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  "path": "/2026/04/26/lightink-an-esp32-based-solar-powered-e-ink-smartwatch-with-up-to-10-months-of-battery-life/",
  "publishedAt": "2026-04-26T09:14:05.000Z",
  "site": "https://www.cnx-software.com",
  "tags": [
    "Espressif",
    "Hardware",
    "Video",
    "C/C++",
    "e-ink",
    "epaper",
    "esp32",
    "IoT",
    "kicad",
    "lora",
    "low power",
    "open source",
    "smartwatch",
    "solar",
    "wearables",
    "wireless",
    "LightInk – An ESP32-based, solar-powered E-ink smartwatch with up to 10 months of battery life",
    "CNX Software - Embedded Systems News"
  ],
  "textContent": "Daniel Ansorregui has developed LightInk, an open-source solar-powered E-ink watch inspired by 90s solar digital watches. It features a 1.54-inch e-paper display and supports Wi-Fi, Bluetooth, LoRa, and GPS, running on a 100mAh battery. The project integrates a custom low-quiescent-power design using a TPS63900 buck-boost converter, capacitive-touch input, and deep-sleep-driven firmware, along with ultra-fast partial e-ink updates (<1 ms active time) and precise RTC timekeeping with drift calibration. It also supports solar-first operation (no dedicated charging IC) and dynamic power gating of peripherals, enabling around 9–10 months of operation on a small battery supplemented by solar power. LightInk specifications: System-in-package – ESP32-PICO-D4 SiP CPU – Dual-core processor @ 240MHz Memory – 520KB SRAM Storage – 4MB flash Wireless – 2.4 GHz Wi-Fi 4 up to 150 Mbps and Bluetooth 4.2 BR/LE connectivity Display – 1.54-inch 200×200 B/W e-Paper panel (GDEH0154D67 or compatible) Audio – 10-15mm piezo electric disc speaker Connectivity [...]\n\nThe post LightInk – An ESP32-based, solar-powered E-ink smartwatch with up to 10 months of battery life appeared first on CNX Software - Embedded Systems News.",
  "title": "LightInk – An ESP32-based, solar-powered E-ink smartwatch with up to 10 months of battery life"
}