Rick Hurst Web Developer in Bristol, UK

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Month: June 2010

Working on a dell mini 10

dell mini 10

I’ve bought a dell mini 10 netbook as a “fallback” machine for the road trip. I usually work from a macbook, but wanted a second machine, should the first one get broken/stolen/lost. Even though I already have a spare macbook, when I saw that the new dell mini’s boast up to 9.5 hours battery life, it dawned on me that it might be a better approach.

As well as the battery life, the machine is very small and light, so it is more practical for lugging around in a backpack, on the offchance that I might stumble across some wifi, or find a spare hour or two do some work in a cafe.

So the question is, can I actually do any serious work on it? Software-wise i’m sorted, with dual boot windows and ubuntu linux, plus virtualbox to run other servers from within either environment, and I could even run apple osx on it if I wanted. The keyboard is useable, but the trackpad feels awkward. I think it is absolutely fine for writing code on, but doing website layout and design is going to be awkward. When i’m not on the road, I can plug in an external monitor to get around that, but the point is to be mobile.

A massive plus is cost. This was only £200 before VAT, so that makes it almost “disposable”, at least compared to £1000 upwards for a macbook. This also makes me think that when the time comes to replace my macbook, maybe I ought to consider switching to ubuntu full time, and get a bigger non-apple laptop.

Using a Powergorilla to power and charge a macbook.

powergorilla LCD display

First test – does it charge at all?

Yes. Using the magsafe “sample” powertraveller sent me and with the power gorilla set to 16 volts, it does indeed charge the macbook. I’m very happy about that, otherwise this might have been an expensive experiment! This also confirms that the cable is suitable for charging, so therefore my previous experiment with the solar gorilla confirmed that it should have been charging, but didn’t.

Test two: how long does it last?

Starting from a half charged macbook, I plugged in a fully charged power gorilla. I wanted to see how many charges I got from it, if I unplugged it whenever the macbook battery is charged and plug back in again when it gets low. Simultaneously powering and charging the macbook drained the power gorilla before it had even completed the first charge. I’m not sure what to make of that – in theory the powergorilla has four times the capacity of the macbook battery – is the charging process so inefficient that most of that is wasted? I guess I have to factor in the fact that the macbook was also drawing charge whilst being charged, because it was running. I need to repeat that experiment with a sleeping macbook.

I tried again starting from a fully charged macbook, and fully charged powergorilla – I was also using the macbook, and got just over two hours before the powergorilla was drained, and the macbook status went from “charged” to using the internal battery. This is about the same amount of time I get from the internal battery. Once again, this is disappointing, as in theory the powergorilla has four times the capacity. I should point out that even the macbook (one of the older plastic ones) claims up to 5 hours battery life, in reality I usually only get about two and a half, as I tend to run a lot of stuff – virtual machines, photoshop etc. To continue the experiment I then carried on working from the internal battery until it was virtually flat. In total I got 4.5 hours – that’s combined total runtime from a powergorilla that claims 2 to 5 hours laptop power and an internal macbook battery that claims up to 5, so less than half in total!

Most importantly, this isn’t a full days work, and I need to allow for charging time too. The claimed maximum battery life is always higher than you get in reality unless you switch of wifi/ bluetooth, dim the screen and work with only a few lightweight applications. There are more details on expected macbook battery life here here. The newer macbooks and macbook pro’s claim more battery life, but via the grapevine i’ve heard that they still fall short of a days work when used under realistic load. Also these higher capacity batteries will require more charging therefore don’t necessarily solve my issues.

Will the power gorilla power/charge a macbook while it is being charged itself?

When it is being charged via the mains: sometimes. I think the battery has to have a certain amount of charge before it will output anything, while being charged. When/ if the indicator changes from the charge icon to 16v, it will start charging. Note that as the mains charger is 16V, the battery can only output 16v while it is being charged. So far it hasn’t worked while being charged from the solar gorilla. This is a pain – I was hoping that the powergorilla could permanently be hooked up to the solar gorilla when practical, to take advantage of any available energy, but it seems that while it is being charged, it won’t power the macbook.

How long does it take to charge from the mains?

