Netflix Socks - automatically pause your binge-watching if you fall asleep!

So the Paris Climate Conference went well, and we have apparently solved the problem of global warming - what's the next major problem humanity should tackle?

Well, it's obvious really:

You're binge-watching your favourite TV series on Netflix, you fall asleep, and you wake up two hours later having missed a couple of key episodes.

The good people at Netflix have a simple solution that you can make for yourself:

Netflix Socks http://makeit.netflix.com/netflix-socks

These amazing socks detect when you have dozed off, and send a pause signal to your TV / set-top box. A bright LED flashes a warning, so that you can press the over-ride button if you are awake and just happen to be sitting very still.

You can install the Netflix Socks adapter into your favourite pair of comfortable TV-watching socks, or you can download the knitting patterns to theme with your favourite Netflix shows, including Bloodline, Unbreakable Kimmy Schmidt, BoJack Horseman or House of Cards.

http://makeit.netflix.com/patterns/templates.zip

The parts list http://makeit.netflix.com/netflix_socks_materials_list.pdf is pretty simple:

• A pair of TV-watching socks (raid your sock drawer, or knit a pair of Bloodline socks)
• Arduino microcontroller (get one of the tiny "wearable" models, such as the Arduino Pro Trinket https://learn.adafruit.com/introducing-pro-trinket/setting-up-arduino-ide or AdaFruit Gemma https://www.adafruit.com/products/1222)
• IR LEDs (to control the TV)
• LED indicator light (to alert you that the Pause function is about to trigger)
• Battery
• Momentary button (the over-ride switch)
• Accelerometer
• 12” x 12” piece of felt

You should be able to make yourself the adapter for a few dollars, or you may even already have most of the parts if you have tinkered with Arduino before.

Enjoy!

Survey results: "Color Vision and the Efficacy of EnChroma Glasses"

Blake Porter has published the results of his on-line survey http://www.blakeporterneuro.com/color-vision-efficacy-enchroma-glasses/ into the efficacy of EnChroma sunglasses as an aid for compensating for colour blindness. He previously published a fantastic piece entitled "What is color? Enchroma glasses, neuroscience, and the mystery of color" http://www.blakeporterneuro.com/enchroma-neuroscience-color/, which I mentioned in an earlier post http://julianh72.blogspot.com.au/2015/09/fantastic-article-on-enchroma-glasses.html - do take a look at this article, if you have not already done so - it is a fascinating read and very thought-provoking.

A total of 406 people responded to the survey, so it is a useful sample size. A significant majority of respondents were males in their twenties, which is not really surprising - males are more commonly affected by colour blindness than females, and the poll was conducted as an on-line survey, so some internet-savvy was required to even be aware of the poll, and then to complete it.

And the results of the survey?

In a nutshell - they really do work, for the majority of users.

http://i1.wp.com/www.blakeporterneuro.com/wp-content/uploads/2015/11/EnChroma-effective-time.png


You really need to read the whole article to get the full picture, but the Conclusion sums it up pretty well:

Conclusion

What we may conclude with some certainty is that people who have a language full of color words, are color blind, and then use corrective means to aid their color blindness, new conscious color perceptions are near instantaneous, possibly due to the broad processing capacity of the visual system, and there seems to be an intuition present, possibly due to knowledge from language, allowing these people to correctly assign their new colors with language. Overtime, their processing of new colors and their ability to discriminate across colors will be improved and the time course of this may be age dependent.

The work by Blake Porter is licensed under a Creative Commons Attribution-Non Commercial-ShareAlike 4.0 International License

Ultrascope - Open-Source Automated Robotic Observatory

Here's one for the Geeks and Makers:

Ultrascope - an open-source Automated Robotic Observatory:
http://www.openspaceagency.com/ultrascope/
https://www.onshape.com/cad-blog/who-wants-to-go-hunting-for-asteroids

The Ultrascope project (currently in pre-Beta) aims to develop a kit-set robot telescope (or ARO - Automated Robotic Observatory), that will allow amateur astronomers to contribute to citizen science projects for a radically reduced cost - e.g. asteroid hunting, etc.

The first project is the Explorer Series Ultrascope, which is a 90 mm (3.5 inch) reflector ARO that is able to conduct celestial photography and photometry. The kit will be released as open-source plans for 3D printing or laser cutting, paired with an Arduino controller and a high-pixel smartphone (eg Lumia 1020 with 41 Megapixel CCD).

They are also working on a 200 mm (8") version, the Odyssey.

Things I wish somebody had told me when I started building a RepRap 3D Printer

Or to be more accurate:

Things people told me which I wish I had listened to more attentively when I started building a RepRap 3D Printer

My RepRap is a 1st-generation Prusa Mendel http://reprap.org/wiki/Prusa_Mendel_(iteration_1) which was pretty much the bee's knees in affordable DIY 3D printing back in August 2011 http://julianh72.blogspot.com.au/2011/08/first-post-inspirations.html.

I bought a kit of plastic bits and "vitamins " (nuts and bolts etc) on eBay, and self-sourced all of the other components (stepper motors, electronics, etc). The buy-and-build process was itself instructional (and fun!), and about two months after construction commenced, I had a workable 3D printer in operation. http://julianh72.blogspot.com.au/2011/10/cheers.html

The Prusa Mendel and its predecessors truly embodied one of the core philosophies of the RepRap Project: RepRap is short for Replicating Rapid-Prototyper; that is, the 3D printer can (almost) build itself. To this end, the maximum possible number of components were made from 3D-printed plastics, right down to the z-axis couplers and axis bushes.

These days, if you start a similar adventure, you are more likely to try building a 3rd-generation Prusa i3 http://reprap.org/wiki/Prusa or similar. To the uninitiated, it is hard to see how the Prusa i3 is directly related by just two generations from the Prusa Mendel, but for those of us "in the know", the family heritage is obvious.

1st-Generation Prusa Mendel (Ref: http://reprap.org/wiki/File:Assembled-prusa-mendel.jpg )

Current-generation (October 2015) Prusa i3 (Ref: http://reprap.org/wiki/File:Prusai3-metalframe.jpg )

The Prusa i3 (and other current-generation 3D printers) embody the accumulated learnings of both the originators of the RepRap Project, and thousands of RepRappers. The kits are cheaper than ever, but use a variety of materials and forms of construction, with less of an emphasis on using 3D printed materials for all components, for reduced cost and increased reliability / performance. (Steel or aluminium are just better at some jobs than plastic!)

Some may argue that this somehow "dilutes" the essence of RepRap, but for me, it makes the goal of ownership of an affordable and reliable 3D printer far more attainable, while still allowing freedom for experimentation and development/. (One of the great advantages of going down the open-source path, rather than buying a proprietary model, is that you can modify and upgrade your machine as often as you like, sharing your experience with that of many other like-minded individuals, so your humble beginnings can evolve into something better and better.)

