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Linux Users of Victoria (LUV) Announce: LUV Main December 2015 Meeting: Maxima / holiday gifts

Thu, 2015-11-26 15:29
Start: Dec 1 2015 18:30 End: Dec 1 2015 20:30 Start: Dec 1 2015 18:30 End: Dec 1 2015 20:30 Location: 

6th Floor, 200 Victoria St. Carlton VIC 3053

Link:  http://luv.asn.au/meetings/map

Speakers:

• Chelton Evans, Maxima

• Andrew Pam, Holiday gift suggestions for Linux lovers

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

Late arrivals, please call (0490) 049 589 for access to the venue.

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.

December 1, 2015 - 18:30

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linux.conf.au News: LCA2016 Optiver Diversity Programme Announced

Tue, 2015-11-24 19:28
linux.conf.au 2016, in partnership with Optiver, are very proud to announce our diversity programme for 2016! LCA2016 and Optiver are proud to be able to support diversity in our community. The Optiver Diversity Programme is intended to ensure that linux.conf.au continues to be a safe, open, and welcoming conference for everyone. Together with Optiver the programme has been developed to assist delegates from under-represented cohorts who contribute to the Open Source community but, without financial assistance, would not be able to attend LCA2016. For more information please see our Optiver Diversity Programme page

David Rowe: SM2000 Part1 – Open VHF Digital Voice Radio

Tue, 2015-11-24 09:30

For the last month I’ve been working hard on prototyping the SM2000 – an open source VHF radio. It’s purpose is to test some advanced VHF/UHF ideas I have for FreeDV.

The SM2000 will be a small box (like the SM1000), that contains a fully functional VHF SDR Digital Voice radio. It will run advanced open source Digital Voice modes, have a 1W power output and adequate tx/rx filtering for real-world operation on the 2M band. No Host PC required. Open Hardware and Software, price TBD but a few hundreds of $. It will also run analog FM but no modes with a proprietary codec.

Just yesterday I demonstrated demodulation of 1200 bits/s 2FSK at -135dBm, right in line with predicted performance.

This is an important milestone. Analog FM and first generation digital voice (D-star/DMR/C4FM and friends) fall over at about -120dBm. One of my aims is equivalent performance to these systems at 10dB lower. With completely open hardware and software.

Requirements

I need custom RF hardware to develop and demonstrate VHF DV ideas I have formed over the past year. However I am not a RF expert, am just one guy, and have limited resources. So I will focus on those areas that I can uniquely contribute to. Choose my battles. In other areas (e.g. certain aspects of RF performance), I will just shoot for acceptable.

I have a similar approach to architecture. There are many ways to build a radio, and I have chosen one that suits me at this time. Feel free to warm up your soldering iron and substitute your own favourite.

What I care about:

  • I don’t trust any part of the modem being in hardware. This means software defined waveforms, and SSB style up and down conversion. Direct FM is out. And don’t get me started on data running through analog FM modems.
  • TDMA needs a “bare metal” uC for hard real time, so no OS. Host PC/USB peripheral type designs won’t work.
  • Functional demos of advanced features such as sub -130dBm Digital Voice, $100 TDMA repeater, diversity to handle multipath, low cost, open hardware and software.
  • No chip sets or SoCs. This is open source. I need control.
  • Don’t have to a tick all boxes first time around.

Less important:

  • Minimal cost
  • Sparkling RF performance in areas such as phase noise, IP3, blocking, ACR, high tx power, frequency stability, channel spacing, multi-band operation, low spurious, power consumption. The RF Gurus can do that better than me so I’ll leave it to them.
  • Gold plating – is the feature going to add to our schedule? Can anyone else implement it? Will it introduce risk? Who will step up to make it happen?

Your Suggestions Welcome

But I’ll probably ignore them. What I really want is your contribution. If you want your-favourite-must-have-feature to happen, step up and make it happen. Innovation is 1% inspiration and 99% perspiration. I get overwhelmed by well-meaning people with inspired ideas, and underwhelmed when I ask them to help implement those ideas.

