Sinisa Randic

Implementation of IEEE 802.15.4 transceiver on software defined radio platform

Measurement of error probability parameters in IEEE 802.15.4 transmission requires clear access to all stages of commercially available IEEE 802.15.4 transceivers. Since these transceivers are realized as monolithic chips, with limited access to certain transceiver stages, we created an IEEE 802.15.4 transceiver on a Software Defined Radio (SDR) platform with clear access to all transceiver stages. Using the realized transceiver, we were able to create a system for measurement of error probability parameters in IEEE 802.15.4 transmission.

A wireless ECG sensor node based on Huffman data encoder

The paper presents design and implementation of a wireless sensor node suitable for medical applications. As physiological signals are highly redundant, the data compression algorithms (Huffmans coding) are used to save energy and improve the node performance. Design is based on the ARM Cortex M1 processor and implemented in FPGA.

Protothreads concept in embedded systems

The problem of concurrency in embedded systems, as well as the implementation of the protothreads are shown in this paper. Having limited system resources, especially small amount of memory, the concept of threads presented with modern operating systems is not applicable with embedded systems. Because of that, the protothreads were developed, very light threads that share single stack. They are implemented as separate C libraries or as an upgrade of existing operating system for embedded systems. As a practical implementation, the system with two protothreads that concurrently access the resources of microcontroller was developed. It is shown that the running time in case of using protothreads is greater than without them, which can be explained by lack of process scheduler.

TEDS specification for IEEE 1451.0 smart Transducer

IEEE 1451.0 standard enables independence of transducer to some degree in their functionality. TEDS represents electronic form of documents for storing all necessary data on smart transducers needed for independently executing action on the transducer. In this paper, realization of TEDS was presented on the mbed platform which was based on 32-bit ARM Cortex M3microcontroller. In paper, elements used for making TEDS structure and methods for read data from stored TEDS were described.

Realization of Web GIS platform using open source technologies

Data which beside their own information contains support in the form of geographic information systems have much greater usability. Location of some object can be useful in a large number of uses of that information. This paper described open source platform as a Web application that provides an identification and permanent recording of desired location. Geographical support is provided through the Google Maps geographic information system. This paper describes the used platforms and the complete functionality of the created Web application.

Android system for identification of objects based on QR code

This paper shows an Android-based system for identification of objects based on reading of QR codes. The system is developed to facilitate identification of various items that exist in already created inventory. The designed system is composed of a database, Web service for intermediary access to the database via Web, and the client Android application, that can be run on mobile phones or tablet computers. It is shown how this system can be used for cataloguing the computer equipment, but the usage of the system is not limited solely to this.

Concept of read data method according to IEEE 1451.0 standard using CC430F5137 microcontroller

Sensor devices are characterized by many constraints due to the nature of their use in many different environments. One of the main challenges in the development of autonomous sensing devices is the optimization of energy consumption. Therefore it is desirable to use low power microcontrollers for developing devices if it is possible also to satisfy other requirements. In addition, new trends in today technology require some intelligence of measuring devices in order to make the transducer more independent from human factors and to establish access to devices and their communication in much easier way. For this purpose standard IEEE 1451.0 was introduced, that defines common rules for smart transducers, regardless of the used equipment. This paper presents an example of data transmission in case of system based on low-power microcontroller CC430F5137 according to the smart transducer concept.

Hardware-software platform for object identification in IEEE 802.15.4 wireless networks

In this paper is presented the system for identification of objects in wireless sensor networks. Hardware of the system is consisted of sensor plate based on technology of capacitive detection of finger touch, wireless transceiver that sends its identification number when finger touch is detected, and server part which stores and processes data. Software of the system is composed of PC application that monitors nodes activities, identifies them, and performs certain statistical calculations.

Metadata analysis tool for IEEE 802.15.4 wireless networks

Wireless sensor networks are sensor networks responsible for the monitoring of physical phenomena. Energy efficiency is key aspect of the development for these networks, which can be significantly affected by planned distribution of sensors. Proposed metadata analysis tool in IEEE 802.15.4 networks can serve to collect the parameters of propagation of radio signals in certain areas, for planning the layout of sensors in space. This tool can also be used for the final correction of the sensors position in the deployed networks.

Test-Driven Development (TDD) in development of measure application and transducers services

Transducer services API provides the interface between the measure application and function defined by standrad IEEE 1451.0. This paper presents use Test-Driven Development (TDD) in implementation of methods of transducer services and Web application that access this services over the network. Characteristics of TDD and its benefits were presented and way of realization for one method was shown using Java and JUnit framework for run tests.