Detection of Musical Notes Using a Polyphonic Pitch Tracking Embedded System

Detection of polyphonic notes using embedded systems is a field that has not been explored. This article describes a polyphonic tracking embedded system that can detect on real time single and multiple musical notes, as well as their time duration. The solution was designed on an embedded system with a Cortex M-7 core as processor. This was achieved with an algorithm using fast Fourier transform iterating on two buffers in coordination with the direct memory access peripheral. The proposed embedded system was able to detect multiple musical notes on real time. Future works could use the results of this design and export them to a real music editing format.ITESO, A. C

Embodied Interactions with E-Textiles and the Internet of Sounds for Performing Arts

This paper presents initial steps towards the design of an embedded system for body-centric sonic performance. The proposed prototyping system allows performers to manipulate sounds through gestural interactions captured by textile wearable sensors. The e-textile sensor data control, in real-time, audio synthesis algorithms working with content from Audio Commons, a novel web-based ecosystem for repurposing crowd-sourced audio. The system enables creative embodied music interactions by combining seamless physical e-textiles with web-based digital audio technologies

A Three-Tier Approach for Composition of Real-Time Embedded Software Stacks

CORE A.International audienceMany component models and frameworks have been proposed to abstract and capture concerns from Real-Time and Embedded application domains, based on high-level component-based approaches. However, these approaches tend to propose their own fixed-set abstractions and ad-hoc runtime platforms, whereas the current trend emphasizes more flexible solutions, as embedded systems must constantly integrate new functionalities, while preserving performance. In this paper, we present a two-fold contribution addressing this statement. First, we propose to express these concerns in a decoupled way from the commonly accepted structural abstractions inherent to CBSE, and provide a framework to implement them in open and extensible runtime containers. Second, we propose a three-tier approach to composition where application, containers and the underlying operating system are designed using components. Supporting a homogeneous design space allows applying optimization techniques at these three abstraction layers showing that our approach does not impact on performance. In this paper, we focus our evaluation on concerns specific to the field of real-time audio and music applications

Uber-in-light: Unobtrusive visible light communication leveraging complementary color channel

Abstract: Recently, Visible Light Communication (VLC) over a screen-camera channel has drawn considerable attention to unobtrusive design. It overcomes the distractive nature of traditional coded image approaches (e.g., barcodes). Previous unobtrusive methods fall into two categories: (1) utilizing alpha channel, a well known concept in computer graphics, to encode bits into the pixel translucency change with off-the-shelf smart devices; and (2) leveraging the spatial-temporal flicker-fusion property of human vision system with the fast frame rate of modern displays. However, these approaches heavily rely on high-end devices to achieve both unobtrusive and high accuracy screen-camera-based data communication without affecting video-viewing experience. Unlike previous approaches, we propose Uber-in-light, a novel unobtrusive and accurate VLC system, that enables real-time screen-camera communication, applicable to any screen and camera. The proposed system encodes the data as complementary intensity changes over Red, Green, and Blue (RGB) color channels that could be successfully decoded by camera while leaving the human visual perception unaffected. We design a MFSK modulation scheme with dedicated frame synchronization signal embedded in an orthogonal color channel to achieve high throughput. Furthermore, together with the complementary color intensity, an enhanced MUSIC-based demodulation scheme is developed to ensure highly accurate data transmission. Our user experience experiments confirmed the effectiveness of delivering unobtrusive data across different types of video content and resolutions. Extensive real-time performance evaluations are conducted using our prototype implementation to demonstrate the efficiency and reliability of the proposed system under diverse wireless environments

A voice operated musical instrument.

Many mathematical formulas and algorithms exist to identify pitches formed by human voices, and this has continued to be popular in the fields of music and signal pro-cessing. Other systems and research perform real time pitch identification implemented by using PCs with system clocks faster than 400MHz. This thesis explores developing an embedded RPTI system using the average magnitude difference function (AMDF), which will also use MIDI commands to control a synthesizer to track the pitch in near real time. The AMDF algorithm was simulated and its performance analyzed in MATLAB with pre-recorded sound files from a PC. Errors inherent to the AMDF and the hardware constraints led to noticeable pitch errors. The MATLAB code was optimized and its performance verified for the Motorola 68000 assembly language. This stage of development led to realization that the original design would have to change for the processing time required for the AMDF implementation. Hardware was constructed to support an 8MHz Motorola 68000, analog input, and MIDI communications. The various modules were constructed using Vectorbord© prototyping board with soldered tracks, wires and sockets. Modules were tested individually and as a whole unit. A design flaw was noticed with the final design, which caused the unit to fail during program execution while operating in a stand-alone mode. This design is a proof of concept for a product that can be improved upon with newer components, more advanced algorithms and hardware construction, and a more aesthetically pleasing package. Ultimately, hardware limitations imposed by the available equipment in addition to a hidden design flaw contributed to the failure of this stand-alone prototype

