Smart sensors for measuring temperature and pressure have been developed as part of the Advanced Ground Systems Maintenance (AGSM) project. The sensors have flash memory for storing firmware, calibration data, and configuration information. In anticipation of the sensors being installed at multiple locations (possibly numbering in the hundreds) around the Kennedy Space Center, a method was devised to update the firmware of many sensors quickly and easily.

This method involves using the Universal File Transfer Protocol (UFTP) to send files to many smart sensor devices over the network. UFTP uses multicast network packets that allow multiple smart sensors on the network to receive the file simultaneously. The UFTP software has been adapted to run in the limited resources available in the embedded processing environment of the smart sensors. The UFTP software has also been augmented to specify the version number and type (program, data, etc.) of the file being transferred so that the smart sensors can determine if they already have the specified version.

The components used for the innovation are one or more AGSM smart sensors running the software that includes the UFTP functionality, a server used to distribute firmware updates to the smart sensors, and a UFTP command line tool on the server to send the firmware updates to the smart sensors using UFTP. The smart sensor firmware update is initiated by running the UFTP command line tool. A message is broadcast on the net notifying the sensors that a file is available. The sensors generate a response indicating whether or not they want to receive the file. The UFTP command line tool then sends the firmware file in blocks to all the sensors simultaneously using the UDP multicast packets. Sensors that miss a block, or receive a corrupted block, can request that the blocks be resent. The process continues until all the blocks in the firmware file have been sent and all sensors acknowledge that they have received the complete file. The UFTP command line tool displays the overall results of the file transfer and timing information on the duration of the transfer. The use of acknowledgements and resends of the file blocks ensures the integrity of files received by the smart sensors.

This work was done by Charles Chapman of QinetiQ North America, Inc. for Kennedy Space Center. For more information, contact the Kennedy Space Center Technology Transfer Office at 321-867-7171. KSC-13830

Software Tech Briefs Magazine

This article first appeared in the September, 2014 issue of Software Tech Briefs Magazine.

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