Sure you can buy ringtones from Apple, you can even make your own if you know how.
The latter is what I did and it’s proved to be pretty popular with people at the same time as confusing them something rotten…

Remember the old days of dialling up to your ISP with your modem? That screaming fax machine type sound? ah.. the memories…

Well that’s my ringtone!

When your phone rings the less tech savvy think I’m somehow receiving a fax, while my fellow geeks think it’s pretty cool and demand a copy of the file!

So here it is:

(to download you MUST right click and save as):
RIGHT CLICK here to download my iPhone “modem” Ringtone

Download the file and drag it onto iTunes.
The next time you sync your iPhone make sure you sync this ringtone as well.

If you like this ringtone please use the Digg link below & Digg it up!

warning: it’s pretty loud!

As I mentioned in part 1, I decided to make some real world measurements of the performance of the solar panel and also the power requirements of the iPhone 3G.

I hooked up a DC power monitor to a 12 volt battery and for a period of exactly 1 week I charged the iPhone exclusively from the 12V battery via a Kensington car charger. In 1 week of my normal use, (ie with WiFi and bluetooth switched on 24/7, email checks every 15 mins, some light browsing and probably 3 or 4 hours of calls) the phone used 43.5 WH (watt hours).

(To publicly answer those who have asked, the iPhone charges at 3.5 Watts continuously but slows down as the battery gets close to full.)

So how did my little 2.4 Watt test solar panel fare? I measured the output over a period of 7 days although I will point out that due to the time of year (sun low in the sky and thus a shaded panel) and a few other factors the panel only had direct access to sunlight for a few hours per day, so it could do better…

Day 1 (10am – 4pm = 6 hours): 0.1 Watt/Hours (heavily overcast)
Day 2 (10am – 4pm = 6 hours): 0.1 Watt/Hours (heavily overcast and raining)
Day 3 (10am – 2pm = 4 hours): 1.8 Watt/Hours (blue sky, v few clouds)
Day 4 (12pm – 3pm = 3 hours): 0.9 Watt/Hours (blue sky, some cloud)
Day 5 (11am – 3pm = 4 hours): 0.9 Watt/Hours (lightly overcast becoming clear blue later)
Day 6 (10am – 2pm = 4 hours): 2.1 Watt/Hours (blue sky, v few clouds)
Day 7 (12pm – 2pm = 2 hours): 0.6 Watt/Hours (blue sky, some cloud)

That’s a total of 6.5 Watt Hours in 7 days. Due to the limited number of hours the panel was setup I suspect I could get another 30% on top of that figure so about 8.5 Watt Hours in 1 week from a 2.4 Watt rated panel.

The phone used 43.5 Watt Hours in 1 week so I need a panel about 5 times more powerful than my little test panel, which would be a 13 Watt rated panel…

But of course this is the UK, in winter. I could save money and buy a smaller solar panel along with a decent sized battery and fully charge it over summer. In the winter the iPhone would slowly deplete the battery as it would be taking more current out than a smaller panel could put in, but as long as the battery had enough reserve to make up the difference until spring I’d be ok. Then over spring/summer the panel would generate more power than the iPhone needed during that time and thus replenish the battery. At least that’s the theory…

So part 3 will be some calculations (yes more math, sorry!) to see what size battery I might need in order to buy a cheaper less powerful solar panel than 13 Watts. Maybe the sums won’t add up or the battery would have to be so big it would be cheaper to buy the more powerful solar panel…

To power something like an iPhone from solar energy you need at least 2 things:

• A solar panel to convert light into electricity
• A battery to store that electricity until your gadget needs it to charge

The battery is important as we only get a few hours of daylight per day and that’s not necessarily when I want to go outside and charge the phone.

There are a few off the shelf products you can buy to do this, one name that seems to come up quite often is Freeloader.

