PERSONAL PROJECT · HARDWARE · 2025

ESP32
WATCH

A dual-screen wristwatch designed from scratch with AI assistance — starting from zero KiCad knowledge. Custom two-board PCB architecture, ESP32-C3 MCU, USB-C charging, RTC timekeeping. An industrial designer learning EDA through build.

DESIGNED WITH AI · ZERO KICAD EXPERIENCE
HARDWARE SPEC REV 1
MCU ESP32-C3-MINI-1U-N4
Wi-Fi + BLE · 13.2 × 16.6mm
Displays
Display type SSD1306 OLED · I²C
RTC DS3231SN
Charging USB-C · TP4054 · 500mA
Regulator ME6211 · 3.3V LDO
Main board 31 × 16mm · 1.6mm · 2-layer · ENIG
Button board 31 × 5mm · 1.0mm · 3 buttons + OLED2
Idle draw ~0.5mA
Battery life ~16hr · 200mAh cell
EDA tool KiCad 10 · JLCPCB target
THE ANGLE

Industrial Designer.
Zero PCB Experience.

This project started with one question: could an industrial designer — someone who works in SolidWorks and KeyShot, not KiCad — design a functional PCB from scratch using AI as the EDA co-pilot? The answer turned out to be yes, with a lot of iteration.

01 The Starting Point

No EDA background. No prior schematic design. I knew what a PCB was but had never opened KiCad. The goal: design a complete, manufacturable two-board wristwatch with real components.

02 AI as Co-Pilot

Claude guided the full process — MCU selection, power architecture, component footprints, net classes, and DRC debugging. Every decision was reasoned through, not copy-pasted. I learned EDA by building the actual thing.

03 The Result

A complete two-board schematic with a documented power budget, per-component net classes, MOSFET power switching for battery life, and a 7-pin stacked board architecture. ERC clean. PCB layout in progress.

BOARD ARCHITECTURE

Two-Board Stack

A stacked two-board design: a main board (MCU, power, RTC, primary display) and a thin button board (3 tactile inputs + secondary OLED), linked by a 7-pin JST connector. Designed to fit a slim wristwatch enclosure.

MAIN BOARD 31 × 16mm · 1.6mm · BLACK ENIG
ESP32-C3-MINI-1U-N4 MCU · Wi-Fi + BLE
SSD1306 OLED #1 Primary display
DS3231SN RTC · ±2ppm
TP4054 LiPo charger · 500mA
ME6211 3.3V LDO regulator
2N7002 MOSFET OLED power cut · battery life
USB-C connector Edge-mount charging
BUTTON BOARD 31 × 5mm · 1.0mm · SLIM
SSD1306 OLED #2 Secondary display
3× Tactile switch User input
JST 7-pin Link to main board
DESIGN NOTE 1.0mm board for slim profile
BUILD STATUS

In Progress

Schematic complete, PCB layout underway. Routing not yet started — placement DRC being cleared. Target manufacturer: JLCPCB.

PHASE 01 Schematic COMPLETE
PHASE 02 PCB Placement IN PROGRESS
PHASE 03 PCB Routing NEXT
PHASE 04 Fabrication JLCPCB
POWER BUDGET

~16hr Mixed Use

Calculated on a 200mAh LiPo. A low-side MOSFET lets the ESP32 fully cut OLED1 power during sleep — the key design decision that makes the battery life viable.

COMPONENT MODE DRAW EST. mA
ESP32-C3Active (Wi-Fi off)Normal operation~20mA
SSD1306 OLED ×2ActiveBoth displays on~20mA
DS3231SNAlways onRTC timekeeping~0.2mA
ME6211 LDOAlways onQuiescent current~0.06mA
System (idle)Deep sleep · OLED offMOSFET cuts OLED1~0.5mA