Technical articles for small products.

ESP32-S31 now has an official Linux BSP Developer Preview. Here is a practical look at its MMU, Buildroot, U-Boot, Linux 6.18, build flow, and the limits that still matter.

How I run a small person-detection model on ESP32 with TensorFlow Lite Micro and ESP-NN, from memory limits to testing Espressif's example.

A practical guide to PCB net classes and trace width for small boards: signal traces, 3V3, 5V, battery paths, ground, power vias, and a pre-Gerber checklist.

A practical guide to PCB ground planes, return current, GND layout mistakes, stitching vias, decoupling paths, and copper pour checks.

Learn how MEMS microphones work, how analog, PDM, and I2S outputs differ, and how to avoid PCB, power, and acoustic-port mistakes.

A beginner guide to choosing capacitors for circuits: capacitance, voltage rating, decoupling, ceramic types, DC bias, and ESP32 values.

A beginner-friendly SMD soldering guide covering tools, easy parts, resistors, capacitors, multi-pin ICs, flux, hot air, and PCB inspection.

Review an ESP32-S3 battery power path from USB-C and TP4056 charging to protection, load sharing, 3.3V regulation, and load budget.

Analyze battery life for an ESP32 robot with a display: backlight, Wi-Fi, audio, peripherals, sleep modes, wake sources, and runtime.

Build a Mochi Robot emotion state machine for idle, listening, talking, happy, sad, thinking, and error states with replaceable animations.

A practical PCB review checklist before fabrication: schematic, ERC, footprints, clearance, power, antenna, USB pairs, silkscreen, Gerbers, and BOM.

A practical guide to animated GIF expressions in ESP32 firmware: convert assets, enable LV_USE_GIF, store files, and render with lv_gif.

Comparing ESP32-C3 and ESP32-S3 on GPIO, RAM, PSRAM, USB, I2S, and LVGL headroom, with a concrete recommendation for a basic Mochi build and a Mochi AI build.

Compare GIF, PNG, JPG, and C array images for ESP32 displays by flash use, RAM use, decode speed, alpha, animation, and quality.

An ESP32 TouchDown case study for reviewing an open-source schematic before reuse, covering power, reset, boot, USB, connectors, and tests.

A practical explanation of BCLK, WS, DIN, DOUT, full-duplex audio, sample rate, and buffers when building two-way I2S audio on ESP32-S3.

A practical breakdown of ESP32-S3 Mochi Robot hardware: display, touch, I2S microphone, amplifier, speaker, battery, charging, and GPIO.

How LVGL helps build emotional interfaces for Mochi Robot, including expressions, menus, battery status, and UI on small embedded displays.

Part 2 of the Mochi LVGL series, covering faces, expressions, battery status, connectivity, screens, components, and UI states.

What embedded UI means for small devices, why small screens have small budgets, and why it deserves attention as its own discipline.

Early principles for firmware on a small embedded product: scope, module boundaries, logging, and handling errors without guessing.

The first Mochi devlog: early hardware questions, first firmware decisions, and what already went wrong.

A short introduction to Mochi, a small robot developed as an exercise in hardware, firmware, and product experience.

Initial principles for designing hardware for a small product: scope, power, PCB layout, firmware, and debugging.

How Nastrotek prepares and shares design files, templates, source code, and free documents clearly.