Lucas Torri's Blog

January 2008 Archives

Sun SPOT more Open Source than ever

After releasing the Squawk VM as Open Source, Sun announced yesterday that has open sourced the SPOT libraries as well, under GPLv2. SPOTs are small, Java-based, wireless devices developed at Sun Labs. This libraries include the code responsible for wireless communication, sensors control and security at the devices. The news was published in the forum and can be seen the the java.net project website: https://spots.dev.java.net/

Roger Meike, research director at Sun Labs, said: "We created this technology to inspire students and educators to develop new, creative and useful applications". Also, he says that the decision of open sourcing the SPOT libs are based in the commitment to support the growing community of developers.

These are great news for we, SPOT lovers, and the Open Source community. Thanks!

NetBeans 6 T-shirt

September of last year I participated in a Contest at the netbeans.tv website, where the participants should share some photos or videos about the place where they live, work, etc. I created a entry about the city I live, Florianópolis. Unfortunately I didn't won the contest (the prize was a 1 GB Pen Drive and a Rich Client Programming Book), but at least I won a NetBeans T-shirt. Today I received a package with the T-shirt and it is great! The photos as usual aren't very good, but take a look:

The package from Sun

T-shirt front, that remember a metro map

T-shirt back, with NetBeans logo

RFID tags to tell a washer/dryer how to wash clothes

This is great! Technology to help us with domestic tasks. Designer Samgmin Bae has designed the clothTag, an RFID tag that could communicate with RFID enabled washers, dryers, irons, presses, and dry cleaning equipment, adjusting all settings automatically. You will just need to load your clothes, add detergent and shut the lid.

It looks even prettier than the normal labels:

Like the designer says "I find it surprising 70% of people don’t read the care labels and when they do, it’s usually too late". I personally don't know anything about cloth labels, so this would be a great help to avoiding me to destroy clothes =P

Notice found at Make Blog

Adding a Humidity Sensor to Sun SPOT

Happy new year for everybody!

Last month I got a Sun SPOT from a friend that came back from US and I can say that the kit is very cool. Now, in my way to learn more about it I decided to add a Humidity Sensor to the board.

This was my first experience on extending the SPOT hardware so in the beginning I was a little petrified but the process showed to be very simple. I got a free sample Humidity Sensor from Sensirion . I didn't imagined it was so little.

After wiring up the sensor and adding the necessaries resistor and capacitor I powered it, but there was no way to know if it was working, so I started to implement the Sensor communication protocol using Java. The component has 4 connectors: VDD, for power supply; GND for ground; DATA , for bidirectional data transfer and for last SCK that is clock signal for controlling the transfer. I decided to use +3V and GND available in the SPOT board and D0 e D1 for SCK and DATA respectively. The result program you can download here. This program is responsible for achieving the Sensor data and convert it using the formulas given by Sensirion.

Then, I connect the wires of the Sensor circuit to the SPOT board, programmed the software and surprisingly I got the expected results, showing that current temperature is near 29 Celsius degrees and the relative humidity is in 79%. SOrh and SOt are the values got directly from the Sensor.

All this got me less than 2 hours. Using the Sensor Data Sheet and SPOT Javadoc and documentation as reference I can say that this task was incredibly easy to do.

This work is licensed under a Creative Commons License.