my2cents

29. July, 2007

SunSPOT will now exit

Filed under: Sun SPOT — frightanic @ 00:18

This blog now resides at http://www.frightanic.com/. It will be discontinued here…

I just discovered another mysterious error while working with SunSPOT.

For whatever reason I was no longer able to deploy an application via the base station to a free-range SPOT using the -DremoteId= switch. The log said among other things:

“Device reported:  Verification of command failed: Signature verification failed”

But it also said that I should try to run “ant settime” on both the base station and the free-range SPOT (directly connected via USB). I did as instructed, but the problem remained.

In the end I disconnected the base station, hooked up the free-range SPOT directly to the USB cord, and deployed my app without the -DremoteId= switch. That did the trick. After that I was able to deploy to a remote SPOT again.

26. June, 2007

Sunspotting at Jazoon

Filed under: Jazoon,Sun SPOT — frightanic @ 13:12

Sun SPOTs are incredibly cool sensor devices produced by, well, Sun Microsystems. They seem to have a real momentum right now.

At Jazoon in Zurich Sun’s Simon Ritter gave a top presentation about the SPOTs in general an fed us with some background info. Since I’m working on my own SPOT application it didn’t come as a surprise that much of it wasn’t new to me. Nonetheless, I learned that the Sun Squawk J2ME implementation was started as a totally independent project and that it should be easily portable to different mobile devices as its native layer is very thin. Also, I knew it but wasn’t fully aware that I can have several applications running on one and the same SPOT in parallel. The fact that a SPOT contains several boards that serve separate purposes underline that they were built with extensibility in mind. Simon demonstrated how to control a Looking Glass user interface with a P5 Data Glove. It wasn’t quite like what you might know from the “Minority Report” movie, yet.
What I don’t get though, is why Sun stresses that SPOTs can (and should) be used for real-world applications. Yet, all they ever present and demonstrate are toy-related “fun products”. Good for nerds, but not so good for management making decisions.

Ergon had a dual-player Arkanoid application with the two bars controlled by Sun SPOTs tilted left/right. It’s fun to play, but takes some time to get accustomed to the responsiveness of the sensor application. I want to build that, too! It shouldn’t take too long to turn a regular mouse-controlled Arkanoid implementation into a SPOT-controlled toy.

16. June, 2007

No sun spot basestation found

Filed under: Sun SPOT — frightanic @ 23:59

While deploying an application to a remote SunSPOT over the base station I get a “No sun spot basestation found” error every now and then. In the Sun SPOT forum are a few hints about that “problem”, but none really helped in my case. I’m currently developing on a Windows 2000 machine (once the new Sun SPOT beta release is installed I’ll switch to my MacBook).

Usually the base station is found automatically and you shouldn’t have to set the port explicitly. However, there are two parameters which allow you to point the “find spots” application into the right direction: sunport=COMn and port=COMn as explained in chapter 4 of the Developer’s Guide. So, whenever the base station apparently cannot be found I simply activate port=COM3 in my .sunspot.properties. That does the trick usually. Of course, I disable the parameter afterwards.

If that doesn’t help I go to my Windows Device Manager, open up the COM & LPT item and reinstall the Sun SPOT entry. Sometimes I need to restart my PC after that procedure.

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