Can you make my TODO list shorter, not longer? Now you have my attention.

Receiver Design

The receiver is a dual conversion superhet, with IFs at 10.7MHz and 24kHz. It is designed primarily for constant amplitude waveforms such as FSK, so does not have an AGC.

I used this Gain and Noise Spreadsheet as a tool to design the radio. It calculates cascaded NF, the NF of the ADC, and the gain required to get the MDS we need. I also have some sub-sections that I plug numbers into as I test, e.g. for NF calculations, and tuned circuit calculations. Very useful.

I haven’t designed the first BPF yet, but anticipate it will have a low loss (to maintain system NF), and a fairly broad response.

The PGA103 is a 0.5dB NF, 20dBm input IP3, 20dB gain block which sets up the overall receiver noise figure of 1.5dB. It’s major disadvantage is high power consumption (90mA at 5V), so I am considering a discrete transistor amplifier here.

The BPF near the mixer provides attenuation of out of band signals. Through a process of slightly mystified experimentation I have settled on a double tuned circuit:

Which has a response like this:

For reasons I do not understand (parasitic capacitive coupling?) changing the position of the coils relative to each other sets the position of the notches. I’ve set up the 60dB notch on the 126MHz image frequency. I’ve built it a couple of times with the same dimensions and the response is quite predictable. Each coil is 6 turns wound on a 1/4 inch drill bit, with a tap at half a turn for the 50 ohms input and output. The other end of each coil has a 12pF trimmer cap.

A Si5351 is employed for the local oscillators. For the purists I will include a Si570 option for the first LO. The RF switch for the two Si5351 outputs is to support diversity (two channel) reception. The radio can quickly shift to a channel a few hundred kHz away to receive a packet, effectively receiving on two frequencies at the same time.

I’m using a SBL-1 mixer but will move to an ADE-1. The RF Gurus tell me that termination of the IF port of the mixer is important. So I’m using a 15dB gain Termination Insensitive Amplifier (TIA) that presents a 50 ohm load to the mixer over a wide range of frequencies. I swept the TIA input using a return loss bridge and confirmed around 20dB return loss out to 300MHz (the sum of the LO and RF signals). The TIA has bandwidth of 50MHz which should effectively filter out the LO+RF IF signal.

A 10.7MHz 15kHz wide crystal filter attenuates off channel signals (47dB down at +/- 25kHz) and performs bandpass anti-aliasing filtering for the ADC. To get a nice flat response there is some impedance matching either side of the crystal filter.

I messed around with a few 2nd mixers (sub harmonic, discrete transistor, diode). I had some problems with noise when using a transistor mixer (LO injected into emitter, RF into base) which held me up for a few days. Then I tried a NE602 and it worked really well, and provides some gain. With a good Z-match on the input the 2nd mixer noise problem was gone. So that will do for now.

The baseband amp takes the 24 kHz IF and boosts it 50dB before feeding it to the uC ADC. It’s just two transistors with emitter degeneration to set the gain. The ADC is configured to sample at 96kHz, and upload samples to a Host PC via USB. I can then use a GNU Octave script (e.g. fsk_horus.m) to demodulate the FSK signal.

Testing

I am designing for test, e.g. using 50 ohm building blocks. This allows me to break out each section and test separately, for example sweeping the crystal filter, or driving the TIA with a 10.7MHz FSK signal, or measuring NF of a section.

I have been testing the Bit Error Rate (BER) performance from the very early building block stage. This measure neatly defines the performance of a digital radio. Much better to test BER early than wait for final integration and have dozens of problems to solve. We want to know as soon as possible if there is a problem.

This block diagram shows an example of testing from the IF down:

I modified the fsk_horus modem to support 1200 bit/s and a sample rate of Fs=96kHz. This is a well tested modem that has performance bang on ideal.

Component Selection

The radio is implemented with garden variety transistors, the most exotic parts being the ECS M15B crystal filter, SBL-1 mixer, PGA-103 LNA, and NE602. There are no transformers. I have used some toroids to wind my own inductors however these are not critical in terms of Q or tolerance and can be replaced with off the shelf parts.

