Quelltext der Seite WSAL17341 – 4.2inch NFC-Powered e-Paper/en

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'''Documentation notice:''' This technical documentation was independently rewritten from an archived supplier source. Check technical details and commands against the product version and manufacturer documentation before use.

== Summary ==
The 4.2inch module is powered via NFC and transfers image data wirelessly. It requires no battery and retains the last displayed content without power. This document summarizes specifications, usage steps, and notes.

== Related products at JW Tech ==
* [https://shop.jw-tech.eu/p/WSAL17341 WSAL17341 – 4.2inch Passive NFC-Powered e-Paper, No Battery]
* [https://shop.jw-tech.eu/p/WSAL17765 WSAL17765 – 4.2inch NFC-Powered e-Paper Evaluation Kit, Wireless Powering &amp; Data Transfer]

== Technical overview ==
* Resolution: 400 x 300 pixels; color: black and white
* Dot pitch: 0.212 mm × 0.212 mm; display size: 84.8 mm × 63.6 mm
* Housing dimensions: 105.0 mm × 94.1 mm × 9.90 mm; viewing angle &gt; 170°
* Refresh time: approximately 4 seconds
* Onboard interface on main board: SPI
* PCB version Rev2.2 (latest): NFC chip replaced, fast flashing method; update mobile app and ST25R3911B program before use
* Android app requires Android 4.0 (Ice Cream Sandwich) or newer; Samsung, Google, and Sony devices are not supported
* Initial device password: 1234
* ST25R3911B NFC Board: factory-flashed program included; SW download port available for updates
* Operating conditions: temperature 0–50 °C, humidity 35–65% RH
* Storage conditions: below 30 °C, below 55% RH, maximum 6 months
* Transport conditions: −25–70 °C, maximum 10 days
* After unpacking: 20 °C ± 5 °C, 50 ± 5% RH, assemble within 72 hours

== Notes and version constraints ==
* Phone's NFC function must be enabled; do not move the device during transmission to improve success rate
* Image resolution must exactly match the display resolution; special cases: 2.13inch = 122×250, 2.9inch = 128×296
* Scan QR code using browser scan function only, not via WeChat
* Install or update the latest app and ST25R3911B program before use
* If refresh fails: remove the reader, reposition it, and retry
* No warranty, certification, or pricing information is provided in this source

== Source and revision record ==
* [https://www.waveshare.com/wiki/4.2inch_NFC-Powered_e-Paper 4.2inch NFC-Powered e-Paper - Waveshare Wiki]
* Source revision: 99242
* Captured: 2026-08-31T04:13:47+00:00
* SHA-256: <code>4c5f0629c3cc22e0ee3b1ca861866043727686375231bbedf7558617d89dd7d0</code>