Easy and Affordable Digital Signal Processing The aim of this book is to teach the basic principles of Digital Signal Processing (DSP) and to introduce it from a practical point of view using the bare minimum of mathematics. Only the basic level of discrete-time systems theory is given, sufficient to implement DSP applications in real time. The practical implementations are described in real time using the highly popular ESP32 DevKitC microcontroller development board. With the low cost and extremely popular ESP32 microcontroller, you should be able to design elementary DSP projects with sampling frequencies within the audio range. All programming is done using the popular Arduino IDE in conjunction with the C language compiler. After laying a solid foundation of DSP theory and pertinent discussions on the main DSP software tools on the market, the book presents the following audio-based sound and DSP projects: Using an I²S-based digital microphone to capture audio sound Using an I²S-based class-D audio amplifier and speaker Playing MP3 music stored on an SD card through an I²S-based amplifier and speaker Playing MP3 music files stored in ESP32 flash memory through an I²S-based amplifier and speaker Mono and stereo Internet radio with I²S-based amplifiers and speakers Text-to-speech output with an I²S-based amplifier and speaker Using the volume control in I²S-based amplifier and speaker systems A speaking event counter with an I²S-based amplifier and speaker An adjustable sinewave generator with I²S-based amplifier and speaker Using the Pmod I²S2 24-bit fast ADC/DAC module Digital low-pass and band-pass real-time FIR filter design with external and internal A/D and D/A conversion Digital low-pass and band-pass real-time IIR filter design with external and internal A/D and D/A conversion Fast Fourier Transforms (FFT)

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Du détecteur à la radio définie par logiciel La technologie des radiofréquences (RF) est l'un des domaines qui permet encore de mettre en pratique ses propres idées. D'innombrables variantes de circuits avec des objectifs particuliers laissent place à des expériences et des projets significatifs. Beaucoup de choses ne sont tout simplement pas disponibles dans le commerce. Des radios à détecteur de cristal sans source d'alimentation propre, de simples récepteurs à tube avec une touche de nostalgie, les premières tentatives de réception de Software Defined Radio, des récepteurs spéciaux pour radioamateur, tout cela peut être réalisé avec peu d'effort et comme une parfaite introduction à l'électronique RF. Pendant longtemps, la construction radio a été le premier pas vers l’électronique. Il existe cependant d’autres moyens, notamment via les ordinateurs, les microcontrôleurs et le numérique. Cependant, les racines analogiques de l’électronique sont souvent négligées. La technologie radio élémentaire et les expériences faciles à réaliser sont particulièrement adaptées comme domaine d'apprentissage de l'électronique, car vous pouvez ici commencer par les bases les plus simples. Mais le lien avec la technologie numérique moderne est également évident, par exemple lorsqu'il s'agit de méthodes de réglage modernes telles que PLL et DDS ou de radios DSP modernes. Ce livre vise à donner un aperçu et à présenter une collection de projets RF simples. L'auteur souhaite vous aider à développer vos propres idées, à concevoir vos propres récepteurs et à les tester.

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Program and build Arduino-based ham station utilities, tools, and instruments In addition to a detailed introduction to the exciting world of the Arduino microcontroller and its many variants, this book introduces you to the shields, modules, and components you can connect to the Arduino. Many of these components are discussed in detail and used in the projects included in this book to help you understand how these components can be incorporated into your own Arduino projects. Emphasis has been placed on designing and creating a wide range of amateur radio-related projects that can easily be built in just a few days. This book is written for ham radio operators and Arduino enthusiasts of all skill levels, and includes discussions about the tools, construction methods, and troubleshooting techniques used in creating amateur radio-related Arduino projects. This book teaches you how to create feature-rich Arduino-based projects, with the goal of helping you to advance beyond this book, and design and build your own ham radio Arduino projects. In addition, this book describes in detail the design, construction, programming, and operation of the following projects: CW Beacon and Foxhunt Keyer Mini Weather Station RF Probe with LED Bar Graph DTMF Tone Encoder DTMF Tone Decoder Waveform Generator Auto Power On/Off Bluetooth CW Keyer Station Power Monitor AC Current Monitor This book assumes a basic knowledge of electronics and circuit construction. Basic knowledge of how to program the Arduino using its IDE will also be beneficial.

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Secrets sonores et technologie Que serait la musique rock et pop d'aujourd'hui sans les guitares électriques et les basses ? Ces instruments donnent le ton depuis plus de soixante ans. Leur son sous-jacent est largement déterminé par leurs composants électriques. Mais comment fonctionnent-ils concrètement ? Presque personne n’est capable d’expliquer cela au vrai musicien sans formation technique. Ce livre répond à de nombreuses questions de manière simple et compréhensible. Pour le musicien intéressé (et les autres), ce livre dévoile, de manière simple et approfondie, ce qui était jusqu'à présent considéré comme des secrets de fabrication. L'examen explore les profondeurs de la guitare, y compris les micros et l'environnement électrique, afin que l'électronique de la guitare ne soit plus considérée comme hautement secrète. Avec quelques interventions habiles, de nombreux instruments peuvent être rendus plus polyvalents et mieux sonner – de la manière la plus rentable. L'auteur est un professionnel de l'électronique expérimenté et un musicien actif. Il a testé minutieusement tout ce qui est décrit ici, dans la pratique.