There are three trimmer capacitors that need aligning with the use of a spectrum analyser. Although it may be possible to have an alignment mode, e.g. use the Si5351 to sweep a test signal, sample the signal and display a spectrum on a Host PC.

I used Manhattan style construction:

The two PCBs in the background are a STM32F4 Discovery board and an OpenRadio which I’m just using for it’s Si5351 outputs.

I didn’t even need a printed circuit board to prototype and reach the -135dBm performance milestone. This has allowed me to remove a large chunk of risk from the project very early on – a huge benefit.

I think it’s remarkable that with rough construction, no shielding, a poor layout to the STM32F4 ADC, I can demodulate such weak signals. I guess the engineering is subtle and not related to the physical appearance. It does go crazy when I key my HT next to it though!

When we do move to a PCB the same parts in surface mount packages will result in a nice compact design.

Next Steps

  • Build a 1W transmitter prototype. In particular deal with RF amplifiers and diode switching to make a TDMA transciever.
  • Testing of the receiver, e.g. other specs apart from MDS
  • Work with Rick, KA8BMA, to develop a Rev A prototype PCB version of the entire radio.
  • Lots of software work
  • The 1200 bit/s 2FSK modem has been used so far as it’s what I had lying around. For the final system I’m favouring 4FSK at 2400 bit/s which I estimate will work at -132dBm. So need to get 4FSK running soon.
  • Work towards functional demonstration of the project goals.

I haven’t planned any further forward. I’m not sure when a SM2000 product will emerge. Some time in 2016 I guess. Sooner if you help!

Command Lines

I’m documenting this here so I don’t forget.

Use fsk_horus to generate modem signal at Fs=96kHz. Use hackrf_uc.m to up-convert to IQ samples at Fs=10MHz for replay by the HackRF. hackrf_uc.m also adds a 700kHz offset (IQ designs have a black hole at DC).

For testing the IF we can then play a 10.7MHz signal from HackRF using:



/codec2-dev/octave$ hackrf_transfer -t fsk_10M_EbNo80dB.iq -f 10000000 -a 1 -x 20

For testing at 146MHz input of the radio use:



~/codec2-dev/octave$ hackrf_transfer -t fsk_10M_EbNo80dB.iq -f 145300000 -a 0 -x 15



Note the 700kHz offset.

In both cases adjust the -a and -x options and use an attenuator to get the level you want for testing. The level can be checked on a spec-an, although this gets tricky beneath -120dBm.

Simultaneously sample by flashing the STM32F4 Discovery with adc_rec_usb.elf, and then upload Fs=96kHz samples using:



~/codec2-dev/octave$ sudo dd if=/dev/ttyACM0 of=test.raw count=10000

Then demod using fsk_horus:



octave:109> fsk_horus

Fs: 96000 Rs: 1200 Ts: 80 nsym: 1200

demod of raw bits....

centre: 23976 shift: 1272 twist: -1.4 dB

coarse offset: 1192 nerrs_min: 25 next_state: 1

plotting...

frames: 13 Tbits: 14400 Terrs: 2 BER 0.000 EbNo: 12.23

Here is a plot of the STM3F4 ADC with -135dBm at the rx input:

You can see the passband of the crystal filter – the internal noise from the radio front end passed through the filter creates the trapezoidal spectral shape at the input to the ADC. The two lines in the centre are the low and high FSK tones centered on the 24kHz IF, the hump of “noise” between them are part of the FSK signal. Not sure what that line around 17kHz is all about.

The lines on the far left are harmonics of the 1.2kHz interrupt service routine on the STM32F4. I cleaned most of this noise up with some power supply filtering, it was initially 20dB higher and all over the spectrum:

A little noise goes a long way with 100dB of gain.