In no particular order, here are my main learnings over the past few years:

1. You NEED proper mechanical linear bearings on all axes - 3D-printed PLA bushings are a nice philosophical concept, but realistically, the motion will be MUCH smoother and jitter-free if you install linear bearings (LM8UU or similar). Do yourself a favour, and buy a kit which uses them (most modern kits do), of else, print yourself some replacement carriage parts which are designed for LM8UU bearings instead of PLA bushings, and install them as soon as possible. http://julianh72.blogspot.com.au/2011/11/smooth-operator.html
2. You NEED a heated print-bed. Yes, it is possible to print on painter's tape etc, but life is MUCH easier when you have a heated print-bed. http://julianh72.blogspot.com.au/2011/12/hotbed-of-intrigue.html And this leads us to ...
3. You need a power supply with heaps of capacity. I started off with a hacked ATX power-supply http://julianh72.blogspot.com.au/2011/08/my-parts-list-power-supply.html which I thought had enough capacity (16 amps @ 12 volts), and while it did work, it turned out that it had trouble maintaining full supply voltage under heavy load. I have replaced it with a more robust true 15-amp sustained (18-amp peak) power supply http://julianh72.blogspot.com.au/2015/10/powertech-mp-3800-0-24-volt-power.html , and it runs much better now.
4. Get rid of the 3D-printed Z-axis couplers, and replace them with engineered metal shaft couplers. You can pick up 5 mm x 8 mm aluminium couplers for a couple of dollars on eBay, and I have found that they grip the smooth stepper motor shafts much better than a plastic clamp - of which, I printed and installed quite a few design variants http://julianh72.blogspot.com.au/2011/11/smooth-operator.html. (This is particularly important for a machine like the 1st-gen Prusa Mendel where the X-Axis is suspended from the Z-Axis motors; possibly less of an issue on the Prusa i3, where the motors are at the bottom, so the couplers are in compression, not tension.) They also run MUCH smoother, as they are able to take up the angular and offset errors between the motor and the threaded rod with a more reliable spring stiffness than the plastic clamp couplers.
5. Get yourself an LCD Controller, like the RepRapDiscount Smart Controller http://reprap.org/wiki/RepRapDiscount_Smart_Controller - this will allow you to print without a computer attached, freeing up desk-space, and also removing one link from the failure chain. These can be bought very cheaply on eBay - highly recommended.
6. If you are running an old-generation plastic-bodied print-head (PTFE and / or PEEK), replace it with an all-metal print-head with a heat-sink and fan. These run MUCH more reliably than the old PTFE-bodied print heads, and are also much more physically robust, and are able to withstand the occasional (and inevitable) print-head crash.

My 1st-generation Prusa Mendel has had all of the above upgrades applied to it - it is still physically the same arrangement as it stared life, but it now prints much more reliably and smoothly (and faster) than it did before. Dare I think that the "tinker and upgrade" phase has ended, and my RepRap will now enter a long mature life of production printing without significant additional upgrades?

(Naaah! Who am I kidding?! Of course I'll keep upgrading it - just watch this space!)

(As in all matters of opinion, some of these points may be controversial - for example, I am sure that some people have printed very successfully with 3D-printed PLA bushings, and continue to do so, but in my opinion, you are more likely to print successfully, and much more quickly, if you use linear bearings on all axes.)

PowerTech MP-3800 0-24 volt power supply - a quick review

I have been powering my RepRap 3D printer with a hacked ATX power supply http://julianh72.blogspot.com.au/2011/08/my-parts-list-power-supply.html - it has been working OK, but I was finding that it could be a bit slow getting the heat bed up to a stable temperature, especially if I want to print ABS (which needs a very hot heat-bed to stick properly). When I hooked up my multimeter, I found the supply voltage was dropping a bit under heavy load, so I guess my power supply really wasn't 100% up to its rated capacity. I started thinking about getting a proper desktop variable voltage power supply.

Luckily for me, JayCar recently had a special on several power supplies, including the MP-3800 http://www.jaycar.com.au/Power-Products-Electrical/Power-Supply/Laboratory-Bench/Compact-Switchmode-Laboratory-Power-Supply/p/MP3800, which they were offering for only AUD$119 (usually $149) - not bad for a 0-24 volt power supply, with a load rating of 15 amps continuous at 12 volts (18 amps peak). It is rated to better than 9 mV ripple voltage, and has thermal and overload protection, so it ticks all of my boxes.

Note that the rated output current capacity depends on the selected output voltage, so check your needs if you plan to run at other voltages:

So I grabbed one, hooked it up to my RepRap, and it works great - highly recommended!

The power supply has back-lit analogue gauges for volts and amps, which seem to be pretty accurate when I test against my multi-meter. The RepRap pulls a maximum load of about 12 amps during the heat-up phase, but this drops to around 5 - 6 amps during normal printing. The power supply handles this admirably, with no detectable fluctuation in supply voltage, even when the load is fluctuating rapidly, such as when the heat-bed is cycling on and off.

The voltage control knob has a central detent position, at which it delivers 13.2 volts, which is where I normally run the RepRap. (The RAMPS 1.4 card is nominally a 12 volt board, but it can happily take a little bit of over-voltage, and the extra supply voltage gives faster and more stable heat control.) However, I need to be sure to not accidentally overload the RAMPS by giving it 24 volts - I really wanted a digital display to give a crystal-clear voltage display, to make sure I don't over-power my RAMPS 1.4.

I bought a cheap 0-30 volt LED voltmeter on eBay for less than $3 including postage (search for "0.36" LED Digital Voltmeter", and make sure to pick one which has the right voltage range for your power supply, as they come in 10V, 30V, 100V and 200V variants). Hook up the red and blue wires to the positive terminal and the black wire to the ground terminal, and you have a nice bright digital voltage display.

I then printed a voltmeter bracket which I came across on Thingiverse http://www.thingiverse.com/thing:239801, and it works great - now I get a brilliant indication of supply voltage as soon as I power up, greatly reducing the risk of blowing the RAMPS electronics. (And of course it works just as well when I am using the power supply for my other electronics projects.)

Fantastic article on "Enchroma glasses, neuroscience, and the mystery of color"

I just came across this article entitled "What is color? Enchroma glasses, neuroscience, and the mystery of color" by Blake Porter:
http://www.blakeporterneuro.com/enchroma-neuroscience-color/

It's a pretty lengthy piece, but well worth taking the time if you have an interest in how the human brain perceives colour, what colour blindness is, and how the EnChroma glasses work. You might also want to participate in his survey after you've read through the article:
https://docs.google.com/forms/d/1VB4L7EQSkZ4M_IRrzjehXlMjToKTZcGQd3xKy3321cw/viewform

Porter's article explains the processes far more eloquently than I can. I've always been OK with Fire Engine Red, Canary Yellow, Sky Blue, and so on, but all of the intermediate and pastel colours have always been a problem, tending to blend into an undistinguished green-red-brown-pink-purple. Many colours that are dramatically different to most people are virtually indistinguishable for me.

