This week I had a day out of the office to go to Zurich to talk at this years IBM developerWorks Days. I had 2 sessions back to back in the mobile stream, the first an introduction to Android Development and the second on MQTT.

The slots were only 35mins long (well 45mins, but we had to leave 5 mins on each end to let people move round) so there was a limit to how much detail I could go into. With this in mind I decided the best way to give people a introduction to Android Development in that amount of time was to quickly walk through writing reasonably simple application. The application had to be at least somewhat practical, but also very simple so after a little bit of thinking about I settled on an app to download the latest image from the web comic XKCD. There are a number apps on Google Play that already do this (and a lot better) but it does show a little Activity GUI design. I got through about 95% of the app live on stage and only had to copy & paste the details for the onPostExecute method to clear the progress dialog and update the image in the last minute to get it to the point I could run it in the emulator.

Here are the slides for this session

And here is the Eclipse project for the Application I created live on stage:
http://www.hardill.me.uk/XKCD-demo-android-app.zip

The MQTT pitch was a little easier to set up, there is loads of great content on MQTT.org to use as a source and of course I remembered to include the section on the MQTT enabled mouse traps and twittering ferries from Andy Stanford-Clark.

Here are the slides for the MQTT session:

For the Demo I used the Javascript d3 topic tree viewer I blogged about last week and my Raspberry Pi running a Mosquitto broker and a little script to publish the core temperature, load and uptime values. The broker was also bridged to my home broker to show the feed from my weather centre and some other sensors.