Measuring Noise Figure with the Rigol DSA-815

After lots of reading on NF and a few false starts, I can now reliably measure noise figures, e.g. in my LNA, mixer, BPF, and IF amplifiers. For example the TIA amplifier NF is quoted as 5 dB and I measured 5.2dB. I have also measured the single (BPF in front) and double sided NF of the SBL-1 mixer and they were 3dB apart.

You need to have noise above the noise floor of the 815. With the 815 terminated in 50 ohms I measured -162dBm/Hz, which suggests a NF of 12dB. With gains of greater than 20dB on the device or system you are measuring, the numbers from the 815 start to make sense. So plan your tests such that the measured No is higher than -140dBm/Hz.

Here are the Rigol settings I use:

  1. Amplitude: attenuation 0dB. Pre-amp On
  2. BW/Det: sample
  3. Trace/P/F: Power average
  4. Marker Function: No function (to measure gain) Noise Marker (to measure No)

The procedure is: measure the gain G using a test signal, then switch the test signal off, terminate with 50 ohms, and measure No (noise power/Hz). NF = No – G + 174.

Here is my working for an earlier LNA-Mixer-IF amp combination:



Input power  -80.00

Output power -10.00

Gain          70.00

Noise pwr   -102.20  

NF             1.80

My design had a calculated NF of 1.3dB, so 1.8dB is reasonable given the 1.5dB accuracy of the 815. I have a spreadsheet setup so I can just plug the numbers in.

Thanks

Mel K0PFX, and Jim, N0OBG for buying me the spec-an, which has been invaluable. Neil, VK5KA, for RF advice; John VK3IC and Craig VK3CDN for cables, test equipment, and RF advice; Matt, VK5ZM and Brady for bouncing ideas off; Glen English for RF guidance and in particular explaining ADC NF.

Brady pointed me at the DSP10 2M radio from 1999 which turns out is very similar to what I have come up with! Some very similar design decisions, and a useful example for me.

Sam Watkins: sswam

Mon, 2015-11-23 18:30

I like the Chrome browser, but the memory usage is fscking ridiculous.

I have a slightly older computer at work, if I open 4 or more tabs in Chrome the computer will grind to a halt, and I gotta wait perhaps a few minutes for it to swap everything out then I can close the tabs. 150MB for a tab, that’s just way way way too much.

Personally I strongly dislike “virtual memory” in the sense of swapping to disk. I’d much rather get a (non-fatal) “out of memory” error than have the computer grind to a halt, which is what happens when a virtual memory computer goes a bit over its RAM. I don’t want to click a different window that I haven’t used for a while and have to wait for 3 minutes while the computer loads it from disk again and tries to figure out what to swap out. If we didn’t use swap, programmers (looking at you, Google) would be more careful not to waste memory.

Computers are not all that much more functional than they were in to 1990s, or even the 1980s, for regular office tasks such as wordprocessing and spreadsheets – and those computers although technically slower were actually more responsive in many cases because they did NOT grind to a halt due to swapping.

</rant>



OpenSTEM: The Robots Are Coming!

Mon, 2015-11-23 18:30

The first Mirobot v2 kits have arrived in Australia! Ben Pirt at Pirt Design & Technology in the UK has once again delivered a very neat product. OpenSTEM is the main distributor for Australia, because we regularly get in quite a few for schools and individual students anyhow.

Most of our Mirobots are extra special, because we get them un-soldered. That is, there are a few SMD (surface mounted) components, but other than that students (of all ages!) can do a bit of soldering! This is part of our Robotics Program, where Soldering and otherwise assembling a moving product from all the loose parts is a real enabler – so with the v2 coming out in pre-soldered form by default, we had a word with Ben to ensure that we can keep doing the great stuff with the classes!

This does mean that for every shipment we get, we need to prep a few extra bits before sending on the kits or using them in the classroom. So we’re working on that now for this first shipment. There’ll be more – if you want a kit (un-soldered or pre-soldered), do get your order in soon!

linux.conf.au News: Crowd favourite Bacon to headline linux.conf.au

Mon, 2015-11-23 07:28

Newly-appointed Director of Community at GitHub, Jono Bacon, will be one of four outstanding keynotes for linux.conf.au in February 2016. Bacon, formerly Community Manager at Canonical - the company behind Linux distribution Ubuntu, and author of the best-selling ‘The Art of Community’, will deliver insights into building strong, effective, diverse and successful technical communities.

