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.