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La technologie des ondes courtes présente un attrait particulier : elle peut facilement couvrir de grandes distances. En faisant rebondir les signaux à ondes courtes sur les couches conductrices de l’ionosphère, ils peuvent être reçus au-delà de l’horizon et ainsi atteindre n’importe où sur Terre. Bien que la technologie évolue vers des fréquences de plus en plus élevées et que la radio soit généralement écoutée sur FM, DAB+, satellite ou Internet, les méthodes de transmission modernes nécessitent une infrastructure étendue et sont extrêmement vulnérables. En cas de panne de courant mondiale, rien n’est plus important que les ondes courtes. La radio amateur n'est pas seulement un passe-temps, c'est aussi un système radio d'urgence ! Le SDR-Shield d'Elektor (SKU 18515) est un récepteur polyvalent à ondes courtes jusqu'à 30 MHz. À l'aide d'un Arduino et du logiciel approprié, les stations de radio, les signaux Morse, les stations SSB et les signaux numériques peuvent être reçus. Dans ce livre, l'auteur à succès et radioamateur enthousiaste Burkhard Kainka décrit la pratique moderne de la radio définie par logiciel utilisant le Shield SDR d'Elektor. Il fournit non seulement une formation théorique, mais explique également de nombreux outils logiciels open source.

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All you need to know about good acoustics and sound systems in performance and worship spaces! Everyone knows that the ability to hear music in balance and to understand speech is essential in any space used for performance or worship. Unfortunately, in the early 21st century, we find that buildings with good acoustics are the exception rather than the rule. Much of the fault leading to this result can be traced to the widespread perception that acoustics is a black art. In fact, scientific acoustics as developed in the last century is a well-defined engineering practice that can lead to predictable excellent results. A basic, non-engineering understanding of acoustics will help building owners, theater managers, ministers and teachers of music, performers, and other professionals to achieve their goals of excellent acoustics in venues with which they work. Performers having a basic understanding of acoustics will be able to make the most of the acoustics of the venue in which they perform. This book helps those responsible for providing good acoustics in performance and worship spaces to understand the variables and choices entailed in proper acoustic design for performance and worship. Practicing acoustical consultants will find the book a useful reference as well. The level of presentation is comfortable and straightforward without being simplistic. If correct acoustical principles are incorporated into the design, renovation, and maintenance of performance and worship venues, good acoustics will be the result.

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The author, Johan Basse Bergqvist, is an engineer, a musician, and an audiophile with a knack for building projects that produce the desired results. The combination of these skills leads to a uniquely valuable perspective on audio design that is routinely reflected in the book and passed on to the readers. Several design projects are provided, 40 in total. The designs are explained, and the unique features or methods he uses are described in further detail. Each design includes detailed schematics and a complete parts list. Many of the projects also include layout documentation in the form of CAD photos of the PCB layouts. The range of projects is very diverse and includes something that will appeal to everyone. Stereo amplifiers, guitar and bass amplifiers, preamplifiers for phono, and microphones are all covered. Several variants for each type are included, and the power amplifier designs range from a few watts to several hundred watts, which meet almost any power level you might tackle.

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Valve Amplifiers are regarded by many to be the ne plus ultra when it comes to processing audio signals. The combination of classical technology and modern components has resulted in a revival of the valve amplifier. The use of toraidal-core output transformers, developed by the author over the past 15 years, has contributed to this revival. The most remarkable features of these transformers are their extremely wide frequency ranges and their very low levels of linear and nonlinear distortion. This book explains the whys and wherefores of toroidal output transformers at various technical levels, starting with elementary concepts and culminating in complete mathematical descriptions. In all of this, the interactions of the output valves, transformer and loudspeaker form the central theme. Next come the practical aspects. The schematic diagram of a valve amplifier often appears to be very simple at first glance, but anyone who has built a modern valve amplifier knows that a lot of critical details are hidden behind this apparent simplicity. These are discussed extensively, in connection with designs for amplifiers with output powers ranging from 10 to 100 watts. Finally, the author gives some attention to a number of special valve amplifiers, and to the theory and practice of negative feedback. In summary, this book offers innovative solutions for achieving perfect audio quality. Do-it-yourself builders, as well as persons who want to gain a deeper technical understanding of the complex world of audio transformers, valve amplifiers and audio signal processing, will find this book a rich and useful source of information.

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This comprehensive book on audio power amplifier design will appeal to members of the professional audio engineering community as well as the student and enthusiast. Designing Audio Power Amplifiers begins with power amplifier design basics that a novice can understand and moves all the way through to in-depth design techniques for very sophisticated audiophiles and professional audio power amplifiers. This book is the single best source of knowledge for anyone who wishes to design audio power amplifiers. It also provides a detailed introduction to nearly all aspects of analog circuit design, making it an effective educational text. Develop and hone your audio amplifier design skills with in-depth coverage of these and other topics: Basic and advanced audio power amplifier design Low-noise amplifier design Static and dynamic crossover distortion demystified Understanding negative feedback and the controversy surrounding it Advanced NFB compensation techniques, including TPC and TMC Sophisticated DC servo design MOSFET power amplifiers and error correction Audio measurements and instrumentation Overlooked sources of distortion SPICE simulation for audio amplifiers, including a tutorial on LTspice SPICE transistor modeling, including the VDMOS model for power MOSFETs Thermal design and the use of ThermalTrak transistors Four chapters on class D amplifiers, including measurement techniques Professional power amplifiers Switch-mode power supplies (SMPS)

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