The best description that I have been able to explain the EnChroma experience is like sitting in front of a well-adjusted colour TV, and then turning the “Colour / Saturation” settings up by about 25% – all the colours are “real”, but they become much more rich, vivid and saturated. Pastel shades which have very little colour intensity to my unaided eye now show much more saturation, with what were previously subtle differences between two shades now becoming much more distinguishable.

Green traffic lights are a good case in point – they've always looked white with a green tinge to my eye (like a fluorescent tube), but now they are definitely green. The other big “wow” factor for me is the sunset sky – I've always been vaguely aware of various shades of red, orange and pink at sunset, but they are generally very subtle and it’s only rarely bowled me over, but with the EnChroma lenses, every sunset is a delight! (I don’t know if this is what I've been missing my whole life, or of I'm seeing something that people with normal vision don’t see, but whatever it is, I really like it!)

But beyond the main EnChroma / Colour Blindness theme, there's some fascinating stuff about the impact of language and culture on our perception of colour. Did you know that the ancient Greeks didn't think the sky was blue? Or that there is a tribe in modern-day Namibia who can easily see the one square in the first pattern below which has a different shade of green (I sure can't), but struggle to see the blue square in the second pattern? Amazing stuff!

More musings on EnChroma sunglasses for colour blindness

It was a pretty big decision for me to go with the EnChroma sunglasses without having the opportunity of trying them first, but there are no dealers in Australia at present. However, I did a fair bit of research first, and took some comfort from the 30-day money-back guarantee (which I won't be using!)

I don't want to disparage other glasses which are advertised as enhancing colour blindness, as they may work well for many people, but I tried another brand a few years ago, and they didn't have a huge effect for me. (The EnChroma lenses are chalk and cheese in comparison for me). With respect to the technology aspect (narrow-band "notch" filters vs. "broadband" dye filters) - I don't know whether the benefits of narrow-band filters will apply equally to everyone, and I don't know whether any of the other brands are now using narrow-band filters - their website aren't always clear on the exact filter technology being used.

Narrow-band filters (as used in EnChroma) cut out a very specific "notch" of wavelengths (colours) while allowing very similar adjacent wavelengths to pass almost unaffected. Broadband dye filters (which is what the brand I tried previously  USED to use, but I am not sure about now) generally suppress a range of colours, but then a have smooth "shoulder" of rising transparency for the adjacent colours that you want to pass - think of it as a sheer-edged canyon versus a smooth river valley.

If I make a rainbow spectrum with a glass prism and look at it with the EnChroma lenses, there are two distinct dark lines in it, one in the Blue end, and one in the Red-Green end. See this shot which I took (yes, I'm a science geek!) which shows the effect:

I expect to see the same effect on natural rainbows (but I haven't seen any since I got the glasses) - they will presumably split into three coloured bands with a narrow gap between them.

I think this is why the EnChroma lenses work so well for me - the Red-Green "notch" drives a "wedge" between my Red and Green receptors, allowing my eye to see colours in the Red-Green range as either predominantly Red or predominantly Green, but it does have the side-effect of making a few colours that span right across the "notch" a richer, darker colour (drab olive greens and khaki colours tend to become richer in hue but darker).

The broadband dye  filters that I tried a couple of years ago don't have such a strong differentiating effect for me, but others may get a different effect (and they may have changed their lens technology in the last couple of years).

I think that the Blue notch in the narrowband  EnChroma filter is not particularly "useful" for enhancing my colour perception (as I am Red-Green colour blind), but it is also why some digital displays get a green cast - if the peak wavelength of the Blue pixel in the RGB display falls right in the "notch", then the Blue signal is heavily suppressed, and White on an RGB display with very little Blue signal tends to come out greenish. So far, it seems that some (but not all) outdoor digital signs have this effect, and OLED computer / phone / tablet displays in particular seem to have the effect, but LED computer screens and TVs seem to be fine. My guess is that the Blue pixel in those outdoor signs and OLED displays happens to fall right in the "notch", but other display types have a different spread of Blue in their RGB mix, so plenty of Blue still gets past on each side of the "notch".

I suspect that the exact narrow-band filter "notches" that EnChroma use on their Cx-65 Indoor / Computer lenses may be tuned differently, to avoid excessive tinting on digital displays (but I haven't tried a pair to be certain).

I haven't noticed any "weirdness" from the Blue notch in general viewing of "natural" objects - the sky is still sky blue, but maybe some very specifically coloured blue flowers might darken significantly? (I'm looking forward to Jacaranda season as a good test - Jacaranda trees in flower are an intense vivid colour to my unaided eye; I'll be interested to see if they change with the EnChroma lenses.)

So ... what does it actually LOOK like when you wear a pair of EnChroma sunglasses?

That's a tricky question to answer, because when you think about it, you don't know what the world actually looks like through my eye's (or anyone else's), and I don't know how you perceive all the colours around you. The world looks "normal" to me, even though I perceive it differently to you.

I've been wearing the EnChroma sunglasses http://enchroma.com/ for a couple of days now, and the best overall description I can provide is to imagine turning the colour down on your TV or computer screen until it's black and white, and then bring it back up to 6/10 or 7/10 - that's sort of what the world looks to my unaided eye - the colours are all there, but they're all a bit muted and subdued.

(Actually, that's NOT how the world looks to me, but it's the best simulation I can think of!)

Now turn the colour back up to "normal" viewing (10/10), and then take it up to 11:

THAT'S roughly what the world looks like to me through EnChroma - everything becomes more saturated, and just "pops".

The effect is most noticeable on pastels and other unsaturated colours - they all become richer, denser and more saturated. If a particular shade has just a touch of red, or green or yellow, it will seemingly "boost" the colour to make it several shades "richer". You know how an external painted masonry wall will fade over time, and all your favourite shirts fade with multiple washes? It's like giving the wall a fresh coat of paint, or buying a new Hawaiian shirt.

Bright, saturated primary colours aren't affected nearly as much - but I can see most of them clearly anyway. Fire engines and mail boxes are still "signal red", the sky is still sky blue, Hi-Vis Safety Shirts are still canary yellow. But when you think about it, most of the colours in the world around us are a bit more subtle and muted than that, and it's these unsaturated colours which seem to get the strongest boost.

There were a few surprises as well:

Green traffic lights have always looked almost white to my eye, with only the slightest hint of colour - a bit like how "warm white" compact fluorescent bulbs look compared to the "cool white" ones - but now they are bright green. Also, for the first time ever, red traffic lights are brighter than amber traffic lights, whereas the amber has always been quite a bit brighter than the red to my eye.

The EnChroma lenses can give a strong green cast to some (but not all) digital displays – my SmartWatch and tablet are now green when they should be white (both have OLED screens), and there's an LED display board near my work which is now green, but my TV and phone look pretty normal (but a bit dark!), and as I sit at my computer typing this reply, the white is just white.

Interestingly, the blue LED status lights that you often see on electrical equipment seems to be a colour that my unaided eye sees very brightly, but the EnChroma lenses seem to block very strongly. I noticed it first on our TV Set-Top Box and a computer monitor at home, and also on the lift buttons at work. Even though the lift is well illuminated and I can see fine with the glasses on, the floor button back-lights almost disappear completely when I put the glasses on. I guess it depends on the exact colour spectrum of the RGB pixels - it would be interesting to see if this effect persists with the Cx-65 lenses, which are apparently optimised for digital screens and the like.