Modelling Embedded Systems with AADL: A Practical Study

In today’s world, embedded systems can be seen everywhere around us. These systems range from consumer electronics such as mobile phones, cameras and portable music players to sophisticated devices such as planes and satellite systems. In either form embedded systems are designed to perform specific tasks with constraints on their qualities and available resources. These constraints can either be soft or hard depending on the nature of the system: a satellite system, for example, has hard safety constraints. Some of the major constraints for embedded systems are high reliability, performance, safety and dependability, small memory size, low power and low processing capabilities. Designing systems with such constraints is a challenge. Developing system architectures during system development has gained importance as it helps in analyzing the system before its implementation. A system architecture is a formal description of a system that describes its building blocks, their properties and the interactions among them. System architectures can be used to analyze various properties of a system such as memory consumption and system safety. For embedded systems, this is of extreme importance since a well described system architecture allows us to predict whether any of the previously mentioned constraints can be met, without requiring the construction of an often expensive prototype implementation. Description of system architectures can be achieved using the formal notations offered by Architecture Description Languages (ADLs). Such ADLs often also provide tool support for the modelling and analysis of the system architecture. Many ADLs for embedded systems are available in both academic and industrial communities, such as Rapide, MetaH, AADL and Wright. Among the available ADLs, the best known and most actively used language is the Architecture Analysis and Design Language (AADL). Standardized by the Society of Automotive Engineers, AADL was originally developed for modelling and analysis of systems in the domain of avionics. However, because of its rich modelling and analysis capabilities, it is widely used for embedded systems in other domains as well. AADL provides a modelling formalism accompanied by a toolset to support modelling activities and system analyses. AADL models can be used to perform various analyses such as flow latency, resource consumption, real-time schedulability, security and safety analysis. Because of its history in the avionics domain, AADL does not address each and every modelling and analysis requirement of other embedded domains. However, during its design, it was foreseen that use of AADL in other domains could require additional modelling concepts and analyses. To meet potential needs AADL was designed as an extensible ADL. This chapter is intended to provide insight into the design needs of embedded systems and the formalisms available to address those needs.status: publishe

Context-aware adaptation in DySCAS

DySCAS is a dynamically self-configuring middleware for automotive control systems. The addition of autonomic, context-aware dynamic configuration to automotive control systems brings a potential for a wide range of benefits in terms of robustness, flexibility, upgrading etc. However, the automotive systems represent a particularly challenging domain for the deployment of autonomics concepts, having a combination of real-time performance constraints, severe resource limitations, safety-critical aspects and cost pressures. For these reasons current systems are statically configured. This paper describes the dynamic run-time configuration aspects of DySCAS and focuses on the extent to which context-aware adaptation has been achieved in DySCAS, and the ways in which the various design and implementation challenges are met

Designing relational pedagogies with jam2jamXO

This paper examines the affordances of the philosophy and practice of open source and the application of it in developing music education software. In particular I will examine the parallels inherent in the ‘openness’ of pragmatist philosophy in education (Dewey 1916, 1989) such as group or collaborative learning, discovery learning (Bruner 1966) and learning through creative activity with computers (Papert 1980, 1994). Primarily I am interested in ‘relational pedagogies’ (Ruthmann and Dillon In Press) which is in a real sense about the ethics of the transaction between student and teacher in an ecology where technology plays a more significant role. In these contexts relational pedagogies refers to how the music teacher manages their relationships with students and evaluates the affordances of open source technology in that process. It is concerned directly with how the relationship between student and teacher is affected by the technological tools, as is the capacity for music making and learning. In particular technologies that have agency present the opportunity for a partnership between user and technology that enhances the capacity for expressive music making, productive social interaction and learning. In this instance technologies with agency are defined as ones that enhance the capacity to be expressive and perform tasks with virtuosity and complexity where the technology translates simple commands and gestures into complex outcomes. The technology enacts a partnership with the user that becomes both a cognitive and performative amplifier. Specifically we have used this term to describe interactions with generative technologies that use procedural invention as a creative technique to produce music and visual media

Latency Performance for Real-Time Audio on BeagleBone Black

In this paper we present a set of tests aimed at evaluating the responsiveness of a BeagleBone Black board in real-time interactive audio applications. The default Angstrom Linux distribution was tested without modifying the underlying kernel. Latency measurements and audio quality were compared across the combination of different audio interfaces and audio synthesis models. Data analysis shows that the board is generally characterised by a remarkably high responsiveness; most of the tested configurations are affected by less than 7ms of latency and under-run activity proved to be contained using the correct optimisation techniques

Tangible user interfaces : past, present and future directions

In the last two decades, Tangible User Interfaces (TUIs) have emerged as a new interface type that interlinks the digital and physical worlds. Drawing upon users' knowledge and skills of interaction with the real non-digital world, TUIs show a potential to enhance the way in which people interact with and leverage digital information. However, TUI research is still in its infancy and extensive research is required in or- der to fully understand the implications of tangible user interfaces, to develop technologies that further bridge the digital and the physical, and to guide TUI design with empirical knowledge. This paper examines the existing body of work on Tangible User In- terfaces. We start by sketching the history of tangible user interfaces, examining the intellectual origins of this field. We then present TUIs in a broader context, survey application domains, and review frame- works and taxonomies. We also discuss conceptual foundations of TUIs including perspectives from cognitive sciences, phycology, and philoso- phy. Methods and technologies for designing, building, and evaluating TUIs are also addressed. Finally, we discuss the strengths and limita- tions of TUIs and chart directions for future research