This £30 gadget is a solar panel and li-ion battery all in one neat little package. The solar panel charges the internal battery, and you plug in your iPhone to charge it from said battery whenever you’re ready. According to the spec the Freeloader has a 1000mAh battery that it can charge from its 120mAh solar panel in as little as 8 hours. This is where I spot a couple of problems…

Problem 1 is that the capacity of the battery in the Freeloader is smaller than the capacity of the battery in the iPhone. The iPhone has a 1400mAh battery but the Freeloader only has a 1000mAh battery. This means that a fully charged Freeloader cannot fully charge your iPhone, simple maths tells us that it can only charge an iPhone to 70% from flat. That’s not bad though if you don’t use more than 70% of your iPhone battery in a day.
Problem 2 is the Freeloaders solar panel takes 8 hours to charge its internal battery. Now, research has shown me that this sort of rating is a best case scenario measured during what is called peak sun hours. So it takes 8 peak sun hours to charge up the Freeloader. Don’t worry about the technical details of what a peak sun hour is, but know this, in the UK, on average we only get 4 peak sun hours per day in the summer and that drops off to just 1 per day in winter. So in the summer it will typically take 2 days to charge up the Freeloader and in winter it will typically take 8 days! and remember that the Freeloader only represents a 70% iPhone charge. 8 days to get 70% worth of an iPhone charge is just not practical…

So the Freeloader is a great product, but it’s just not up to the task of powering my iPhone 365 days a year…

So I’m going to have to come up with a DIY solution…

Most solar panels on the market are 12 volts so I will buy one of those, connect it to a 12 volt battery, and charge the iPhone from the 12 volt battery using a standard iPhone car charger cable.

Sounds straightforward enough.

So how powerful a solar panel do I need and what sort of capacity will the 12 volt battery need to be?

Lets do some maths…

I need to put 1400mAh (1.4Ah) of power into a 5 volt iPhone battery every day.
Solar panels tend to be rated in Watts (which is voltage/current independent) so I need to convert these numbers to Watts.

Watts = Volts x Current

Watts = 5V x 1.4Ah = 7 WattHours

So to fully charge an iPhone from flat I need a solar panel that can generate 7 Watts per hour for 1 hour, 3.5 Watts per hour for 2 hours or 1.75 Watts per hour for 4 hours.

As I mentioned earlier, the wattage rating of solar panels is measured during peak sun hours, of which we in the UK only get 1 on average per day in winter. So according to the calculations above I need a 7 Watt solar panel if I’m to get the charge I need in winter, whereas I could make do with a 1.75 Watt panel in summer as we have 4 peak sun hours…

Solar panels seem to mostly come in 5W or 10W versions and as 5W is too small I need to be looking at a 10W panel. 10W panels seem to go for £40 or more on eBay. Calculations are one thing, but the real world is another so I need to be sure that a 10W panel is actually going to be enough. A 10W panel should generate 10 WattHours every day in winter (remember we get 1 peak sun hour per day on average) which should be more than enough but will it in the real world?

Assuming (for simplicity) that the real world performance of all solar panels is xx% of their rated performance I should be able to test my figures by buying a cheaper, less powerful solar panel and measuring the output. If it generates what is says on the box then great, if it only generates half as much then I’ll need twice as powerful a panel as my calculations said I would.

Maplins had a half price offer on a 2.4w panel, it was marked down to just £12.49 so I bought it.

I will connect it to an old 12volt battery I have lying around and measure how much charge (in WattHours) it generates every day using a special power meter. It should generate 2.4 WattHours per day on average in winter so lets see if it does over the next few days…

Continue Reading – My solar powered iPhone – Part 2

So I decided to try a simple test as I am currently learning how to develop iPhone applications that make use of the GPS. Using a 3rd party application to log the GPS co-ordinates from the iPhone, I cycled a 3.5 mile route through a suburb of London and exported the co-ordinates as a KML file and loaded the path into Google Earth. I then manually drew an accurate path in Google Earth of the same route.

As I was cycling, bear in mind that I made use of the pevement in places, as well as the road.

Basically the purple line in the video below is the path I drew manually and is as accurate as you could hope for. The white line is the path as determined by the iPhone GPS unit.

Click here to view the embedded video.

While a consumer GPS system will never place you to within a metre (as my manually drawn path does) I think the iPhone GPS unit is, overall, pretty accurate. Certainly it looks to me as though it would be up to the task of powering proper real time navigation software such as that typically found in car sat-nav units. I would imagine that car sat-nav units clamp the location to the nearest road using some sort of algorithm so slight deviations don’t affect them.

