Sun Spot

External Jars In Host Application SUNSPOTS

2008-11-17T02:26:00.000-08:00

If you want to include host apps in windows under Netbeans, adding it to classpath in properties is not enough, you actually need to go to the build.properties file and add the path there

example:

C:\Program Files\NetBeans 6.1\java2\modules\ext\AbsoluteLayout.jar:C:/jar/pccomm.jar:C:/jar/bluecove.jar

Note that the directory seperators should be "/" instead of "\".

SunSpots + Lejos

2008-11-13T16:18:00.000-08:00

Recently, I have been working on trying to get Lejos (Java For Lego) on Mac.
And I got no where. Lejos do not have mac universal install package so had to swith to windows.
It took me few about an hour to install lejos and eclipse. However eclipse did not do a great job setting Lejos up as an update. So I went back to the basic of uploading my program to NXT via bluetooth on terminal.

Lejos tutorial is good interms of explaining how to use the api's however they dont tell you anything about which libs you need to set up to get the bluetooth working or maybe I just missed
it.

First of you need to set you bluetooth with windows. You need to go to control panel and search for NXT bluetooth. NXT's bluetooth should be on and visible. After it is detected you need to choose the read pass from documentation box and type the passphrase which is 1234.
This should enable the bluetooth connection. Now you can upload your apps via bluetooth rather than USB.

But not yet there:

If you are writing a host application which communicates with the NXT via BlueTooth, there are few things that one has to pay attention to: first of all unlike a regular NXT app you should not use the classes.jar that comes with Lejos. The classes.jar should only be used for apps that runs on NXT. Second you need to add the bluecove.jar file which is in lejos 3rdparty folder.
If all goes well. Bluetooth should work

Lejos did a great job of abstracting the bluetooth stack from the user. All you need to do is to
NXTCommFactory class to create connections. The details are in the Documentation.

Reset Button Does not work.

2008-11-12T01:31:00.000-08:00

This issue usually arise when user sets one of the Threads with a higher priority. Interestingly SUN did not create a tool to flush the memory with out asking user to reset the spots by pressing the reset button.

I found a solution around this problem.

Here is how it goes:

1. Disconnect the Sun SPOT from the USB cable
2. Kill all the ant and java processes listening on the port
3. Hold the control button in for a few seconds until a double red flash indicates that the Sun SPOT has powered down (NB doing this *after* disconnecting).
4. Type this command at a command prompt:
ant -Dport=xxx upgrade
where xxx is the port name
5. Plug it in as soon as the ant script starts to complain that the port isn't available. *Don't* push the reset button: this isn't necessary and may confuse.

Adding external jars under Netbeans for sunspot settings

2008-11-05T00:52:00.000-08:00

Adding external jars in Netbeans under a project created for sonspots are a bit tricky.

Even if you are using a sunspot host application.

To add a jar file you need to do only do one thing if you are using "blue", which you should anyway.

You need to go to the properties.build file and add extra jar files there.

I am in this example adding restlet jar files.

user.classpath=/Applications/NetBeans.app/Contents/Resources/NetBeans/platform6/modules/ext/swing-layout-1.0.jar:/Applications/NetBeans.app/Contents/Resources/NetBeans/ide7/modules/ext/AbsoluteLayout.jar:/Users/evrenbingol/SPOTUI/lib/org.restlet.jar:/Users/evrenbingol/SPOTUI/lib/com.noelios.restlet.jar:/Users/evrenbingol/SPOTUI/lib/com.noelios.restlet.ext.servlet_2.4.jar

Last three jar files are external and the first one is netbeans set.

AODV specific

2008-10-19T17:02:00.000-07:00

aodv is not a link state algorithm which means that it would take a while to get the right hop counts since aodv needs to calculate the routes and hop counts on the fly

One way to cheat is to broadcast a message from each spot as your app initializes. This creates the missing routes in you aodv table. Which means that when you query the table entries later on you get the right results.

Sun Spot Deep Sleep AODV

2008-10-18T19:01:00.000-07:00

Stopping the network threads for deep sleep.

Since the release of the blue API, aodv classes provide methods for putting the treads on hold

You can get to the functions bye calling the routing manager instance.

Debugging Sun Spots

2008-09-26T00:39:00.001-07:00

The best way to debug, if you are not connected to your computer via USB, is to use the HTTP protocol and post the errors on line in your try catches.

Sun Spot Deep Sleep

2008-09-25T18:25:00.000-07:00

My Sun Spot is not going to sleep?

1) The most common reason for this is that people forget to turn for the mesh routing.

This does not allow the spots to go to deep sleep.(you can also set its policy in the code)

2) All running threads needs to be sleeping. If you have a thread listening for a radio connection this thread does not matter since it is a blocking I/O. As long as this thread wont receive messages from others spots, you are good to go.

3) If you have OTA server running then you need to set its policy. You can do this by creating a dummy connection. RadiogramConnection conn = (RadiogramConnection) Connector.open("radiogram://:42");

conn.setRadioPolicy(RadioPolicy.OFF);

4) To create different threads for each separate action might be a good programming practice, but it make things difficult. Trying to put the threads to sleep separately becomes a big problem.

So instead have one thread for everything.

Also if you are reading a radiogram than you need to disable blocking on radiogram's read() methods.

5) Also you can turn of the AODV by AODVManager.getInstance().stop();

6)After hours of debugging I finally understand that while there is an active radio connection the spots wont go to sleep. So right before you have to go to deep sleep you have to close() the connections and reopen it as the threads sleep() ends.