Bacon shared his enthusiasm for keynoting linux.conf.au. “I am absolutely delighted to be joining you all in Geelong in 2016. LCA is a cornerstone in the global Linux and Open Source movement and I am not only excited about speaking but also getting to know all the attendees at the event”, Bacon says.

Conference Director, David Bell, was thrilled to announce Mr Bacon as Keynote Speaker.

“Our theme for linux.conf.au 2016 is ‘Life is better with Linux’ - and the strength of our Linux and open source communities contribute significantly to that aspiration. Robust, diverse, and inclusive communities happen by design, not accident, and Jono has done an enormous amount to shape that. It’s truly an honour to be able to host him in Geelong in February.”

One of the most respected technical conferences in Australia, Linux Conference Australia (linux.conf.au) will make Geelong home between 1st-5th February 2016. The conference is expected to attract over 500 national and international professional and hobbyist developers, technicians and innovative hardware specialists, and will feature nearly 100 Speakers and presentations over five days. Deakin University’s stunning Waterfront Campus will host the conference, leveraging state of the art networking and audio visual facilities.

The conference delivers Delegates a range of presentations and tutorials on topics such as open source hardware, open source operating systems and open source software, storage, containers and related issues such as patents, copyright and technical community development.

Linux is a computer operating system, in the same way that MacOS, Windows, Android and iOS are operating systems. It can be used on desktop computers, servers, and increasingly on mobile devices such as smartphones and tablets.

Linux embodies the ‘open source’ paradigm of software development, which holds that source code – the code that is used to give computers and mobile devices functionality – should be ‘open’. That is, the source code should be viewable, modifiable and shareable by the entire community. There are a number of benefits to the open source paradigm, including facilitating innovation, sharing and re-use. The ‘open’ paradigm is increasingly extending to other areas such as open government, open culture, open health and open education.

Potential Delegates and Speakers are encouraged to remain up to date with conference news through one of the following channels;

  • Website: http://lcabythebay.org.au
  • Twitter: @linuxconfau, hashtag #lca2016
  • Facebook: https://www.facebook.com/lcabythebay
  • Google+: https://www.google.com/+LcabythebayOrgAu
  • Lanyrd: http://lanyrd.com/2016/linuxconfau/
  • IRC: #linux.conf.au on freenode.net
  • Email: info@lcabythebay.org.au
  • Announce mailing list: http://lists.linux.org.au/mailman/listinfo/lca-announce

We warmly encourage you to forward this announcement to technical communities you may be involved in.

Jono Bacon will be one of four keynotes for linux.conf.au 2016 in Geelong

Binh Nguyen: How Wasteful is the US DoD?, How Groundbreaking is the JSF?, and More

Mon, 2015-11-23 02:04
It's clear that I've been doing some digging of late with regards to US DoD and Intelligence spending. What's obvious is that large chunks of it are extremely wasteful but other parts are very underfunded which gives a very bad overall look to it. Some ex-defense/intelligence officials have stated that if they could run things more efficiently they could probably halve their spending and still

Sridhar Dhanapalan: Twitter posts: 2015-11-16 to 2015-11-22

Mon, 2015-11-23 01:27

Steven Hanley: [mtb] Brinzio loop and Summit Fiore ride

Sun, 2015-11-22 20:25


Looking over from the observatory to the Fiore summit (fullsize)

Though I had headed out solo to ride Basso Binda on the first Sunday I was there this ride I got to do with some company until the last climb and get shown one of the classic loops in the region.

My first views of Lago Maggiore and then back through Brinzio, then when we got back to Varese I decided to solo climb up to the summit past the Campo di Fiore and into the snow that was still around from the falls on the weekend. A rather pretty area for sure.

Images in my gallery from the ride ETC, Varese, Brinzio, Lago Maggiore, Brinzio, Summit Fiore ride.

