Posts Tagged ‘mobile’

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Augmented reality for Hursley

Friday, November 6th, 2009

screenshot : click for better resolution imageOne of the themes at openMIC this week was augmented reality, and a topic that came up a couple of times was Layar.

Layar is a mobile app for Android and iPhone that lets you display location-based information overlaid on a real-time camera view.

For example, the screen normally shows a viewfinder-like view from your mobile’s camera.

Search for “coffee” and a bunch of markers appear on the view, showing you where the nearest coffee shops are.

As you move the phone around, the markers follow the approximate location of the places they are showing you.

That’s assuming you want to search ‘Google Local’, but that’s not the only option. Location data is provided through “layars”, and there are layars available for location-tagged Wikipedia articles, Flickr photos, brightkite users, and more.

The interesting thing talked about at openMIC was the Layar API which lets anyone create a new Layar with their own information.

So I decided to spend a quiet Friday afternoon in the office creating a Layar for around Hursley. 🙂

This means a phone with the Layar browser installed can browse and search for points of interest around the site.

It was really very easy, so I’ll quickly outline the steps involved.

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Pushing, pulling, or leaving the door open

Saturday, October 24th, 2009

This weekend is barcamplondon, so another chance for me to ramble incoherently about a technical topic of my choice. 🙂

My presentation started as a bit of a cop-out. I was ill last week and weekend when I was planning to prepare a new presentation, so I decided to give the same talk I did at Over The Air last month and hope that I didn’t get any of the same attendees.

But then I started tweaking it to suit the different audience. Over The Air is an event for mobile developers, so my presentation was pretty much aimed at mobile devs, which wasn’t quite right for a general event like barcamplondon.

Then I started updating it to reflect the feedback I got, both on the day at Over The Air, and through comments and tweets since.

My talk at OTA was a technical “Introduction to MQTT” session.

My presentation for barcamplondon became a broader look at mobile apps that rely on data from the Internet, and the challenges and choices facing mobile app developers who write them.

And I think it’s better for it. I hope it didn’t come across as pimping MQTT. I still talked about MQTT, but this time it was to use it as an example of one of a broader set of choices:

The aim of the talk was to discuss the pros and cons of each approach.

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Mobile Widgets – the new hotness?

Wednesday, October 21st, 2009

Over The Air was a month ago now, so this post has been sat in draft for way too long. But I thought it was still worth quickly sharing something noticeable from the event.

By way of quick background for those who aren’t familiar with it, it is an event for mobile developers – a couple of days filled with talks and presentations on all things mobile.

And this year, the big thing seemed to be widgets. There were a lot of talks on widgets. So many, in fact that you could choose a session in every time slot that was about widgets.

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Push notifications for mobile apps

Wednesday, September 30th, 2009

Update (1 Feb 2011): I’ve shared some better sample code for Android

Last weekend, I went to Imperial College for Over The Air: a conference for mobile developers.

I gave a talk at the event on how to write a mobile application that uses push notifications. It was pretty well received, so I’d thought I’d share it here, too.

I’ve made some notes below to cover roughly what I said at the event. Any comments or questions (or corrections if you spot any!) are very welcome. 🙂

Update (24/10/2009): I revisited this presentation to address some of the feedback that I got on battery life implications of using MQTT.

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OAuth authentication from a mobile device

Monday, August 31st, 2009

I wrote a post a couple of weeks ago in which I whined about the difficulties in creating a good user experience for a mobile client that authenticates with an OAuth provider.

I was pleasantly surprised (and a little honoured!) to get a comment on the post from Chris Messina reminding me that the way to address the usability issue isn’t to revert back to using usernames and passwords, but for us to all work to improve the usability of OAuth.

Sufficiently inspired, I went back and had another go.

It’s still not quite there, but I think it’s better.

As Andy pointed out last time, not everyone has a Windows Mobile device to try my code on, so this time I tried recording a screen capture of it.

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(Another!) Mobile app to share where you are

Saturday, August 29th, 2009

Mobile location sharing is something that I keep coming back to: from finding where my phone is using GPS, Bluetooth, WiFi Access Points, GSM Cell Ids, using my own hand-rolled systems or newer services like Google Latitude, dopplr, OpenCellID and Brightkite.

There is something about the promise of location-based apps which I find very exciting.

This is my excuse, at any rate, for sharing my latest bit of tinkering. 🙂

The stuff that I’ve tried so far has been focused on long-term sharing – apps intended to run in the background on your phone all the time, sharing your location with a pre-arranged list of friends and family who have signed up to the same service.

I’m playing with an app which comes at this from the other angle: an app for specific occasions to share your location. Not something to run in the background all the time, but an app to use when you want to let someone know where you are – a specific person. This could be a friend or family member, or a colleague or client (perhaps someone who hasn’t signed up to any service that you have).

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Accessing authenticated Google App Engine services from a .NET CF client

Monday, August 24th, 2009

Google App Engine (GAE) gives you an easy way to build and host web applications for free.

For any address you specify in your GAE app, you can require users to be authenticated. For example, if you have this in your app.yaml:

- url: /authme
  script: myAuthenticatedService.py
  login: required

When a user goes to http://yourapp.appspot.com/authme in their browser, they get taken first to a google.com logon page and promtped for their google username and password.

Only if they authenticate correctly will Google pass them back to your page, and let them access your /authme page.

(This is kinda nice, because as a GAE app developer, you shouldn’t need to see the user’s password. Although, I guess most users won’t make a distinction between typing in their username and password into the google.com login page and into a login form on an appspot.com page.)

If you are writing browser-delivered apps, this is all fine and works as described. This is slightly trickier if you are writing a web service that you want to be accessed by a client app. I wanted to access a GAE web service from a mobile client – this is how I’m doing it.

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A Fire Eagle updater for Windows Mobile

Thursday, August 13th, 2009

I wrote a Fire Eagle web service at Open Hack London a few months ago – that gave a nice, mobile-friendly way to share your current location, as stored in Fire Eagle.

Last week, I finally got round to updating my Fire Eagle Guest Pass web service to use the newer OAuth 1.0a.

This got me thinking that I haven’t used it very much since writing it in May… because while it let me share where Fire Eagle thinks I am, I didn’t have an easy mobile-friendly way to tell Fire Eagle where I am in the first place! 🙂

So while I had “how to do OAuth” fresh in my mind, I thought I’d start writing a quick mobile Fire Eagle client.

I wrote it in C# for Windows Mobile. There are a few interesting points in the code that deserve their own blog posts, but first I wanted to quickly show what I’ve got working so far.

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