Huy Vector of HVT Lab skipped the dev board in a plastic box and built a talking assistant from an ESP32-C3, a 0.96-inch OLED face, a microphone, a smartphone speaker and a rechargeable battery. It's all soldered into an open brass frame, and the whole thing is about two fingers wide.

Fancy higher-quality audio than MP3 from a microcontroller? With CircuitPython Turbo on fast boards like the ESP32-S3 and RP2350, you can now play FLAC and Ogg Vorbis files. This guide walks you through it using the Adafruit Feather ESP32-S3 and the Fruit Jam.

Not sure whether that resistor will cope with the load? Enter any two of voltage, current and resistance, and this calculator fills in the third, works out the power dissipated and suggests a safe minimum wattage. You can set the safety factor yourself, with ×2 as a sensible default.

Want to flip a GPIO on your ESP32 from any device on your network? This ESP-IDF tutorial shows you how to build a local web server that serves a simple HTML interface with TURN ON and TURN OFF buttons. Type in the board's IP address, click a button, and the pin responds.

If you've ever wanted a clear picture of analogue-to-digital conversion, this introduction to PCM is a good place to start. You'll see how a signal is sampled, mapped to a fixed set of levels and turned into binary. You'll also learn why an anti-aliasing filter is used to avoid distortion.

Picture a small chatbot with a touchscreen interface and no internet connection needed. PocketGPT runs on both an ESP32-S3 DevKit and a XIAO ESP32S3, using a model trained from scratch and shrunk with Q4 quantisation. Answers can be hit and miss, but it's a neat look at what these boards can handle.

Tired of a rat's nest of Dupont wires on a robot that moves? This shield plugs onto an Arduino Mega and gives the wheels, arm, end-stops and servos their own keyed connectors. Every Mega pin is still broken out on headers, so you can reach anything for debugging or expansion.

Want to keep an eye on a parent or patient without putting a camera in the room? This project uses LD2410C presence sensors wired to ESP32 boards to log which rooms are occupied and when. Machine learning then looks for anomalies, and caregivers and family can follow along through a React web frontend.

Curious what "AI on a microcontroller" actually means in practice? This is a down-to-earth look at small, trained models doing one specific job locally, nothing like ChatGPT. You'll see how training happens on a workstation or in the cloud, while the device simply runs inference with frozen weights.

Here's a hands-on way to learn how CMOS logic works. You'll follow three gates from LTspice simulation through schematic and PCB design to fabricated, assembled boards. Each board is then checked against its truth table using an Arduino to generate the input signals, so you can see the theory working on real hardware.

Starting with how a keyboard turns a key press into a note, this guide takes you through a breadboard piano built around an Arduino and a passive buzzer. Each button plays a note of the C major scale, and it's a great first project for getting to grips with digital inputs.