Hardware

Everything tagged “Hardware” across notes, resources, and Mochi logs.

ESP32-DevKitC V4 and an RS-485 transceiver laid out on an electronics workbench

NotesFirmwareSeptember 7, 2026

Industrial IoT with ESP32: Modbus and Real-Time Control

A practical guide to Modbus TCP, Modbus RTU over RS-485, and PLC communication with ESP32 for reliable industrial IoT prototypes.

Firmware Hardware IoT Solutions ESP32 Modbus Modbus RTU Modbus TCP PLC Industrial IoT Real-Time Control

Three Bluetooth module boards arranged on a used ESD workbench beside a multimeter and precision screwdriver

NotesHardwareSeptember 6, 2026

HC-05 vs HM-10 vs BLE 5.0: Which Bluetooth Module Should You Choose?

Compare HC-05, HM-10, and BLE 5.0 modules by Bluetooth Classic, BLE GATT, UART, phone support, range, power, and integration for Arduino, ESP32, and IoT projects.

Bluetooth Bluetooth Classic BLE Arduino ESP32 IoT Hardware

ESP32 development board being checked with multimeter probes on a practical electronics workbench

NotesHardwareAugust 31, 2026

18 Common ESP32 Errors and How to Fix Them – Part 1

How I troubleshoot eight common ESP32 problems: flashing, boot mode, brownouts, serial, GPIO, I2C, SPI, and custom PCB bring-up.

ESP32 Troubleshooting Hardware ESP-IDF IoT

Camera-equipped ESP32-S3 prototype running person detection locally on a workbench

NotesFirmwareAugust 18, 2026

TinyML on ESP32: Running AI on the Device

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.

Firmware Hardware ESP32-S3 TinyML Machine Learning Edge AI

Annotated PCB view comparing narrow signal traces with a wider power trace

NotesPCB DesignAugust 12, 2026

Net Classes and Trace Width: When Should a PCB Trace Be Wider?

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.

PCB Design Hardware ESP32 Power Design KiCad

Original diagram showing a signal trace and its compact return path over a continuous ground plane

NotesPCB DesignAugust 12, 2026

PCB Ground Planes: GND Is More Than a Net Name

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

PCB Design Hardware ESP32 Power Design KiCad

Macro photo of a MEMS microphone package showing its acoustic port and package marking

NotesHardwareAugust 10, 2026

What Is a MEMS Microphone? From a Silicon Diaphragm to ESP32 Audio

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

Hardware Firmware ESP32-S3 MEMS Microphone I2S Embedded Audio Mochi

Close-up of SMD capacitors and resistors on a printed circuit board

NotesPCB DesignAugust 7, 2026

Choosing Capacitors for Electronics: Simple Part, Easy Mistake

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

PCB Design Hardware Capacitors Power Design ESP32

Close-up of a soldering iron working on a small SMD capacitor on a PCB

NotesPCB DesignAugust 7, 2026

How to Hand-Solder SMD Components for Beginners

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

PCB Design Hardware SMD Soldering

Top-view PCB render of the ESP32-S3 battery power reference design used in the article

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NotesHardwareAugust 6, 2026

ESP32 Battery Power Design: From USB-C Charging to the 3.3V Rail

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

Hardware PCB Design ESP32-S3 USB-C Li-ion Power Design

Diagram of active, idle and sleep states used to reduce ESP32 display power consumption

NotesFirmwareAugust 6, 2026

Extending Battery Life in an ESP32 Robot with a Display

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

Firmware Hardware Mochi ESP32-S3 Power Management Battery Life

A PCB board next to a checklist clipboard being reviewed before fabrication

NotesPCB DesignAugust 5, 2026

A Practical PCB Review Checklist Before You Send It to Fab

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

PCB Design Hardware Checklist KiCad

Opened Mochi prototype showing the controller, display, wiring and 3D-printed enclosure used during early hardware experiments

MochiHardwareAugust 5, 2026

Complete Hardware Architecture for an ESP32-S3 Mochi Robot

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

Mochi Hardware ESP32-S3 Firmware

ESP32-C3 board with a small OLED next to an ESP32-S3 board with a color display and speaker

NotesHardwareAugust 5, 2026

ESP32-C3 or ESP32-S3: Which Chip for a Robot with a Screen and Audio?

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.

Hardware Product Design ESP32-C3 ESP32-S3 Mochi

ESP32-S3 reference schematic divided into functional blocks for review

NotesPCB DesignAugust 5, 2026

Reading an Open-Source ESP32 Schematic Before Reusing It

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

PCB Design Hardware ESP32 Open Source

Original open robot prototype showing its controller, speaker, battery and display hardware

NotesFirmwareAugust 5, 2026

Two-Way I2S Audio on ESP32-S3: I2S Microphone and I2S Speaker

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

Firmware Hardware ESP32-S3 Audio I2S

Mochi robot face interface on a small embedded display built with LVGL

MochiEmbedded UIJuly 28, 2026

LVGL and Mochi Robot: Building Emotional Interfaces for Embedded Devices - Part 1: The Power of LVGL in UI/UX Programming

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

Mochi UI/UX Hardware Programming

LVGL interface flow for Mochi robot emotional states and screen animations

MochiHardwareJuly 28, 2026

LVGL and Mochi Robot: Building Emotional Interfaces for Embedded Devices - Part 2: Mochi & LVGL

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

Mochi UI/UX Hardware Programming

Hand-held embedded display prototype running a real LVGL interface

NotesEmbedded UIJuly 27, 2026

What Is Embedded UI, And Why It Matters

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

Embedded UI Product Design Hardware

Opened Mochi prototype showing the ESP32 board, display wiring and 3D-printed enclosure

NotesFirmwareJuly 26, 2026

First Notes On Firmware For Embedded Products

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

Firmware Hardware Embedded UI

Opened Mochi prototype showing the wiring and enclosure compromises from early development

MochiProduct DesignJuly 25, 2026

Mochi Devlog 01: Early Development

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

Mochi Hardware Firmware

Original Mochi workshop prototype with a 3D-printed enclosure and OLED face

MochiProduct DesignJuly 21, 2026

What Is Mochi?

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

Mochi Hardware Firmware

Real assembled AQuality32 PCB shown from both sides with its battery and main circuit blocks

NotesHardwareJuly 20, 2026

First Notes On Hardware Design For Small Products

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

Hardware PCB Design Firmware