I’ve not worked this out yet – definitely more than 3 hours, but last time I tried I went to bed before it was finished, but it was charged when I got up.

How long does it take to charge from the solar gorilla

Obviously this is weather/ sunlight dependent, and i’m in the UK during a predictably unpredictable summer. I’ll post back here when i’ve done it a few times.

Update: follow up articles:-

You know what I did last summer?

team rubber video shoot

Last summer I was freelancing for the lovely Team Rubber, when I overheard one of the film making dept say “Now we just need a skateboarder to skate the halfpipe..”. I immediately volunteered myself for the role. “Can you skate a halfpipe?” he asked. “Um.. yep, how high?”, I replied. “13 foot”. “..err.. (mumble)… can I come along and watch though?”.

I tend to work on projects with a local working copy on my laptop of whatever it is i’m working on, so pre-empting the current meme of working away from the office, I offered to go along to the shoot, help out where I could, learn about the video shoot process and work the rest of the time from my laptop.

The video shoot was on an old air base in wiltshire. I arrived early in the morning and couldn’t figure out how to get on site, so I circled the perimeter trying out various back roads and possible routes in, occasionally encountering other car drivers, eyeing me up suspiciously as I loitered. I eventually spotted some of the crew arrive and unlock a gate, and sure enough most of the cars I had encountered earlier turned out to contain runners, directors and extras.

The ramp was already set up and I was dying to have a quick go on it, but then the heavens opened leaving the uncovered ramp to get soaked. I prayed that the weather would clear up, as the shoot would have to be postphoned or cancelled if the rain continued. Fortunately it cleared up soon after, and became a scorcher of a day so I went and swept the surface water off the ramp to help it dry out quicker.

I climbed onto one of the platforms just to see what it would be like to drop in, but being considerably higher (4.5ft higher specifically) than anything i’ve skated before, there was no chance of me giving it a go, at least dropping in from the top. I skated it from the bottom, pumping the transitions to gradually get higher and higher up the ramp, but looking back at the embarrassing video clip I persuaded someone to film on my camera, I can’t have gone any higher than halfway towards the top. Fortunately, the ramp owner, and UK vert legend Pete King arrived to provide the goods.

Pete King air

3d model of the halfpipe

The plan was to use the skater as a reference for a CGI character, so the CGI guys set up a makeshift studio in one of the hangars and created a 3d model of the ramp. Pete was dressing in a rather fetching grey one-piece (“chroma key” suit) with white tape to use for CGI reference. As you can see from the photos, he didn’t disappoint with the skating – pulling some massive airs for the camera. These photos are not modified – he was consistently getting airs that high, and landing them most of the day, despite the blazing sun and being asked to repeat the sequence over and over.

Hangar studio

As if hanging around on an air base watching a skateboarder dressed in a lycra suit wasn’t surreal enough, the actors, now dressed as american GI’s, were bought in to encourage and heckle Pete, sometimes while he was there, sometimes when he wasn’t.

more air

Then the chopper arrived. Ever wonder why insurance companies have a problem with media types? Luckily i’m a software developer, so *cough* no chance of my car getting hit by helicopter-related flying debris on a film shoot..*cough*. I made myself handy by securing a nearby gazebo with breeze blocks before it (and the helicopter) took off again.

I can’t say I got a massive amount of work done as planned. Working from the hangar and my mobile office (car, with leisure battery + 3g phone), there was no wifi on site and I could barely get a mobile signal good enough for data, but the main reason was there too much exciting stuff going on to concentrate. I skated the ramp anytime it wasn’t being used – you can’t stick a halfpipe in front of me then expect me to concentrate on python and javascript! Thanks to Team Rubber for a great day out!

mobile office

p.s. you can see the final video here.

Experiments with the solar gorilla


Solar Gorilla on the roof

I read loads of reviews of the <a href="solar gorilla before taking the plunge and buying one. I payed particular attention to mentions of the macbook (being my weapon of choice). One thing I noted was that when using the solar gorilla with the apple airline magsafe adapter, the reviews all pointed out that this would only power, not charge, a macbook. I was wondering if this was a limitation of the adapter, or insufficient power. I read somewhere that it was the former, so decided against buying an airline adapter (I had plans to make my own 12v plug adapter to link up with my butchered magsafe adapter). However, after speaking to powertraveller, they said they could send me a “sample” magsafe adapter, which connects directly to the power gorilla.

