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Sun SPOT (Sun Small Programmable Object Technology) was asensor node for awireless sensor network developed bySun Microsystems announced in 2007. The device used theIEEE 802.15.4 standard for its networking, and unlike other available sensor nodes, used theSquawkJava virtual machine.
After the acquisition of Sun Microsystems byOracle Corporation, the SunSPOT platform was supported but its forum was shut down in 2012.[1] A mirror of the old site is maintained for posterity.[2]
The completely assembled device fit in the palm of a hand.
Its first processor board included anARM architecture 32 bit CPU withARM920T core running at 180 MHz. It had 512 KB RAM and 4 MBflash memory. A 2.4 GHzIEEE 802.15.4 radio had an integrated antenna and aUSB interface was included.[3]
A sensor board included a three-axisaccelerometer (with 2G and 6G range settings), temperature sensor, light sensor, 8 tri-color LEDs, analog and digital inputs, two momentary switches, and 4 high current output pins.[3]
The unit used a 3.7V rechargeable 750 mAhlithium-ion battery, had a 30 uA deep sleep mode, and battery management provided by software.[3]
The device's use of Java device drivers is unusual since Java is generally hardware-independent. Sun SPOT uses a smallJava MESquawk which ran directly on the processor without anoperating system. Both the Squawk VM and the Sun SPOT code are open source.[4]Standard Java development environments such asNetBeans can be used to create SunSPOT applications.The management and deployment of application are handled by ant scripts, which can be called from a development environment, command line, or the tool provided with the SPOT SDK, "solarium".[citation needed]
The nodes communicate using theIEEE 802.15.4 standard including the base-station approach to sensor networking. Protocols such asZigbee can be built on 802.15.4.Sun Labs reported implementations ofRSA andelliptic curve cryptography (ECC) optimized for small embedded devices.
Sun Microsystems Laboratories started research onsensor networks around 2004. After some initial experience using "Motes" fromCrossbow Technology, a project began under Roger Meike to design an integrated hardware and software system.[5]Sun sponsored a project at theArt Center College of Design called Autonomous Light Air Vessels in 2005.[6]The first limited-production run of Sun SPOT development kits were released April 2, 2007, after months of delays. This introduction kit included two Sun SPOT demo sensor boards, a Sun SPOT base station, the software development tools, and a USB cable. The software was compatible with Windows XP, Mac OS X 10.4, and common Linux distributions. Some demonstration code was provided.[citation needed]
A developer from Sun gave a demonstration in September 2007.[3]After investigating commercial use, Sun moved to focus on educational users.The entire project, hardware, operating environment, Java virtual machine, drivers and applications, was available as open source in January 2008.[4][7][8]
Oracle Corporation acquired Sun Microsystems in 2010 and continued Sun SPOT development, through release 8 of the hardware (with Sun-Oracle logo) by March 2011.[9]The 2011 version included larger memories and a faster processor, but with fewer inputs.[10]
In 2012 the forum said it would be "down for maintenance" until "mid-June".[1] A new forum was started on the Oracle Technology Network on May 7, 2013.[11] David G. Simmons, one of the SunSPOT developers for Sun Microsystems, maintained a blog through the end of 2010.[12]He opened an alternative developers forum in July 2013 not connected to Oracle.[13]
When the project was shut down, the lead hardware engineer for the SunSPOT project, Bob Alkire, archived the hardware design on his personal website.[14]