Drab greens and browns (I'm thinking of colours that you would probably describe as faded olive green or mission brown) become a LOT more dense, and therefore get quite a bit darker - again, it's a bit like over-painting a faded fence with new paint which is a couple of shades darker. I think these colours must lie pretty well in the red-green "notch" in the EnChroma transmission spectrum.

I suspect things like army camouflage would be pretty strongly affected by this - but I haven't seen any army vehicles or personnel since I got the EnChromas. (Or maybe I did, but they disappeared totally against a dark background?)

Anyway, that's enough of a report for now - I've got to get back outside to look at some more flower beds. (And look for that Jeep that I misplaced somewhere.)

Spectroscopy of EnChroma Cx 15 lenses

I have taken a few spectroscopy images of the white light of a halogen bulb as viewed directly, and through a pair of normal (polarised) brown-tinted sunglasses,  and through the EnChroma Cx 15 lenses.

Here's the direct halogen spectrum,  unfiltered:

(Ignore the streak on the left-hand side -  the interesting bit is the rainbow on the right.) 

This is the spectrum as seen through the normal sunglasses - you can see that they suppress all wavelengths more or less uniformly:

And here's the view through the EnChroma lenses - you can see that they have two very distinct bands where virtually all light is blocked out,  while other wavelengths pass with very little attenuation :

I've also shot a short video showing the effect -  you should have no trouble working out when the normal sunglasses and the EnChroma lenses come between the light and the spectroscope:

"Color for the Color Blind" - A quick review of EnChroma Sunglasses

I'm severely Red-Green Colour Blind (technically, I have Deuteranomaly https://en.wikipedia.org/wiki/Color_blindness#Types, a genetically transmitted condistion). 

I’ve just acquired a pair of EnChroma Cx Explorer sunglasses, which are designed to boost colour perception for many people who suffer from colour blindness. (See http://enchroma.com/ ) 

The theory is that for people with normal vision, the Red receptors in the eye respond strongly to red, but only moderately to red-green colours, while the Green receptors respond strongly to green, but only moderately to red-green colours. For people with Red-Green colour blindness (which is my problem), the red and green receptors in the eye overlap in their colour reception, and both respond strongly to similar wavelengths in the red-green range, so they don't differentiate between red and green as well as a normal eye.

The EnChroma lenses effectively transmit red and green, but largely block the intermediate red-green colours, so the red receptors will be triggered strongly by red but not by red-green (which are blocked by the lenses), while the green receptors will be triggered by green but not red-green. 

Where these glasses differ from other products that I have seen advertised before is that these use narrow band-pass "notch" filters to cut out a very tightly defined band of red-green, whereas the more common type use pigmented dye filters, which filter out a wider and less clearly defined band of colours. 

http://enchroma.com/technology/

(The EnChroma lenses also have a "notch" for blue-green, which could be beneficial for some forms of colour-blindness, but is probably not so important for me - although maybe it helps with the overall effect as well?) 

My pair arrived yesterday.

So - do they work? In a word:

YES!

They're quite dark (just 14% overall light transmission), so they're intended for full daylight use, not really suited for indoor use. If you're wondering - 14% transmission is pretty typical for a sunglass lens designed for full sunlight. E.g. Oakley provide a range of tints from 9% to 11% for "Extremely bright light", while 13% to 22% are rated for "Medium to bright light".

http://www.evo.com/oakley-sunglasses-lens-tint-guide.aspx

EnChroma offers three lens shades: 14% for "strong daylight", 25% for "medium-to-low light outdoor conditions" and brightly-lit indoor use, and 65% for general indoor / computer use. The 14% has the strongest colour-correcting effect, which is why I chose it.

http://enchroma.com/cx-lens-guide/

In muted light this morning (7:30 am, a bit of light cloud / mist), the effect outdoors was obvious - a lot more contrast and definition between various shades of green and red in the garden.

But as the sun broke through - WOW!

Colours became quite eye-popping - our dry winter lawn became a vivid green, pastel flowers that always faded into the background suddenly stood out ...

The most dramatic difference was driving in to work - so, green traffic lights are actually green? Who knew?! J

(Green traffic lights have always looked almost white to my eye, with only the slightest hint of colour, but now they are bright green. Also, for the first time ever, red traffic lights are brighter than amber traffic lights, whereas the amber has always been quite a bit brighter than the red to my eye.)

Some unexpected effects - they can give a strong green cast to some (but not all) digital displays - my Android tablet is now green when it should be white, but my phone looks normal. There's an LED display board outside the Convention Centre which is now green, but as I sit at my computer typing this, the white background is just white. I guess it depends on the exact colour spectrum of the pixels.

I'll by trying to catch a spectrum tonight using my Public Lab Spectrometer http://publiclab.org/wiki/spectrometer - I'm expecting to pick up a couple of strong "notches" in the white light spectrum. I'll post here when I've captured a useful spectrum.

(For the sceptics: There is some “real science” behind these glasses, which differentiates them from other tinted sunglasses which have been promoted as "cures" for colour blindness – e.g. see: 

http://www.smithsonianmag.com/innovation/scientist-accidentally-developed-sunglasses-that-could-correct-color-blindness-180954456/?no-ist )

Affordable (Free!) 3D Modelling Software - A 5-Minute Review

When I started my adventures in the 3D printing world, I was using Alibre Design http://www.alibre.com/ as my main 3D modelling software. While I still have a valid Alibre licence, they have been taken over by 3D Systems (as you will see straight away if you click on the Alibre link above), and the software has morphed into "Geomagic Design", which has different features and licensing terms, and it has been increasingly difficult to migrate my Alibre licences onto new computers, running new operating systems. I thought it was time to look for a new CAD modelling software system to generate designs to feed my 3D printer.

There are many, many free and low-cost 3D modelling software options available, so where to start? Well, a good place is to list my must-haves and nice-to-have features:

Must-Have:

• I am looking for something that will design "mechanical" components, rather than "free-form" modelling (i.e. a mechanical CAD system (MCAD), rather than an artistic "clay modeller")
• Parametric modelling - e.g. the ability to edit a dimension and have the model "rebuild" itself (e.g. change the size and spacing of a group of bolt holes) 
• True "solid modelling", not "surface modelling" capabilities - e.g. I need to be able to insert a hole or cut-away, and have the internal volume recognised as a solid rather than a void
• Precision modelling capabilities - I need to be able to model to a fraction of a millimetre (even if my 3D printer's precision / tolerance are not quite up to the task sometimes!)
• Familiar UI layout / functionality / workflow - I have used various MCAD software such as Alibre, Solidworks, etc for many years, and their UI and general functionality suits me, and I don't see any need to lean a completely new way of working to achieve the same goals; I realise I will need to learn new icons and menus etc, but I am looking for the same overall workflow concepts such as Create a Sketch / Extrude / Fillet / etc
• Runs on Windows 10 (all of my home Windows machines have now been upgraded to Windows 10)
• Exports models in STL format
• 100% legal for personal / hobby use - I've been down the pirate software option, and I've used "extended trials" and "student licences" and so on, but I want to "keep it clean" from now on

Nice-To-Have:

• Import / Export a variety of industry-standard CAD formats (e.g. IGES, STEP, etc)
• Assembly Modelling (build assembles of multiple parts, to check fit and interference, etc)
• Runs on other platforms (e.g. Chromebook, Android tablet, etc)
• Will run without needing to "install" any software (I don't mind "installing" software on my own computers, but work policies prohibit the installation of software on the company's computers)
• Legal for limited work-related use (I would sometimes like the ability to create simple models for finite element analysis )

Alibre Design still works very well for me, apart from the licensing / migration issues, so it's time for me to move on. SketchUp http://www.sketchup.com/ doesn't quite cut-it - it's a terrific package for what it does, but it falls short on the precision MCAD capabilities. After doing an exhaustive search (i.e. a few quick Googles), here's what I came up with for closer consideration:

Onshape

https://www.onshape.com/

Onshape advertises itself as "the first and only full-cloud 3D CAD system that lets everyone

on a design team simultaneously work together using a web browser, phone or tablet" - and it seems to be true. Forget what you might think about Cloud software, and how slow it surely must be - Onshape has a pretty full set of professional modelling tools, and runs really well in a browser on even modest hardware such as a Chromebook, and it has native apps for iPad and Android tablets.

Onshape running in Chrome browser on Windows PC

Native Onshape app on Android tablet 

Capabilities include a wide range of import / export formats, assembly modelling, and so on. It's missing a few high-end features, but it is still undergoing active development (automatic 2D drawing generation is coming soon, for example).

The software designers come from the team that developed SolidWorks, and it shows in the toolset and UI design - if you have previous experience with professional MCAD software, you will feel at home very quickly.

What is truly remarkable, is that all of this capability is available free for hobby / personal use: https://www.onshape.com/features-and-pricing

You get access to ALL of the modelling tools for free - the only real limitation for the free account is the amount of Cloud storage space (5 GB for free accounts vs 100 GB for paid "Professional" accounts) - being a Cloud-based system, all of your models HAVE to reside on the Onshape cloud-store, but you can export models to your own file storage. 5 GB should be ample for all but the most ardent hobby modellers, though. In addition, you are limited to having 5 concurrent "Active" documents open at a time. For most hobby users, this won't be an issue - there is no limit on the total number of models you can have, but you may need to toggle some of them to be "Inactive" to free-up a new "Active" model. (Note that a "Document" can be a full assembly, with all of its parts, so you can have a lot of "Active" content at any one time!)

My only real reservation is that being proprietary software, there is always a chance that the owners might decide to abandon the free personal licence model at some future date, leaving me without free access to my models. However, their FAQ https://www.onshape.com/faqs suggests that there is no intention for this to happen, so I'll give them the benefit of the doubt:

Q:  Will Onshape ever change or restrict the Free plan?

A:  Although we cannot guarantee that there will never be additional differences between the Free and Professional plans, we expect that CAD modeling, drawings, and data management capabilities will continue to be fully available under the Free plan.

All in all, if you are looking for a good 3D modelling capability, you HAVE to take a look at Onshape!

FreeCAD

http://www.freecadweb.org/

FreeCAD is a totally free, open-source 3D parametric modeller. It seems to be the best-developed open-source 3D MCAD modelling software I have come across, and it is still being actively developed and supported. As such, it has a large user community, and it is likely to be around for a long time to meet your needs. It is available on Windows, Linux and Mac, so will work for most PC users (but no Chromebook or mobile app as yet).

It's part-modelling capabilities arr pretty comprehensive (certainly adequate for my needs), and being open-source (with support for Python scripting), it has plug-ins / add-ons / extensions for a range of other software systems, such as Assemblies, 2D drawings, rendering, BIM / IFC, etc.

FreeCAD on Windows PC

In all honesty, I would have been perfectly happy with FreeCAD if it wasn't for the fact that it needs to be "installed" on Windows computers, which my work will not permit. I was looking for something that I could access occasionally at work, which is how I came across the cloud-based browser-accessible Onshape. However, if you're looking for 100% free, open-source 3D MCAD software, FreeCAD seems to be the pick of the bunch for now.

AutoDesk Fusion 360

http://www.autodesk.com/products/fusion-360/overview

The AutoDesk brand should need no introduction, but Fusion 360 might not be familiar to you. Basically, Fusion 360 is a professional-quality cloud-based 3D CAD/CAM tool, which supports both Mechanical and Free-form modelling. If you're familiar with Inventor, then you will understand Fusion 360. While it is a cloud-based service, it does require an application to be installed on your PC (Windows and Mac are supported) - it does NOT run in the browser, so other platforms (Linux, Chromebook, mobile, etc) are nor currently available options.

Fusion 360 UI on PC

The licensing model is rather unusual. AutoDesk has long offered free or very low-cost Student Licences, as long as you have a valid student ID, but these would expire after some period, and you would then be "strongly encouraged" to upgrade to a full licence. Fusion 360 is different:

As well as the traditional free 3-year Student licence, AutoDesk offers http://www.autodesk.com/products/fusion-360/try-buy a free 1-year "start-up license" for "hobbyists, enthusiasts, makers, and emerging businesses that make less than US$100,000 in revenue per year". At the end of the 1-year term, you can reselect the start-up entitlement as often as you want (and as long as AutoDesk continues to support this licensing model). 

If you are familiar with AutoDesk products (especially Inventor), and especially if you want 100% compatibility with an AutoDesk work environment for example, then Fusion 360 is well worth a look. If you don't have a history with Inventor and other AutoDesk products, you might find it a bit more than you need, but then you only need to learn how to use those parts of its comprehensive tool-set that interest you. Going with an AutoDesk product has the advantage that there is a huge global Inventor user-base, and you can pick up any number of "How To" books from your local book-store (most of which should also apply to Fusion 360), so getting training and support is a no-brainer. 

And since it's free and legal (for now, anyway), why not give it a try if your interest is piqued?

And the winner is ......

Well, for now, it's almost a dead-heat. 

I really, really like Onshape - it works well, offers ALL of the features I'm interested in, and is truly multi-platform. My only qualifiers are the fact that it is Cloud-based (so won't work without an Internet connection) if that worries you, and the fact that it is proprietary software, and they might change their personal / hobbyist licensing terms one day. (I'll probably keep using it as long as it's free). In my view, Cloud-based software is probably the way of the future, and I have access to an Internet connection almost all of the time. The ability to view / refine models on any device at any time is a real plus (e.g. put the finishing touches on a design using your tablet while you're on the bus home after work). 

Otherwise, FreeCAD will also stay in my portfolio - partly because it's very good, and partly as a back-up in the event that Onshape is no longer available to me. It does MOST of what I want, but it isn't quite as polished, and it won't run on all of my devices (I can't install it on my work computer or my Chromebook, and I can't access it on my Android tablet, for example).

In third place for me is Fusion 360 - but mainly because it's a bit of a sledgehammer to crack a walnut as far as my needs are concerned - but if you have a track record with AutoDesk software generally (and Inventor in particular), you may well want to take a look.

For now, I'll give a Points Decision to Onshape - I'll post an update after a few months use to let you know if my feelings have changed.

Interested in getting into 3D printing, but don’t want to spend a lot?

How about AU$246.28 (plus postage) for a fully assembled, ready-to-go machine?

The TinyBoy Mini 3D Printer is a fully assembled machine designed by Parker Leung of Tiny Boy https://github.com/HKCOTA/TinyBoy as an open design easy to use 3D printer.The Mini Fabrikator by TinyBoy was designed around a concept that by 2016 every student should have the opportunity to have a 3D printer on their desk.

The TinyBoy is available on-line from HobbyKing for only AU$246.28 (at the time of writing): http://www.hobbyking.com/hobbyking/store/__80708__Mini_Fabrikator_3D_Printer_by_Tiny_Boy_Transparent_AU_230V.html 

(Postage is extra, and ranges from AU$82 to AU$169 for delivery to Australia.)

The machine is only 150 mm x 150 mm x 220 mm, and the build volume is fairly small (80 mm x 80 mm x 80 mm) so it can only make small components.- but still, at that price, why wouldn't you buy one?

Some more night-sky time-lapses with ZWO ASI120MC camera

My ZWO ASI120MC astro-camera Quick Review shipped with a 2.1 mm 150-degree fish-eye lens, which is good for doing "almost-all-sky" video / time-lapse photography pointing straight up. It has the dynamic range needed to be able to shoot both day-time and night-time skies.

It will also take other standard CS-mount CCTV lenses. I bought a 6 mm - 15 mm zoom lens for $20 on eBay, which is good for wide-field shooting when the camera is mounted "piggy-back" onto my telescope, or mounted on a tripod.

Here are a few night-time time-lapse videos which I shot to give a sense of what it can do.


The first video is a time-lapse of the "All-sky" view looking straight up with the 2.1 mm fish-eye lens (150 degree horizontal FoV). The video was shot using 5-second frame exposures, set to default 50% Gain, for 210 seconds of actual elapsed time. (Video shot at 8:39 pm 27 May 2015 in Brisbane; showing a very over-exposed Moon in the top right, and the Southern Cross and Pointers in bottom-centre of view.) Note: This sequence looks quite dark when viewed in a "window" on this page, but you can see more detail if you go full-screen.

Next comes a time-lapse looking almost due south, again with the 2.1 mm lens, using 30-second exposures @ 50% Gain, for 400 seconds actual elapsed time. (Shot at 8:52 pm 27 May 2015 in Brisbane; over-exposed Moon in top right; centred on Southern Cross and Pointers.) You can see a lot more stars and nebulosity with the longer frame exposures - e.g. hints of Eta Carinae and the Running Chicken.

Finally, here is a time-lapse looking south with the 15 mm CCTV lens, using 30-second exposures @ 50% Gain, for 600 seconds actual elapsed time. (Shot at 9:23 pm 27 May 2015 in Brisbane; centred on Southern Cross and Pointers.) The background sky is very light with this sequence, so I would probably get better results if I tweak the exposure settings; and I'm not sure that I got the focus quite right. Still, the amount of detail and faintness of the resolved stars isn't bad.

How to buy a second-hand telescope

So … you’re interested in getting into backyard astronomy, and you’re thinking of buying a  second-hand telescope - where do you start? Used telescopes come up for sale all the time on eBay, GumTree, garage sales, second-hand dealers, etc, as well as on Astronomical forums such as Ice In Space http://www.iceinspace.com.au/forum/forumdisplay.php?f=27 and Australia Astronomy Buy and Sell http://www.astrobuysell.com/au/index.php . Many of these telescopes were bought by other novices (just like you!) who bought a telescope and then discovered they didn't have the knowledge or interest to sustain the hobby - you can benefit from their mistake by buying a telescope at half the recommended retail price or less, but you need to be able to pick the gems from the junk.

How does a novice go about evaluating a used telescope to decide whether to buy?

Do you have any experience with telescopes, or do you have a friend who has some knowledge? It is a LOT easier to buy a used telescope with confidence if you know what to look for. If you have no prior experience with telescopes, you may have no way of knowing whether the telescope which is offered for sale is any good at all, or is in fact a complete dog. I am not going to offer you any tips for how to judge the quality of a telescope other than by looking through it and assessing the quality of the image, which is ultimately the only thing that really matters.

If you don't have any experience with telescopes, and can’t inspect with a friend with some experience, the following tips may not make much sense.

First and foremost, do your research so that you know what sort of telescope you are looking for, and the relative strengths and weaknesses of each type. Do you want a long focal length (high magnification) or short focal length (wide angle) telescope? Do you want maximum aperture or maximum portability? Will the telescope be used mainly for visual or photographic use? Do you want a GoTo mount, or will manual pointing be OK? A lot of second-hand telescopes are on the market because the owners simply don’t know how to use them, so you may not get much useful advice from the seller.

Note that there is no single “best” telescope, they all have their strengths and weaknesses, and buying any telescope is therefore a compromise. There is a truism that “the best telescope is the one that you use the most”, so think about where you will store it, where you will use it, and how you will move it around.

A big Dob will give jaw-dropping views of deep-sky targets, but can be cumbersome to store and move; a modest refractor or Cassegrain (80 mm - 150 mm aperture say) on a computerised GoTo mount can be a much more portable instrument, but will lack the light gathering power of a big Dob. Intermediate sized Schmidt-Cassegrains (200mm - 250mm aperture say) are considered to be wonderful all-rounders, but are relatively expensive. If you succumb to the backyard astronomy bug, it is inevitable that you will contract Aperture Fever, and you will be on an endless pursuit for bigger and better telescopes. I would suggest that a first-timer should consider a quality instrument which is convenient and portable as a first telescope, as it is likely to be used more often than a big heavy cumbersome “light bucket”.

If possible, I take a couple of my best eyepieces with me for the inspection, a 10mm - 20mm diameter chrome ball bearing (which I’ll explain below), and a torch. A lot of used telescopes are sold with only one or sometimes no eyepieces, and it is pretty hard to judge the condition if you can’t look through the telescope! Sometimes, the eyepieces that come with entry-level telescopes are quite ordinary quality, and a decent eyepiece will show the telescope to its best advantage. I would take a good wide-field 10mm and  25mm eyepiece (or thereabouts), and possibly a 6mm and a 32mm as well.

