How does the Garmin eTrex H navigate routes?

I hate not knowing how something works. My childhood is littered with electronic devices pulled apart and analysed … radios, motors, cameras, computers.

I couldn’t figure out how the eTrex navigates along a route so I had to run some field tests which for a GPS unit means going for a walk. The first few tests were inconclusive so on the way to work this morning I walked along a 3-point route and checked how the Garmin calculated the next waypoint at four points along the route: before the route, between the first two waypoints, between the second two and after the route. I checked it both ways, so following the route to the northmost waypoint and then to the southmost, so eight datapoints all up.

The results are depicted in the diagram below; the results for following the route south are the same as the reverse of following the route north so I’m just showing the four scenarios here:

The eTrex assumes that you are standing at the first waypoint so it doesn’t bother to navigate you to the first waypoint. Whilst you can create a two-waypoint route it doesn’t really make sense as it will navigate directly to the second and final waypoint so you might as well just GOTO that waypoint – except that if you have the two waypoints as a route you can see a line between them on screen which might help you orient.

The Garmin eTrex chooses which waypoint to send you to depending on where you are in relation to the waypoints. If you’re closer to a waypoint further along the route it’ll just skip earlier waypoints and won’t make you U-turn.

In this following additional test I walked past the second waypoint instead of going to it. Once the eTrex determined I was giving the second waypoint a miss bypassing it by 70 meters it switched over to the third and final waypoint:

How should I do this formatting?

GPS Visualizer has this great tool for converting a GPS file to GPX but I have an unorthodox need for it: to convert a comma-separated list of coordinates from a LineString element out of Google Earth.

Google Earth copies elements as KML so you can copy an element such as a path from Google Earth and paste it into a text editor. Locating the LineString element in the XML is relatively easy but it would be nice if there was an easy way to convert the single string into the proper CSV format needed to run it through the converter (shame Google Earth doesn’t write GPX natively).

This is what a LineString looks like (no line breaks):

172.2384849468256,-41.46954787285365,0 172.2432306652765,-41.46826502144933,0 172.2482385664333,-41.47388161005981,0

This is what I need to plug into the conversion tool (with line breaks):

name,desc,longitude,latitude
WP01,Waypoint,172.2384849468256,-41.46954787285365
WP02,Waypoint,172.2432306652765,-41.46826502144933
WP03,Waypoint,172.2482385664333,-41.47388161005981

I currently do this manually by:

1. Copy LineString string of coordinates out of pasted KML and into a new text editor instance
2. Search and replace ,0  with \n
3. Copy and paste into Google Docs spreadsheet (which has default waypoint names and column headers)
4. Copy whole spreadsheet back into text editor
5. Search and replace \t with null

It’s a bit time consuming and putting me off from plotting routes in Google Earth, and is prone to error so some macro or something that can do this simple step automatically would be great.

Ideas?

Triple J Hottest 100 2010

My shortlist, with the 10 tracks I voted for in bold:

• Art Vs. Science – Magic Fountain
• Ash Grunwald – Lady Luck
• Avenged Sevenfold – Nightmare
• Bamboos, The – Turn It Up {Ft. Lyrics Born}
• Beautiful Girls – Don’t Wait
• Boy & Bear – Fall At Your Feet
• Cee Lo Green – Fuck You!
• Crystal Castles – Not In Love {Ft. Robert Smith}
• Cypress Hill – Rise Up {Ft. Tom Morello}
• Delphic – Doubt
• Digitalism – Blitz
• Florence & The Machine/Dizzee Rascal – You’ve Got The Dirtee Love {Live}
• Flight Facilities – Crave You {Ft. Giselle}
• Gorillaz – Stylo {Ft. Bobby Womack and Mos Def}
• Gotye – Eyes Wide Open
• Mark Ronson & The Business Intl – Somebody To Love Me {Ft. Boy George & Andrew Wyatt}
• M-Phazes – Goodbye Gravity {Ft. Muph & Plutonic/Candice Monique}
• Naked And Famous, The – Punching In A Dream
• OK Go – This Too Shall Pass
• Pendulum – Witchcraft
• Raekwon – Kiss The Ring {Ft. Masta Killah & Inspectah Deck}
• Sia – Clap Your Hands
• Stonefield – Through The Clover
• Subs, The – Kiss My Trance
• Subs, The – Mitsubitchi
• Washington – I Believe You Liar
• Yolanda Be Cool/DCUP – We No Speak Americano

2010, a year of healing

As I suspected in my wrap-up blog post for 2009 this year was about a deeper recovery from my upbringing in a toxic cult. I didn’t know or accept it at the time but having now been through several months of psychological counselling and on a prescription for anti-depressants I now realise that my sense of that ‘something beneath the surface’ was depression. So the first half of 2010 was all about therapy and recovery: exploring my past and dissolving the mental and emotional scar tissue to become a more functional, whole and contented person.

The change after therapy and starting medication was so drastic that Jenny now refer to the history of our relationship as two eras: Before Medication and After Medication, although of course the drugs were only part of the solution. We don’t like to talk about the dark days of Before Medication.

So while 2010 has been pretty awesome in that regard the first half was a bit rocky. My psychologist had me in tears every session and I’d need to take time to pull myself together before going to work. It was hard work but bloody worth it. One of the more tangible outcomes of the therapy is that I now have a much better relationship with my dad; I no longer bear a grudge for his part in my being brought up in a cult and how much work he created for me in leaving and recovering from that place. Just evidence of how I’ve come to terms with my past and integrated the first 25 years of my life into who I am now rather than shunning that part of my life as something I’d rather forget. Like alcohol on a raw wound, it was a painful process but I’ve come out of it healthier and stronger.

I still want to write a book about my experiences growing up in a fundamentalist Christian cult but I’ve put that on the back-burner till I get to New Zealand. I think I’ll have a lot more spare time, less distractions, easier to focus on a big project like that. The change of scenery should help inspire me too.

Oh yes, in case you didn’t know we’re moving to New Zealand next year! In fact I’ll be flying over on the 8th of January and starting my new job on the 10th – you can read more about that on my new NZ blog.

Looking forward, 2011 is going to be pretty awesome but won’t be without its challenges – moving overseas, living in a new country, leaving behind most of our stuff and creature comforts, making new friends, adjusting to a new culture, starting a new job, transitioning from government work to private sector … but they’re all challenges I fully embrace and look forward to. I think 2011 will be amazing and this graph of personal growth and life experiences that started in mid-2008 for me is showing no signs of slowing! Maybe 2012 will be a bit quieter, though not if I have anything to say about it!

Back on Facebook, sort of

I still stand by my reasons for leaving Facebook but with me leaving for New Zealand soon I need a way to keep in touch with my friends who aren’t on Twitter. So I’ve joined Facebook again but will only have a barebones profile and my only posts will be tweets syndicated through the Selective Tweets app that have been tagged with #fb.

facebook.com/nathanael.boehm

I will not be actively using Facebook, I will not be logging in and people can’t post comments on my wall. But at least I have some sort of presence there now so you can follow me and feel free to drop me a note at nboehm@purecaffeine.com or on Skype nathanael.boehm to chat.

About CTUB

I sent out a general information email to the CTUB mailing list this morning – thought it might be of interest to non-subscribers too:

There are now ninety people who subscribe to the CTUB mailing list and I thought it was about time I just sent out a general information email about the Canberra Twitter user group and meetups.

The CTUB group was formed towards the end of 2007 as part of a national initiative to create communities of Twitter users in capital cities – for example there’s STUB in Sydney, MTUB in Melbourne, PTUB in Perth and so on.

The main purpose of CTUB is to hold events where people who mainly converse online via any sort of microblogging platform such as Twitter, Plurk, Foursquare etc can come together to meet in real life in a friendly community environment at a local cafe or pub for a drink and a chat.

We have held around 40 CTUB events since our first one in 2007 with guest appearances from interstate tweeps from Melbourne, Sydney, Brisbane, Cairns, Adelaide and Perth.

It would be great to see more of you at our events so if you have any feedback on how we can encourage you to come then please let me know.

Please note this is an open mailing list in that any of you can email ctub@mailmanlist.net to message the whole group so feel free to organise a CTUB yourself – I’m not the sole coordinator, I just happen to run most of the events. Just make sure you keep mailing list traffic low.

We also sometimes use Eventbrite to collect RSVPs for CTUB events. Sometimes like the last one it’s just an open call for anyone who wants to turn up because we rarely get more than ten people to an event.

Thank you all for your interest in CTUB and those of you who have attended and supported previous CTUB events.

If you have any questions please let me know.

If you live in or near Canberra and want to be a part of CTUB then follow us on Twitter and join the mailing list.

Looking for a band

My band The Camals has pretty much disbanded, at least for the next 6 months so I’m looking around for another local band to join. I play keyboard/piano/synths, drums/percussion and bass guitar.

BarCampCanberra 2010

Our next BarCamp is scheduled for 6 February 2010. Register now!

New blog: Lounge Sessions

After trashing my purecaffeine.com blog mid last year and replacing it with a blog focussed on user experience design, social media and Government 2.0 I lost a place to post random thoughts about the web industry in general, work, the various projects I’m involved with, photography, cooking, philosophy, religion … so I created a Tumblr blog.

I hardly used it – it didn’t support comments natively and plugging in Disqus kinda sucked, so I ended up neglecting it.

I was sitting here tonight thinking about thinking and I couldn’t get my head around any topic in particular – some people suggested just writing stuff; but I don’t have a place for that. Except my other secret blog, which I’ve also since neglected.

So I’ve created yet another space to share other ideas and thoughts that don’t fit in my other blogs, to replace my Tumblr blog.

My jQuery Persist Helper Text plugin

I wrote a jQuery plugin last night. Pretty simple, but yeah, my first published plugin.