Steven Hanley: [mtb] Alpe di Neggia ride in Italy/Switzerland

Fri, 2015-11-20 13:26


Looking toward Switzerland from the top of the climb (fullsize)

I had a work trip to the European Training centre in Gavirate Italy in April 2012, while there I managed to get out for three rides and one solid run. On the rides I took my camera and was able to get some great shots. Definitely an awesome area to train in for many sports.

Recommended to me by Luke Durbridge who was at the ETC while I was there, this ride was from Gavirate over to Lago di Maggiore and then along the shores until I hit the climb and down the other side in to Switzerland than back through the valley past Lago di Lugano toward the border at Ponte Tresa above Varese. A great ride for sure and a nice climb, though I probably left it an hour too late as coming back it was dark by the time I got to Varese and I had not taken lights.

Images in my gallery from the ride Alpe di Neggia ride in Italy/Switzerland.

OpenSTEM: RCA Old Technology Video (1983)

Fri, 2015-11-20 11:29

It’s cool to look at past visions of the future, particularly those from companies in a sales/marketing context because they contain all the fabulous buzzwords from the time.

Entitled RCA Video Monitors: The Future Is Now (1983), the below is a segment from an extremely rare CED videodisc sent to dealers telling them about the then new concept in TV design: the inclusion of multiple A/V inputs and outputs for connecting multiple devices!

(image by grm_wnr, Wikimedia)

The intermittent skipping you see on the video was “normal” for that videodisc technology. Mind that videodisc wasn’t DVD, videodisks were quite big.

Note that, oddly, DVDs also exhibit a brief skip when (they switch from one layer to another on dual-layer disks). Technically it’d be so easy to avoid this visual annoyance!.

(image by GrahamUK, Wikipedia)

The Compact Disk (CD) was invented by Philips and launched around 1984. DVD (Digital Versatile Disk) is from 1995. Philips actually has a history of these broad innovations, in 1953 they launched the Compact Cassette.

Philips somehow misfired with video recorders (VCRs), adopting the technically superior Video 2000 format (1979), and as we now know VHS became the global standard. The VCR format saga is an interesting historical example of where factors other than purely technical superiority played a role in defining the winner. Among other factors, they came in late – but there was more to it. Anyhow, we know that even Betamax was regarded as superior in quality to VHS, Betamax remained in use for professional recording equipment for a very long time.

Linux Users of Victoria (LUV) Announce: LUV Beginners November Meeting: Security scanning with Nmap

Thu, 2015-11-19 22:29
Start: Nov 21 2015 12:30 End: Nov 21 2015 16:30 Start: Nov 21 2015 12:30 End: Nov 21 2015 16:30 Location: 

RMIT Building 91, 110 Victoria Street, Carlton South

Link:  http://luv.asn.au/meetings/map

Scott Junner will offer a basic run through of the main functions of Nmap with some explanations of the background of what Nmap is doing and why it gets some of the results it gets. He will talk about why you would want to use Nmap and give an example of a few scans he did on his own network to show the kind of information that others could collect. Or you could collect on others - depending on which way you lean.

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

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

November 21, 2015 - 12:30

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Steven Hanley: [mtb/events] Triple Triathlon 2015 - Where's Our Swimmer - Mixed Pairs

Thu, 2015-11-19 22:25


Tagging Milly for the Mt Taylor run (fullsize)

As I mention in the words I ended up in pairs this year again, racing with Milly after our swimmer for the event injured himself. Our goal was to have a fun day out in Canberra looking forward to the finish line and beers there. I think we managed that and enjoyed hanging out with all the others transcending the hills and lakes of Canberra.

Great to see Rowan have so much fun on course again, also Cam had an amazing day out with 12h15m solo and finishing third. Ben Crabb got to race again with his normal team before disappearing to the UK for three years. So many others were having fun and so were Milly and I (though the early shot of her before the swim start she does not appear so sure), looking through the event gallery on the Sri Chinmoy events site there are some good photos of everyone around too.

My words and photos are online in my Triple Triathlon 2015 - Wheres Our Swimmer - Mixed Pairs gallery. Good day out bring on 2016.

Steven Hanley: [mtb/events] Geoquest 2012 - Out Of Range

Thu, 2015-11-19 10:25


Heading into the water with our tubes (fullsize)

When I looked at this album I realised I still have not published or added comments to my 2011 geoquest album. I guess that will be next. For now this was 2012 with Seb, Lee and Eliza up at Forster again. Before Eliza was quite so hooked on MTB near the end of her doing Triathlon we were trying to convince her long silly AR stuff is the best thing ever, I hope we did not scar her too much with the longest event she had ever done.

KV, Ben and Matt were our rather awesome support crew engaging in a bit of speed camping around the region and seeing us come past once in a while, thanks to them for the effort. It was a remarkably hard (well long at least) course this year and though there was no ocean paddling there was a bit of time in the kayaks. The event was a lot of fun as always, though I still need to sort out some of my insulin type and timing issues (as I was reminded this year when I had some lows).

My 2012 Geoquest - Out of Range gallery is online for anyone to have a look, I almost was worried I managed to get a photo of Eliza not smiling, however it appears not to have happened so all is right with the world.

Chris Smart: Changing Jenkins concurrent job token from @ to something else

Wed, 2015-11-18 16:29

Some jobs may fail in Jenkins when running concurrently because they don’t like the @ symbol in the path.

For example, you may get a jobs at something like:

  • /var/lib/jenkins/jobs/cool-project
  • /var/lib/jenkins/jobs/cool-project@2

This can be easily changed to something else, as per the Jenkins system properties page by modifying the -D arguments sent to Java. I’ve changed it to _job_ at the moment.



echo 'JAVA_ARGS="$JAVA_ARGS -Dhudson.slaves.WorkspaceList=_job_"'\

 >> /etc/default/jenkins

systemctl restart jenkins

Now concurrent jobs will be something like:

  • /var/lib/jenkins/jobs/cool-project
  • /var/lib/jenkins/jobs/cool-project_job_2

Which seems much nicer to me.

Steven Hanley: [mtb] Hume and Hovell Ride Albury to Canberra 2012

Wed, 2015-11-18 07:25


A creek crossing on day 1 (fullsize)

This was a really fun ride, 3 days riding from Albury to Canberra on the Hume and Hovell track, a bunch of ARNuts and others, stopping overnight in Tumbarumba and then Tumut.

It was also not long after the Greenedge Call Me Maybe video came out so many of us spent a fiar proportion of the ride posing for photos and some videos miming the actions. I have never tried to edit the videos into anything together however you can see the poses in many of the photos.

The ride itself has a good variety of terrain, great views in places, confusing areas where it is difficult to follow the track and we all had fun. Photos and some words are online on my Hume and Hovell track ride 2012 page.

Binh Nguyen: Middle Eastern/African/Asian Background, NSA Whistleblowers, and More

Wed, 2015-11-18 02:22
- whenever you take a on a new job you feel naive (the following are all publicly available videos/documentaries often from well known media outlets). Despite what is being said by a lot of people in the public spotlight I don't believe that there is a way to acheive victory in a timely fashion. Kids of primary school age are being trained to hate the West, to learn how to use weapons, to become

Gary Pendergast: Replacing Rdio

Tue, 2015-11-17 23:26

I guess we’ve all heard of the impending demise of Rdio.

As one of the 500k subscribers with good taste in their streaming apps, it’s now time to consider a replacement. Here are my criteria – some of them may vary for you, but it’ll hopefully give you an idea for how you can choose, too.

Must Have
  • Offline sync to mobile (I listen to music when I’m flying a lot)
  • Ability to play from my Mac (I listen when I’m working)
  • Ability to play on Sonos (the rest of my house)
  • Family accounts
Should Have
  • Desktop App (I kill my browser pretty regularly, I don’t want that to interfere with my music)
Nice To Have
  • Android Auto support (I don’t have an Android Auto device, but I’m likely to buy one in the near future)
  • Account sharing instead of family accounts (it’s cheaper, and my wife and I mostly don’t use the account in different locations at the same time)

Given that the death of Rdio was most likely due to its lack of market share, I decided to only go with major players – this quickly narrowed it down to Google Play Music, Apple Music, and Spotify.

Google Play Music

Out of the box, Google Play Music does okay – it has an excellent selection of music, the mobile app isn’t terrible, and it works on Sonos. YouTube Red is supposed to be pretty nice, too, but it’s currently not available in Australia.

It falls down heavily when using it on my desktop, though. There’s a Chrome extension to hook into my keyboard media buttons, or there are third party apps available, none of which are very good.

Finally, it becomes completely unusable to share with my wife – I obviously can’t sign into my Google account on her phone, and Google still don’t have family accounts (though they have been announce as “coming soon”).

Apple Music

I’ve never had a good relationship with iTunes – it’s always been a clunky beast, and my recent experiments seem to indicate that not much has changed, except for a re-skin of some of the UI. It feels really hacked together. It is a native app, though, so it wins points by not being associated with my browser.

The family account was super janky to setup, I found the UI kept dying on me. Eventually I got through, however, and I hopefully will never need to touch that again (famous last words…).

On the bright side, the Apple Music app for Android is really nice, despite being a recent beta release. There’s no word on if it supports Android Auto, but that’s not an immediate requirement for me, so I’m happy to let it go.

Spotify

Spotify’s biggest benefit is that it’s not attached to a personal account. Unlike with Google or Apple, my wife and I could share the same account, without needing to share our personal logins. It’s cheating the system slightly, but it’d save us $6/month, so I’m not too concerned about it.

Spotify’s apps have been severely ugly in the past, but the good news is that the Android app is much more useable now. Unfortunately, I was unable to try out the OSX app, because the downloader was broken. The web app requires Adobe Flash, which is a total non-starter.

Conclusion

In the end, I chose Apple Music, for two reasons. One, it was the only one with a desktop app that actually worked. And two, it’s the only service that I can play Taylor Swift’s 1989 on. If the other services can’t get their act together enough to negotiate for a popular album to be on their service, then I’m concerned about their future ability to do so.

I may end up needing to re-evaluate this decision, particularly if the Sonos support doesn’t happen before Rdio finally closes it’s doors (I’m maintaining my Rdio account just for that). But for now, this will do.

Sridhar Dhanapalan: Twitter posts: 2015-11-09 to 2015-11-15

Mon, 2015-11-16 22:27

Steven Hanley: [mtb/events] Australian Single Speed Nationals 2012 - Beechworth, Bushranger themed (sort of)

Mon, 2015-11-16 22:25


Posing with Jeebus (fullsize)

Wow right now I am finding it surprising I have not been to the single speed nationals since 2012, (un) organised every year by a group of locals somewhere, sort of overseen by Australian Recreational Singlespeed Enthusiasts (ARSE). The 2010 Canberra SSNATS event in Majura Pines was heaps of fun, organised by Canberra One Gear Society (COGS).

In 2013 the event was in Cairns and though it sounded fun I decided it was just a bit too far to head up there for the event, in 2014 I tried and tried to talk friends into heading up for the weekend in Dungog NSW, however few of my Canberra friends were keen and I did something else that weekend (softie that I am).

I am still hoping the road trip to Wombat State Forest in Victoria will go ahead for the 2015 event. There was a ANZAC event in Rotortua over easter however I skipped that. This however is all getting off the topic of 2012.

I made it down to 2012, camping with McCook and having a fantastic weekend of mtb riding with the crew in Beechworth. The rather important aspect of beer was sorted that weekend and Bridge Road Brewerers in that town and they are possibly my favourite brewer in Australia.

The Beechworth mtb park is a great mix of interesting technical stuff and fun all in native bush, there were other ride options as can be seen in my gallery also. Photos and words from the 2012 Australian Single Speed Nationals are online in the link.