Orologio E-Ink

E-ink desk clock with a 3.7" display, ESP32-C3 and LiFePO4 battery. Connects to WiFi, syncs time via NTP and runs for about 2 years on a single ~2-hour USB-C charge.

Philosophy: "Place it and it works. Recharge it every 2 years."

Features

• 3.7" e-ink display (240x416 px) — sunlight readable, zero power draw at rest
• ESP32-C3 in deep sleep (~5 µA), wakes up every minute to update the display
• External 32.768 kHz crystal for accurate deep-sleep timekeeping (~1.7 s/day drift)
• Automatic nightly NTP sync to correct drift
• 2x LiFePO4 18650 cells in parallel (3600 mAh) — USB-C charging via TP5000
• Multiple battery chemistry support: LiFePO4, Li-Po, 3x AA alkaline (configurable via firmware and jumpers)
• WiFi setup via captive portal (WiFiManager) — no serial cable needed
• Automatic DST handling with IP geolocation
• Optional telemetry to Google Sheets (battery voltage, USB status, location)
• Custom PCB designed in KiCad and manufactured on JLCPCB

Hardware

Component	Model
MCU	ESP32-C3-MINI-1
Display	WeAct Studio 3.7" e-Paper (GDEY037T03, driver UC8253)
Battery	2x LiFePO4 18650 1800 mAh in parallel
Charger IC	TP5000 (CC/CV, cutoff 3.6 V)
LDO	MCP1700-330
Connector	USB Type-C
Crystal	32.768 kHz SMD 3215

Full pinout and circuit details are in docs/specifiche.md.

Repository structure

firmware/
  orologio_secondi.ino      # Arduino firmware (ESP32-C3)
  setup.html                 # WiFi configuration page (captive portal)
  telemetria_apps_script.js  # Google Apps Script for telemetry
pcb/
  progetto.kicad_pro         # KiCad 8 project
  progetto.kicad_sch         # schematic
  progetto.kicad_pcb         # PCB layout
  libs/                      # custom libraries and LCSC components
  loghi/                     # SVG logos on the board (CE, RoHS)
  production/                # Gerber, BOM, pick & place for JLCPCB
docs/
  specifiche.md              # full technical specifications

Firmware setup

Dependencies (Arduino IDE / PlatformIO)

• Board: esp32 by Espressif (ESP32-C3)
• GxEPD2
• U8g2_for_Adafruit_GFX
• WiFiManager

Battery configuration

In orologio_secondi.ino, uncomment the line matching the installed battery pack:

#define BATTERIA_LIFEPO4    // LiFePO4 (default)
//#define BATTERIA_LIPO     // Li-Po / Li-ion
//#define BATTERIA_3AA      // 3x AA alkaline

This must match the jumper configuration on the PCB (JP_DIODE, JP_LDO, JP_CS).

First boot

1. Power on the clock
2. Hold the button for 3 seconds
3. Connect your phone to the "orologio" WiFi network
4. Select your home WiFi and enter the password
5. The clock syncs via NTP and displays the time

PCB

The KiCad project is in pcb/. The production/ folder contains files ready for ordering on JLCPCB:

• progetto.zip — Gerber files
• bom.csv — Bill of Materials with LCSC part numbers
• positions.csv — pick & place file

License

This project is open source. See the LICENSE file for details.