The chart below highlights the different generations along with the price (at launch), storage capacity, battery life (max battery life is for audio use only, minimum battery life is for video playback where available), colour selection (all colours available during that generations lifespan)

This pre-launch video makes for a very interesting watch, my favourite quote is by Seal (from 5:15 in) who says something that sums it up:

“Everyone is going to want to have one of these”

Click here to view the embedded video.

A few weeks ago I posted a link to a web based application that we wrote to test the download speeds on the 3G iPhone. So far 806 tests have been performed by users from all over the world.

The average 3G connection speed (ie filtering out the results from 2G or Wi-Fi tests) for each country, in order of fastest to slowest, is as follows:

For comparison the figures for 2G performance are:

Now, there are some limitations to our test methodology. We rely on the honesty (and intelligence) of the user to select the correct test (2G, 3G, Wi-Fi etc) based on their current connection as displayed at the top left of their iPhone screen. Some suspicious results (eg a download speed of 5Mbps on a claimed 2G GPRS connection) are filtered out automatically. In addition, our test server is located in the USA so connections to a server based in a users home country may well exhibit faster download speeds. However, as the majority of the most popular websites are based in the USA it’s still a valid test.

http://speedtest.lightsourcemedia.co.uk 

and run the test. 

Technically (and aesthetically) it’s a bit quick and dirty but it works. 

There are limitations in the accuracy as it contacts a server in the USA to do the test, so if you’re in the UK for example you may get a higher speed browsing to UK sites than you will on this test. But it’s a start and most servers (and iPhone users) are based in the USA, plus the limitation will mostly only factor into WiFi tests (which we’re not especially interested in actually) so it’s not a bad compromise.

Your help is greatly appreciated! 

Please encourage others to take the test, spread the link around, the more that do the better the stats will be.

We will post an analysis of the results on this blog and add a page to our site showing the average speeds achieved etc.

NOTE:  We would like to expand the test by placing our test file on servers in different countries.  Please contact us if you have a lot bandwidth to spare and can host the test file we’d sure appreciate it.

Sensors

• Accelerometer
• Proximity sensor
• Ambient light sensor

It’s a free download and allows you to manage your Wordpress based blog quickly and easily.

So,  first impressions?

Well, as a test I wrote this post using the app.  It seems fairly buggy, while taking screenshots and flicking between the various screens I’ve had a couple of instances where the app quit unexpectedly.

As the editing is fairly limited in terms of layout (pictures are easy to add but not exactly easy to move around) I created the post on the iPhone, then did my final adjustments using my Mac.  This is no problem and is to be expected but take note of the warning below…

IMPORTANT WARNING!

The app is native to the iPhone and uses its own database, not the online one that actually powers your blog.  This means the iPhone does not know if you update a post on your computer.  If you then decide to edit the post on your iPhone in future you are in effect editing an old copy of the post…  I learnt this the hard way when I edited the post on my Mac and then decided to add additional screenshots via the iPhone.  I didn’t notice that the iPhone was unaware of the changes I had made via the Mac, and when I added my screenshots and posted my update, all the layout changes I had made via the Mac were lost.  Thankfully I was able to use the revision feature in Wordpress 2.6 to revert to the previous revision.  I then hit the refresh page on the iPhone app, and updated the correct version of this post.  Incidentally, I can’t spot a way to access the revisions via the iPhone app.

Bottom line:  Make sure you hit that refresh button in the posts list before you edit any of your entries…

Screenshots

The “Home” screen:

The “About” screen

The first step is to add your blog, just fill in the appropriate info:

Your blog will then appear in the list on the “Home” screen

Tapping on a blog shows the posts and the important refresh button in the lower left:

Tap the icon in the lower right to create a new post or tap on an existing post to edit:

Add photos easily (note, they get added to the end of your post):

Selecting a post category is straightforward:

As is adding a new category:

The post status can easily be set between draft or published etc

The post date and time can be adjusted:

The post settings screen doesn’t contain much, mainly the opportunity to password protect the post:

The preview screen is very basic as it ignores your CSS: