Building real-time embedded applications on QduinoMC: a web-connected 3D printer case study

Single Board Computers (SBCs) are now emerging with multiple cores, ADCs, GPIOs, PWM channels, integrated graphics, and several serial bus interfaces. The low power consumption, small form factor and I/O interface capabilities of SBCs with sensors and actuators makes them ideal in embedded and real-time applications. However, most SBCs run non-realtime operating systems based on Linux and Windows, and do not provide a user-friendly API for application development. This paper presents QduinoMC, a multicore extension to the popular Arduino programming environment, which runs on the Quest real-time operating system. QduinoMC is an extension of our earlier single-core, real-time, multithreaded Qduino API. We show the utility of QduinoMC by applying it to a specific application: a web-connected 3D printer. This differs from existing 3D printers, which run relatively simple firmware and lack operating system support to spool multiple jobs, or interoperate with other devices (e.g., in a print farm). We show how QduinoMC empowers devices with the capabilities to run new services without impacting their timing guarantees. While it is possible to modify existing operating systems to provide suitable timing guarantees, the effort to do so is cumbersome and does not provide the ease of programming afforded by QduinoMC.http://www.cs.bu.edu/fac/richwest/papers/rtas_2017.pdfAccepted manuscrip

Methoden und Beschreibungssprachen zur Modellierung und Verifikation vonSchaltungen und Systemen: MBMV 2015 - Tagungsband, Chemnitz, 03. - 04. März 2015

Der Workshop Methoden und Beschreibungssprachen zur Modellierung und Verifikation von Schaltungen und Systemen (MBMV 2015) findet nun schon zum 18. mal statt. Ausrichter sind in diesem Jahr die Professur Schaltkreis- und Systementwurf der Technischen Universität Chemnitz und das Steinbeis-Forschungszentrum Systementwurf und Test. Der Workshop hat es sich zum Ziel gesetzt, neueste Trends, Ergebnisse und aktuelle Probleme auf dem Gebiet der Methoden zur Modellierung und Verifikation sowie der Beschreibungssprachen digitaler, analoger und Mixed-Signal-Schaltungen zu diskutieren. Er soll somit ein Forum zum Ideenaustausch sein. Weiterhin bietet der Workshop eine Plattform für den Austausch zwischen Forschung und Industrie sowie zur Pflege bestehender und zur Knüpfung neuer Kontakte. Jungen Wissenschaftlern erlaubt er, ihre Ideen und Ansätze einem breiten Publikum aus Wissenschaft und Wirtschaft zu präsentieren und im Rahmen der Veranstaltung auch fundiert zu diskutieren. Sein langjähriges Bestehen hat ihn zu einer festen Größe in vielen Veranstaltungskalendern gemacht. Traditionell sind auch die Treffen der ITGFachgruppen an den Workshop angegliedert. In diesem Jahr nutzen zwei im Rahmen der InnoProfile-Transfer-Initiative durch das Bundesministerium für Bildung und Forschung geförderte Projekte den Workshop, um in zwei eigenen Tracks ihre Forschungsergebnisse einem breiten Publikum zu präsentieren. Vertreter der Projekte Generische Plattform für Systemzuverlässigkeit und Verifikation (GPZV) und GINKO - Generische Infrastruktur zur nahtlosen energetischen Kopplung von Elektrofahrzeugen stellen Teile ihrer gegenwärtigen Arbeiten vor. Dies bereichert denWorkshop durch zusätzliche Themenschwerpunkte und bietet eine wertvolle Ergänzung zu den Beiträgen der Autoren. [... aus dem Vorwort

Car-Park Management using Wireless Sensor Networks

A complete wireless sensor network solution for car-park management is presented in this paper. The system architecture and design are first detailed, followed by a description of the current working implementation, which is based on our DSYS25z sensing nodes. Results of a series of real experimental tests regarding connectivity, sensing and network performance are then discussed. The analysis of link characteristics in the car park scenario shows unexpected reliability patterns which have a strong influence on MAC and routing protocol design. Two unexpected link reliability patterns are identified and documented. First, the presence of the objects (cars) being sensed can cause significant interference and degradation in communication performance. Second, link quality has a high temporal correlation but a low spatial correlation. From these observations we conclude that a) the construction and maintenance of a fixed topology is not useful and b) spatial rather than temporal message replicates can improve transport reliability

Application framework for wireless sensor networks [thesis]

Wireless Sensor Networks (WSNs) are based on innovative technologies that had revolutionized the methods in which we interact with the environment; i.e., through sensing the physical (e.g., fire motion, contact) and chemical (e.g., molecular concentration) properties of the natural surroundings. The hardware in which utilized by WSNs is rapidly evolving into sophisticated platforms that seamlessly integrate with different vendors and protocols (plug-n-play). In this thesis, we propose a WSN framework which provides assistance with monitoring environmental conditions; we focus on three main applications which include: a. Air-quality monitoring, b. Gas-leak detection, and c. Fire sensing. The framework involves four specifications: 1. Over the air programming (OTAP), 2. Network interconnections, 3. Sensors manageability, and 4. Alarm signaling. Their aim is to enhance the internetwork relations between the WSNs and the outside-world (i.e., main users, clients, or audience); by creating a medium in which devices efficiently communicate, independent of location or infrastructure (e.g., Internet), in order to exchange data among networked-objects and their users. Therefore, we propose a WSN-over-IP architecture which provides several renowned services of the Internet; the major functionalities include: live-data streaming (real-time), e-mailing, cloud storage (external servers), and network technologies (e.g., LAN or WLAN). WSNs themselves operate independently of the Internet; i.e., their operation involve unique protocols and specific hardware requirements which are incompatible with common network platforms (e.g., within home network infrastructure). Hybrid technologies are those which support multiple data-communication protocols within a single device; their main capabilities involve seamless integration and interoperability of different hardware vendors. We propose an overall architecture based on hybrid communication technology in which data is transmitted using three types of protocols: 802.11 (Wi-Fi), 802.15.4 and Digimesh (WSN)

An occam Style Communications System for UNIX Networks

This document describes the design of a communications system which provides occam style communications primitives under a Unix environment, using TCP/IP protocols, and any number of other protocols deemed suitable as underlying transport layers. The system will integrate with a low overhead scheduler/kernel without incurring significant costs to the execution of processes within the run time environment. A survey of relevant occam and occam3 features and related research is followed by a look at the Unix and TCP/IP facilities which determine our working constraints, and a description of the T9000 transputer's Virtual Channel Processor, which was instrumental in our formulation. Drawing from the information presented here, a design for the communications system is subsequently proposed. Finally, a preliminary investigation of methods for lightweight access control to shared resources in an environment which does not provide support for critical sections, semaphores, or busy waiting, is made. This is presented with relevance to mutual exclusion problems which arise within the proposed design. Future directions for the evolution of this project are discussed in conclusion

Adaptive voting computer system

A computer system is reported that uses adaptive voting to tolerate failures and operates in a fail-operational, fail-safe manner. Each of four computers is individually connected to one of four external input/output (I/O) busses which interface with external subsystems. Each computer is connected to receive input data and commands from the other three computers and to furnish output data commands to the other three computers. An adaptive control apparatus including a voter-comparator-switch (VCS) is provided for each computer to receive signals from each of the computers and permits adaptive voting among the computers to permit the fail-operational, fail-safe operation

Dependence-Based Source Level Tracing and Replay for Networked Embedded Systems

Error detection and diagnosis for networked embedded systems remain challenging and tedious due to issues such as a large number of computing entities, hardware resource constraints, and non-deterministic behaviors. The run-time checking is often necessitated by the fact that the static verification fails whenever there exist conditions unknown prior to execution. Complexities in hardware, software and even the operating environments can also defeat the static analysis and simulations. Record-and-replay has long been proposed for distributed systems error diagnosis. Under this method, assertions are inserted in the target program for run-time error detection. At run-time, the violation of any asserted property triggers actions for reporting an error and saving an execution trace for error replay. This dissertation takes wireless sensor networks, a special but representative type of networked embedded systems, as an example to propose a dependence-based source-level tracing-and-replay methodology for detecting and reproducing errors. This work makes three main contributions towards making error detection and replay automatic. First, SensorC, a domain-specific language for wireless sensor networks, is proposed to specify properties at a high level. This property specification approach can be not only used in our record-replay methodology but also integrated with other verification analysis approaches, such as model checking. Second, a greedy heuristic method is developed to decompose global properties into a set of local ones with the goal of minimizing the communication traffic for state information exchanges. Each local property is checked by a certain sensor node. Third, a dependence-based multi-level method for memory-efficient tracing and replay is proposed. In the interest of portability across different hardware platforms, this method is implemented as a source-level tracing and replaying tool. To test our methodology, we have built different wireless sensor networks by using TelosB motes and Zolertia Z1 motes separately. The experiments\u27 results show that our work has made it possible to instrument several test programs on wireless sensor networks under the stringent program memory constraint, reduce the data transferring required for error detection, and find and diagnose realistic errors

Intrusion detection system for wireless sensor network

A Wireless Sensor Network (WSN) is a group of sensor nodes, they monitor a certain environmental information (sound, temperature, motion, pressure, light, etc.), and transmit the information to the base station. Its important to protect the data while information transmitted into the wireless environment. Data can be protected by using cryptographic scheme. a number of attacks can be possible on WSN because of its broadcasting nature, resource restrictions, and remote area of deployment. cryptograpic security can secure network from outside attacks, but fails to protect from inside attack. so we need a second line of defence like Intrusion Detection System.This goal is achieved. PIR motion sensor transmits a signal to base station and the base station trigger an alert message whenever an intruder found into the room. Temperature sensor sends a signal whenever the temperature of room is cross a certain threshold. And light sensor sends a signal whenever intensity of light is cross certain threshold. The attacker node is used to attack on nodes. If IDS found the malicious activity which is done by attacker node, it generates an alert message with the victim nodes information. So we can change the nodes information. As base station is connected to the computer so WSN nodes can be controlled by computer

Flexible HW-SW design and analysis of an MMT-based MANET system on FPGA

Recently there has been a rapid growth of research interests in Mobile Ad-hoc Networks (MANETs). Their infrastructureless and dynamic nature demands that new strategies be implemented on a robust wireless communication platform in order to provide efficient end-to-end communication. Many routing algorithms have been developed to serve this purpose. This thesis investigated Multi-Meshed Tree (MMT) algorithm, an integrated solution that combines routing, clustering and medium access control operations based on a common multi-meshed tree concept. It provides the robustness and redundancy inherent in mesh topologies and uses the tree branches to deliver packets. MMT is the first of its kind that enables a single algorithm to form multiple proactive routes within a cluster while supporting reactive routes between different clusters. Recent published research and simulations have shown its favorable features and results. To explore the MMT algorithm\u27s novel feature in real systems against simulation work, this work adopts Field Programmable Gate Arrays (FPGA) as the platform for wireless system implementations. Full hardware and various System-on-Chip Hardware-Software designs are developed and studied, providing a design practice that contributes to low-cost system development in the field of MANET by utilizing the evolving FPGA technology. The results show that the MMT-based systems functioned accurately and effectively; in all proposed test scenarios they demonstrated many of the features that a desired MANET routing algorithm should have: high transmission success rate, low latency, scalability, few queued packets and low overhead. The results give valuable insights into the MMT algorithm\u27s performance and facilitate its future improvements