Writing MIDlets, Poking around, and GPS

It’s easy to write a simple app that runs on the Blackberry. This tutorial had us building code within the hour (starting from a java-free MacOS X machine). Getting it to load OTA was a little bit of a trial since the JAD file generated by Ant wasn’t quite up to snuff, but with a little bit of manual jiggery it loaded nicely. For BlackBerry-specific questions, the BlackBerry Developer KnowledgeBase looks to have a wealth of useful information for curious minds.

So can we use these tools to take advantage of the nifty features of the Blackberry — say, GPS? I think we can. There’s a blackberry.com knowldegebase article that hits some of the details. Then there’s JSR 179, Location API for J2ME, which promises to be the APIs implemented.

Finally, what can we learn from within the BlackBerry UI? There’s a suprising amount of interesting technical detail lurking in Settings->Options->Advanced Options.

Applications allows you to see all the application bundles loaded on the system — including, apparently, the Java classes they include! For example, highlighting “BlackBerry 4.2 Core Applications” and choosing Menu->Modules tells me that among others, it implements net_rim_app_manager_console 4.2.1.772.

GPS has a “Refresh GPS” menu choice, which cogitated for a while and told me I was at N 37° 47.1981′ W 122° 23.9948′ with an accuracy of 15.5m, according to 5 satellites. Most interesting, especially considering I declined to pay for the value-add GPS option from my carrier.