I prefer to inspect in daylight hours if possible, because it's a lot easier to judge the condition in good light, and you can get a good feel for the optical quality by looking at a distant building or tree. For astronomical use, the ultimate test is a star test, and if I was spending a lot of money, I would want to do a night-time inspection before sealing the deal, if possible. However, Murphy’s Law will probably conspire to make it cloudy when your dream telescope is offered for sale, and you won’t want to let it slip away. A star test can be simulated in full sunlight by putting a chrome ball bearing in the sun about 20 metres away and pointing the telescope at it. The image of the sun on the ball bearing should be a brilliant pin-point of light, which simulates a star in broad daylight. If it is cloudy, or at night, shine the torch on the ball bearing to create an artificial star image.

Ultimately, as long as the optics are good, the telescope should be usable. I wouldn't buy a telescope with poor optical quality unless it is to get parts for tinkering - if you don't have good knowledge and technique, it can be very difficult if not impossible to get a good image from a telescope with dirty misaligned mirrors and lenses.

A little bit of dust on the outside of a refractor or Cassegrain, or on the primary and secondary mirror of a Newtonian, is not necessarily a big problem, but I would walk away from any telescope which has a lot of dust inside the closed tube of a reflector or Cassegrain, or any telescope with a lot of fungus on any of the optical elements. I would also avoid any telescope which shows a lot scratches on the lenses and mirrors. It is possible to clean dust and even fungus from lenses and mirrors, but they are also easy to damage if you’re not careful. It’s very important that you can re-assemble the telescope precisely aligned if it needs to be pulled apart for cleaning and refurbishment, so don't think about undertaking this unless you have done your research first.

If the telescope is clean and tidy on the outside, that indicates the optical quality is PROBABLY in fair to good condition, but check anyway. Shine a bright torch down the tube, to see how clean all the elements are. A little bit of dust is not a big problem, but thick films of dust or other gunk are something to be wary of. I’m not too worried if the outside of the telescope tube and mount have a bit of dust and even light rust (especially for an older telescope), but very poor external quality is again a sign that the telescope has not been cared for, and this could affect the optical quality as well.

If the telescope looks OK, set it up to point at a distant target (a tree or building on the horizon is ideal), and check out the image.  Note that if it is a warm day in particular, the air will shimmer from thermal currents, and the image will wobble. Try to avoid pointing over hot surfaces such as roads, building roofs etc, as these tend to generate the strongest thermal currents. A distant target over trees will generally give a more stable image than over building roofs and roads, but of course, you will be limited by the situation where the telescope is offered for sale.

How does the image look - crisp and sharp from edge to edge, or is it blurry and hard to focus? If the general image looks OK, I would then use my ball bearing “artificial star” as the final test - you should see a brilliant pin-point when it is in focus, and this should turn into a nice-round donut with a black hole when you focus slightly in and out. If you can’t get a nice pin-point in focus, and nice donuts when slightly out of focus, this indicates an issue with the alignment of the optical elements (collimation). Unless you know how to collimate a telescope, I would walk away at that point. Collimation is quite easy for some telescope types (Newtonians and Schmidt-Cassegrains) as long as it is not too far out of alignment to start with, but much harder on refractors and Maks). If you know what you’re doing, you might even be able to collimate it on the spot, but if it’s badly out of collimation and you don't know what you’re doing, walk away.

Assuming the telescope comes on a mount, how does it feel - is it smooth and easy to balance, or does it grab and jerk as you move it? Does it hold position firmly when you find a target, or does it slip and droop? There is nothing more frustrating than trying to go stargazing on a mount which won't let you find and hold targets!

If it is a powered mount, does it work properly? Again, a lot of used telescopes are sold by people who have no idea how the powered mount should operate, so it is worth checking before you go whether they know how to power it, whether it has batteries, etc. If they don't know, it will be difficult to test the mount unless you are familiar with how that type works, and can bring along a suitable power supply to test it. It can be tricky to fully test a computerised GoTo mount in daylight hours, but as long as you can get power to the two drives, and move it left and right, and up and down, there is a good chance that the mount is more or less fully functional.

If the mount is in very poor condition (or missing altogether), most telescopes can be mounted onto any standard mount, so you can consider buying the telescope for the optical tube alone, and budget for a separate mount.

Samsung Gear Live & Android Wear - A Quick Review

As a lover of all kinds of techie toys, I’ve been intrigued by the idea of smartwatches since they were first introduced. I even bought a first-generation Sony SmartWatch when they were being heavily discounted not long after they were first introduced in 2011/12. It worked fine (indeed, it still does), but it’s pretty limited in what it can do. It was an interesting concept, but it clearly needed a lot of work, and it didn't take me long to work out why the first-generation smartwatches never really captured the world’s imagination.

But move along to late 2014 / early 2015 (a couple of years is a couple of generations when it comes to consumer electronics!), and Google’s announcement of Android Wear  http://www.android.com/wear/ (and of course Apple’s pre-announcement of the as-yet vapour-ware Apple Watch http://www.apple.com/au/watch/?cid=wwa-au-kwg-watch-com )

Now THIS has the potential to really change things - the two biggest names in mobiles getting seriously behind the whole concept of “wearables” and smartwatches.

In Australia right now (January 2015), there are only three Android Wear watches officially available through the Google Play store https://play.google.com/store/devices/collection/promotion_5000135_android_wear_au - the LG G Watch (Google Play price AU$249) and G Watch R (AU$349), and the Samsung Gear Live (AU$250). The Moto 360, Sony SmartWatch 3 and Asus ZenWatch are not on sale through the Google Play store or most mainstream retail outlets yet (although I believe you can get the Moto 360 in a few shops, if you know where to find them).

Even though Android Wear devices have only been on the global market for a few months, I was pretty surprised to see the Samsung Gear Live listed at OfficeWorks for the knock-down price of AU$188:

http://www.officeworks.com.au/shop/officeworks/samsung-gear-live-black-sgearliveb?searchTerm=samsung%20gear%20live

This was the one I had been looking at anyway, as it adds a heart-rate monitor to the sensors available on the cheaper of the two LG watches. Naturally, I hot-footed it to my nearest OfficeWorks, but couldn't see them anywhere. When I asked at the counter - yes, they had them (plenty of them) in a locked cabinet behind the counter, but none on display. (So I guess the reason OfficeWorks have dropped the price is because they aren't selling many - and the reason they aren't selling many is because they hide them from view, and you have to ask to even be aware that they have them.)

I got it home, charged it and paired it to my Nexus 4 (running stock Android 5 Lollipop), and it all worked seamlessly. The first thing it did after pairing was to upgrade its own firmware – and a few days later, it did so again - it now reports that it is running Software version 5.0.1.

I have to say this thing is about a hundred light years ahead of my previous smart-watch (1st Gen Sony SmartWatch), for not much more than I paid for the Sony – both in build quality, and functionality and features. I suspect that's at least partly because the Android Wear platform is so much more "mature" and capable than the limited functionality that the Sony could offer a couple of years ago, but of course the hardware has moved on a lot in 2 years as well. I love the integration to all of my stock Android apps. (Did you know that when you start the Camera app on your phone, you get a remote release button that automatically pops up on the phone? Neat – but I'm not sure when I'll ever use it!)

