where you have meetings, managers to annoy, and pub lunches to attend.


  • In my final years of corporate life I listened to podcasts about using technology to help people by a guy called David Bornstein. This idea was quite appealing, a good use of my skills.
  • At the same time a couple of friends (Scott and Horse) put the idea in my head of lifestyles not aimed merely at continual material accumulation. One of them had paid off his house but didn’t see any reason to “upgrade” with more debt; the other just bailed on an engineering career to play volleyball and guitar, living off his savings for a bit. Huh? I found myself admiring them.
  • Volunteer work my Father did for disabled people.
  • A book called Affluenza by Clive Hamilton, which deals with our growing addiction to materialistic lifestyles.
  • Travel. Especially to the developing world, Timor Leste, India, townships in South Africa.

But How Do You Get Money to Live?

Money you need = income – how much you spend.

I live frugally, but am always happy to spend money on my kids (for stuff they really need) or entertaining friends. Most nights I dine in rather than going out, and can cook a bunch of meals in 10 minutes that feed 4 people for $10.

My living costs (including food, bills, housing, schooling, medical, transport) are about $40,000/pa, before any discretionary purchases like new IT or holidays. That is for a household of 2.5 people (I share care of one child).

I drive an electric car which costs very little to drive and maintain, which I supplement with the occasional loan/rental of petrol cars.

My kids go to public schools; my peers spend up to $40k/year on private education. I am home every day for them when school ends, can help them in almost any subject (although they never ask of course as I am their Dad), and attend every interview to monitor their progress at school.

I am not convinced there is any significant advantage from private schools, but acknowledge the emotional buttons and peer group pressure around private education is strong for many parents. My kids are doing pretty well, e.g. one at University, another getting good grades at the best science and maths school in the state.

I get income from a variety of sources, but the total is rather low compared to my peers. And that’s OK. Currently there is some income from SM1000 sales. In the past it’s been from VOIP products like the IP0X VOIP systems and a little contract work. I have some passive income from shares, enough to cover my rent. So it’s a bit like owning my home. These shares have been accumulated over 20 years simply by saving and reinvesting. No get rich quick schemes here.

Planning is good if you want to get somewhere. Here is a simple financial plan, start with $10k, start saving $100/week (5% more every year), invest at 10% (you get to work out where). Repeat for 20 years and you have enough to buy a house, or generate some passive income. Yes I know it doesn’t include inflation, and returns vary over time, blah, blah, blah. Your turn – come up with a model that does include these factors.

In Australia the government gives much of the population “middle class welfare”, a few $100/week which covers much of my food and bills. We also have free public health care. So the country you live in helps. On the down side the houses here are really expensive to buy, an average of $500,000 (10 years average income), and public transport poor. Every country has it’s pros and cons.

I have modest financial skills and good habits. Primarily the ability to spend less than I earn and avoidance of debt. I use a trusted share broker to choose conservative shares, but I decide the overall strategy. Some people like real estate for investment, it doesn’t really matter.

Saving and time is the key. Conversely if you can’t save, it doesn’t matter if you earn $200k. At the end of your time you will have nothing but a pile of debt, useless possessions, an endless need to work hard, broken relationships, and stress.

Every few years I go without income and live off savings for 12 months while I develop a new product. Living off savings for a while has ceased to worry me. However I understand most people are 1 pay cheque away from serious financial trouble. How about you? How long could you live without a pay cheque? It’s a good check on your financial health.

Effective Altruism

I’ve recently realised that working for free to help people is a form Altruism. So instead of traveling to a village to help less fortunate people I’d like to invent a widget (or part of a widget) that might let 1000′s of villages communicate. Or something like that. At the moment I’m focused on digital voice over HF radio that has many applications, e.g. in humanitarian and remote communications. I’m inventing technology building blocks that let me help the world a little bit, and stretch my professional skills (it’s post doctoral R&D in my field of signal processing).

Now, if you can name an enterprise, you can engineer it. Use numbers to make it better.

So, I’m currently reading a book called The Most Good You Can Do by Peter Singer. This guy is applying a numerical framework to “Effective Altruism”. Engineering it. For example he calculates the impact of donating a kidney (really!), or saving a persons life with $x versus preventing blindness in 10 people with the same $x. Is it better to work for 200k and donate 150 to a charity, or work for 50k in the same charity? Quite an easy to read book, but some fascinating ideas.


I have to think carefully and be sensitive to connect with the life of people with “real jobs”. When my friends head off to work every day, it’s a mental shift for me to understand. Yes I understand we need to be fed and housed. However I note a large portion of this work seems to be around paying for things we don’t really need, or making minimum payments on enormous debt. Wage slavery? But hey, my bank shares keep going up, and the dividends keep getting bigger, so who I am to question this system!

Until age 38 I was very focused on material accumulation. I had a Porsche 911 (called Helmut), several investment properties, a wife, and several pairs of trousers. At that stage I just ran out of things to buy. That was disconcerting for someone who came of age in the 1980′s. It felt, inexplicably, like a miserable debt free life. So I had a bit of a think. It’s taken me a little while to shift my attitude to money, however I am gradually letting go. Old habits die hard. I still feel bad when not saving and accumulating.

Re money all you need is the ability to save and time. Many people seem compelled to piss every cent they get down the drain. This is encouraged by the “growth paradigm” that governments push, easy debt, materialism, and lack of financial literacy.

Here is how I’m making my kids rich. It’s working too – they are in a better position than I was at their age and a million miles ahead of their peers. Or for that matter a lot of people my age (30 years older than them). It’s not just their net worth either: I get them involved, building their skills in handling money and investing. Showing a 9 year old a dividend statement. Getting a 17 year old to build a spreadsheet predicting growth of his assets over 10 years. Giving a child part of my web business to run. Making them wait for new material possessions. Not giving them everything they want, of that their friends have. Forming good habits early.

I struggle with the idea of debt for non-essential items, or huge, barely serviceable debt that is impossible to pay down quickly. Certainly not for a bigger house or a $500 outfit or gadgets “paid” for on a credit card. Or strongly depreciating items like cars (unless it’s electric of course). Useless debt turns the financial model above on it’s head. If you waste $100/week now YOU get to pay the banks $500k over 20 years. Then go back to work to do it again for another 20!

I am very fortunate and feel I must help others with my good fortune. We are all going to die one day. Everything that matters to us, everything we ever owned, every problem we have – will all be dust. Quickly forgotten, after a few kind words at your funeral. However helping improve the lives of others matters. That can endure. I can’t imagine a life where I am not helping others. Working just for more toys or my own needs is not enough.

So now I’m going to sit on my couch, do some hacking, then give it away.

And no – you are not going to see me in my PJs!

Reading Further

A Miserable Debt Free Life Part 2