Tutorials

Audio spectrum analyzers are fascinating projects that combine digital signal processing, microcontroller programming, and LED control to create mesmerizing visual displays. Building a 32-band spectrum analyzer with an Arduino provides an excellent opportunity to learn about Fast Fourier Transforms (FFT), real-time audio processing, and LED matrix control while creating something genuinely impressive for your workshop or music setup. Understanding the Basics A spectrum analyzer works by breaking down an audio signal into its component frequencies and displaying their amplitudes visually. The “32-band” designation means we’re dividing the audible frequency range into 32 distinct frequency bins, each represented by a column of LEDs. When music plays, each column lights up to a height proportional to the energy present in that frequency range, creating a dynamic waterfall effect that dances to the beat. ...

The convergence of artificial intelligence and embedded audio processing represents one of the most exciting developments in DIY electronics. Machine learning models that once required powerful GPUs can now run on microcontrollers, enabling intelligent audio applications from noise cancellation to musical instrument recognition, all happening in real-time on devices costing just a few dollars. The Embedded AI Revolution Traditional digital signal processing relies on hand-crafted algorithms based on our understanding of audio physics and psychoacoustics. While effective, these approaches require expert knowledge to design and often struggle with complex, variable real-world conditions. Machine learning flips this paradigm, learning patterns directly from data and generalizing to handle situations their designers never explicitly programmed. ...

Distortion pedals remain among the most popular DIY guitar effects projects, offering an ideal balance of circuit simplicity and sonic satisfaction. Understanding how distortion circuits work demystifies not just pedal design but fundamental concepts in audio electronics, from amplification and clipping to tone shaping and impedance matching. Whether you dream of recreating classic tones or inventing your own signature sound, grasping distortion fundamentals opens the door to creative circuit design. ...

VU meters have captivated audio enthusiasts since their introduction in broadcast studios decades ago, providing visual feedback of audio levels through mechanical needle movement. Modern LED versions bring this classic aesthetic into the digital age with colorful displays that react instantaneously to music. Building an Arduino-based LED VU meter or audio visualizer combines audio signal processing, microcontroller programming, and LED control techniques into one visually rewarding project perfect for your workbench, entertainment system, or live performance setup. ...

Mehdi Sadaghdar’s ElectroBOOM channel has become legendary for its unique combination of rigorous electrical engineering education and comedic presentation involving deliberate (and sometimes accidental) electrical mishaps. With over 5 million subscribers, Mehdi’s approach to teaching electronics through entertainment makes complex topics accessible while never compromising technical accuracy. His power amplifier tutorials exemplify this approach, breaking down intimidating audio circuits into understandable concepts while keeping viewers thoroughly entertained. The ElectroBOOM Educational Philosophy What makes ElectroBOOM’s teaching style so effective is the willingness to directly address misconceptions and explain why common approaches fail. Rather than simply presenting working designs, Mehdi often demonstrates what doesn’t work and explains precisely why. This negative-space learning—showing boundaries of what’s possible—builds deeper understanding than positive examples alone. When Mehdi deliberately shorts an output or forgets proper biasing, the dramatic (sometimes pyrotechnic) results make the underlying principles unforgettable. ...

Clean boost pedals represent the simplest and most elegant of guitar effects, providing pure signal amplification without coloration or distortion—at least, that’s the ideal. These minimal circuits teach fundamental amplification concepts while delivering genuinely useful functionality. Whether pushing an amp into saturation, compensating for signal loss through long cable runs, or simply adding volume for solos, a well-designed boost pedal solves real problems with refreshingly straightforward circuitry. Building one makes an perfect introduction to audio electronics and effects pedal design. ...

Environmental sound recognition represents one of the most practical applications of embedded machine learning, enabling devices to understand their acoustic surroundings and react intelligently. Unlike speech recognition that focuses on linguistic content, environmental sound classification identifies non-speech audio events: glass breaking, dogs barking, machinery malfunctioning, or babies crying. Running these recognition algorithms directly on microcontrollers—without cloud connectivity—opens possibilities for responsive, privacy-preserving, low-latency audio applications across countless domains. Why Environmental Sound Recognition Matters Traditional audio systems react to simple thresholds—sound present or absent, loud or quiet—providing crude detection at best. Machine learning enables nuanced understanding: distinguishing wanted sounds from background noise, recognizing specific audio events among many possibilities, and adapting to acoustic variability that defeats rule-based algorithms. This capability transforms devices from simple sensors into intelligent listeners that understand context. ...