First impressions:

The watch fits comfortably, and even though it’s quite big physically, I don’t notice it once its on. (My “real” watch is a Tag-Heuer diver’s chronograph, so I’m quite used to a big watch - the Samsung is comparable in physical size, but a lot lighter.) I don’t have any problems with the strap fastening system that some people complain about (pins that plug into holes, rather than a conventional clasp or buckle ), and it hasn’t once threatened to come undone.

The display is bright, colourful and sharp - indoors, anyway. It’s a bit difficult to read in full sunlight (depending on what watch face design you use - some are more contrasty and therefore daylight-readable than others. (Recent updates in Android Wear 5 mean that you can temporarily brighten the back-light using “Sunlight mode”, and this helps a bit, but it’s still a bit hard to read in bright direct sunlight.)

And of course, there are dozens of downloadable watch face designs to choose from https://play.google.com/store/search?q=android+wear&c=apps&docType=1&sp=CAFiDgoMYW5kcm9pZCB3ZWFyegIYAIoBAggB , or you can design your own with a suitable app. I use Intellicom Watch Faces for Android Wear https://play.google.com/store/apps/details?id=no.intellicom.lswatchface , and I’ve designed this face, which is easy to read, and shows me the time and date, as well as the remaining battery charge on both my watch and phone:

I use the “Display always on” feature, which shows a “muted” watch display (to reduce battery drain) when you’re not actually looking at it - this is the “muted” version of my watch face:

I get through a full day even with the display always on. One thing that really bugged me with the old Sony was that you had to touch the watch to activate the display, which really limits its functionality as a watch, in my opinion. The muted display option in Android Wear does the job for me, while still giving me acceptable battery life.

Of course, Android Wear’s big party trick is voice-control - raise your watch to the normal viewing position, and say “OK Google” to activate it, and then tell / ask Google what you want it to do (e.g. "Remind me to ...", "Set a timer for ...", etc). It actually works very well - I get near-100% accuracy for my voice controls, even outdoors, or in moderately noisy environments. (If there's a lot of background noise, it can help to bring the watch closer to your mouth, but generally, it’s not necessary.) Of course, you do feel a bit of a dork talking to your watch, but I guess we’ll all get used to people talking to their wrists soon enough. If it bothers you, you can still access all functionality by tapping and swiping on the display, and the touch interface is very intuitive, especially if you’re already familiar with Android 5.

Out of the box, your watch will present a lot of pre-loaded shortcuts, offering to “Send an sms to Jim” (who’s Jim?) or “Ask Eve if she is available on Friday night” (who’s Eve?) These are just prompts to help you get used to how you're "supposed" to use the watch, and they go away after a while, after you have started to interact with the Android Wear interface, when it thinks you’ve got the picture. Even when they’ve gone, if you tap and scroll down, you will see the "prompts", which can remind you of some of the sorts of things your watch can do, but you might have forgotten about.  

Some of them are actions in themselves which require no further action (e.g. "Show me my steps" or “Show me my heart rate”), while others just start the next part of the instruction sequence, but still require additional voice input (e.g. "Send a text", after which it will prompt you first for an addressee, and then for the message content).

There is a growing collection of apps and games which you can load onto your Android Wear device. In many of these apps (especially the Google apps, which are heavily integrated), the main app resides on the phone, and there is an augmented "extension" which automatically uploads to the watch, and the user doesn't have to do anything to enable this – if you have a Wear-enabled app on your paired phone, the watch will automatically get the "extension" from the phone without you having to consciously do anything to enable it.

E.g. cast a YouTube video from your phone to a Chromecast on your TV, and the YouTube player controls automatically pop-up on your watch, so you can pause, advance etc from your paired watch without needing to touch the phone. Or play music from your phone to your car's paired Bluetooth audio system or a Bluetooth speaker, and control it by talking to your watch (without needing to touch or even look at the screen), while your phone stays in your pocket: "OK Google ... play Rolling Stones"

THAT'S what Android Wear is really all about!

There is also a growing collection of stand-alone apps and games for Android Wear, which have no UI on your phone. (You still install them via the paired phone, but that’s it - the only display / interaction is via the watch.) Some of them are OK, but ultimately, they’re all going to be limited by the small display size. (Which all seems  a bit ironic to me - we’ve seen a trend for steadily increasing smartphone displays, from 3 ½ ” to 4” to 5” to 6” and even bigger - and now we’re going to start relying on a 1 ½” display?!) Most of the games and apps that you’re already used to are much more usable on your phone. Playing games and running productivity apps on the watch  isn't really what I bought my Samsung Gear Live watch for - the real power of an Android Wear device to me is integration / extension of your smartphone's capabilities to a second-screen on your wrist. Nevertheless, it will be interesting to see what comes up in the next few months - I wonder what the first “killer app” for smartwatches will be?

I’ve heard lots of reports of “abysmal” battery life on pretty well all smartwatches (with the exception of the Pebble series, which use a B&W e-ink display). I get through a full day easily, with about 30% charge or more remaining, which is pretty much the same state my phone is in when I go to bed. I can live with that - sure, 3 days or more of battery life would be nice, but it’s never left me embarrassed by running flat part way through the day or evening. My nightly routine now means I plug both my phone and watch in for a charge, and I don’t see that as being a deal-breaker.

Speaking of charging - the Samsung battery charger adapter isn’t very nice - it’s a cheap-feeling click-on plastic thing, and if you lose it or break it (or forget to pack it for a trip), you’ll be unable to recharge.

Wireless charging would be much nicer, but I guess that’s what you get for buying the cheapest Android Wear watch. I don’t think it’s particularly likely to break with sensible handling, and it lives by my bed, so there's not much risk of it going astray. (Given that I get comfortably through a full day, I don’t need to take the adapter to work for top-ups - but I  might pick up a spare one anyway, just in case …)

One nice feature that arrived with Android Wear 5: you now have the ability to download music from your phone to the watch, and pair your Bluetooth headphones directly to the watch, so that you can use it as a music player when you don’t have your phone handy. I always have my phone in my pocket, so while I’ve tested it and it works fine, this isn’t a feature that I’ll use much, but I can imagine it will appeal to people, who like running with a minimum of devices to weigh them down. (Of course, you’ll have no phone or messaging capacity if you run without your phone, but at least you can still listen to your music and tell the time, as well as get updates on your step-count and heart-rate.)

So … is it a must-have?

Well, for most people, probably not - yet. (Unless you’re  tech-junky like me! At $188, the Samsung Wear Live is probably the cheapest way for experimenters and early adopters to experience Android Wear for themselves.)

It doesn't tell me anything that my phone doesn't tell me, but it does a lot without having to reach for my phone. I can discretely scan incoming calls, emails and text messages from my wrist, and decide whether I need t respond immediately. My phone’s battery life is significantly better than it was. Sure, some of this might be battery improvements in Lollipop 5.0.1 compared to KitKat 4.x, but some of it is certainly due to not actually reaching for my phone nearly as often as I used to.

I’m looking forward to seeing what new features and apps get added over the next few months.