My first attempt to use it (by sticking the solar gorilla out on the roof on a cloudless day, but setting sun), and the charging status read “charged” (starting from a charged battery), but after running for about half an hour, the sun went behind some houses and the status changed to show it running on battery, which was now pretty flat, so the macbook had indeed been running from battery the whole time.

The second experiment today in the back garden, starting from a 50% full battery, the macbook status read “not charging”. There are a few clouds around, but it is a rare fairly sunny june day. I think I can therefore conclude that the solar gorilla is not a viable charging or powering option for a macbook in a UK climate when used on it’s own.

One question still open is whether the sample magsafe cable has the same limitation as the airline adapter – i.e. is it supposed to charge? To work that out I will try it with the power gorilla (waiting for me at olivewood HQ). If that doesn’t work, I will cobble together the DIY solution mentioned before, to rule out wiring.

I have worked out that it is possible to have the solar gorilla charging my leisure battery, while I simultaneously power/ charge the macbook via my DC-DC converter. I’ve yet to work out what rate the battery is being charged vs drained! Another concern is that I seem to have one of the earlier generation of solar gorilla (it has a green, rather than red LED), which possibly suffers from reverse charging i.e. in theory if I leave connected to the leisure battery after dark it might drain it – still inconclusive though.

Another annoyance is that the solar gorilla will not even charge my iphone when connected to the usb port. This is probably due to the “fussiness” of the iphone, probably a fluctuating or insufficient voltage causes the iphone to declare “This accessory is not supported”.

Working from the VW dealership

One of the things I need to get sorted on the beetle before the road trip is an intermittent problem where the immobilizer won’t allow me to start the car. It lulls you into a false sense of security by starting the engine, then immediately cutting out, leaving you with a flashing bug/key icon on the dash. I’m getting the keys recoded (so that immobilizer recognises them), which should leave me with two working keys, and at the very least, help me rule out “faulty key” as a possible cause if it happens again.

I’m working this morning in the (very nice) coffee area in the local VW dealership. One of the main problems in being here is all the nice shiny vehicles and brochures hanging around. I have to avoid being seduced into leaving with a brand new vehicle and several years worth of debt..

Preparation – keeping a laptop charged on the move

I have been buying and experimenting with some equipment to help keep my laptop charged while i’m away from mains electricity. I have few tools at my disposal:-

Halfords Portable Powerpack 200

Halfords Portable Powerpack 200

It’s basically a 12 volt leisure battery with a lamp, 240 volt inverter and air compressor built in. I only got it because I inherited it with the car (the previous owner bought it to jump start the car when it had been in storage too long and the main battery had gone flat). It can charge from a 12 volt car socket or mains adapter, plus I am having some success charging it from a solar gorilla. The battery sais that it is 20ah, whatever that means in lamens terms.

Using the 240 volt inverter is incredibly inefficient, so only for “emergencies” really. More efficient is using the 12 volt output with the Trust DC-DC converter (below) that allows me to step up from 12 volts to the 16 volts required to run my macbook.

The obvious downside of this battery is that it is very heavy, only suitable for lugging around in the back of a car, so while it will be useful on a campsite with no mains hookup, i’m not exactly going to lug it into a cafe!

Trust 130W Multi Function Notebook Power Adapter

Trust 130W Multi Function Notebook Power Adapter

This is really useful – if I wasn’t a mac user, there would probably be a charger tip included with this, but due to licensing there isn’t. Therefore I had to take the DIY approach of snipping a section of cable from my spare apple power adapter (doesn’t feel good doing that, knowing they are about £60 to replace!). I also modified one of the tips to allow me to fit a section of wire with spade clips, to make it easier to plug in other adapters if necessary.

Amazingly this works – charging and powering the macbook. I need to do some proper experiments to see how many charges I would get out of the leisure battery.

It also has a USB port so I can charge my iphone from it at the same time.

More details on the dealer’s site.

Solar Gorilla

solar gorilla

This is a lightweight portable solar panel that will apparently charge a laptop. Covered in more detail here