The Pencreus — ESP32-S3-RLCD-4.2 Weather Station

Retro terminal aesthetic on a sunlight-readable 4.2" reflective LCD. Boot splash with brand character, live clock (NTP + RTC), outdoor weather with sunrise/sunset, indoor temp/humidity, and an animated Eyebot orb mascot with listening/responding states.

Hardware

Part	Notes
Waveshare ESP32-S3-RLCD-4.2	400×300 reflective LCD, no backlight needed
Onboard SHTC3	Indoor temp + humidity
Onboard PCF85063 RTC	Keeps time without WiFi
18650 battery holder	Very long runtime — no backlight drain

Wiring

Everything is onboard — no external connections needed.

Arduino IDE Setup

1. Add ESP32 board manager URL: https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json
2. Install esp32 by Espressif 2.0.x
3. Board settings: ESP32S3 Dev Module
   • Flash Size: 16MB
   • PSRAM: OPI PSRAM 8MB
   • Upload Speed: 921600
4. Install via Library Manager:
   • U8g2 by Oliver Kraus
   • ArduinoJson by Benoît Blanchon
5. Install Waveshare custom libraries (only SensorLib + U8g2 needed — skip LVGL):

   git clone https://github.com/waveshareteam/ESP32-S3-RLCD-4.2
   cp -r ESP32-S3-RLCD-4.2/01_Arduino_Libraries/SensorLib ~/Arduino/libraries/
   cp -r ESP32-S3-RLCD-4.2/01_Arduino_Libraries/U8g2     ~/Arduino/libraries/

Configuration

Edit ESP32_RLCD_Display/secrets.h before flashing:

• WIFI_SSID / WIFI_PASS — your network (pre-filled)
• OWM_API_KEY — OpenWeatherMap key (pre-filled)
• OWM_LAT / OWM_LON — your GPS coordinates
• HA_TOKEN — Home Assistant long-lived token (optional)

File Structure

ESP32-RLCD/
├── mockup/
│   ├── index.html          ← Live browser mockup (http://localhost:7842)
│   ├── logo.svg            ← Brand character (splash only)
│   ├── logo_1bit.png       ← 56×72 px 1-bit reference
│   └── logo_splash.png     ← 120×154 px splash reference
├── ESP32_RLCD_Display/
│   ├── ESP32_RLCD_Display.ino  ← Main sketch
│   ├── config.h                ← Pins, addresses, intervals
│   ├── secrets.h               ← WiFi + API keys (git-ignored)
│   ├── splash_logo_xbm.h       ← 120×154 px boot splash bitmap
│   └── logo_xbm.h              ← 56×72 px (unused — kept for reference)
├── .gitignore
└── README.md

Display Layout (400×300 landscape)

┌─ THE PENCREUS  //  PERSONAL STATUS MONITOR ────────────────┐  ← header
│  THU              │  21:59:22                               │  ← date/clock
│  21 MAY 2026      │              LOCAL · PST8PDT            │
├───────────────────────────────────────────────────────────┤
│  // OUTDOOR WEATHER [OWM]                                  │
│  Partly Cloudy    72°F     HUMIDITY 45%  FEELS 69°F        │
│  H:78° · L:61°   SR:06:14 · SS:20:47                      │
├───────────────────────────────────────────────────────────┤
│  // INTERIOR [SHTC3]          │  [EYEBOT ORB ANIMATION]   │
│  TEMP  68.4°F                 │    ◎  floating / pulsing  │
│  RH    45.1%                  │                            │
├───────────────────────────────────────────────────────────┤
│  ● WIFI:OK  |  SSID:AROUTERSPACE  |  STATUS:NOMINAL        │
└───────────────────────────────────────────────────────────┘

KEY Button

Press the onboard KEY button (GPIO 0) to cycle: IDLE → LISTENING (pulse rings + antenna wiggle) → RESPONDING (speech arcs) → IDLE