LPen

LPen is a family of digital writing instruments and an input protocol designed to standardize pen input across devices. Developed by the LPen Alliance, LPen hardware combines a rechargeable stylus with replaceable nibs and a wireless transmitter to deliver handwriting and drawing input to compatible touchscreens. The LPen Protocol supports up to 4096 pressure levels, tilt detection, and palm rejection, with low latency designed to emulate the feel of a traditional pen.

The LPen concept emerged from industry collaboration in 2018 as an open standard intended to compete with vendor-locked styluses. A first generation of LPen devices was released in 2020, followed by the LPen Pro and LPen Mini lines in subsequent years. The standard is periodically updated to add features such as higher sampling rates, improved battery efficiency, and expanded device compatibility.

Hardware details: LPen uses a rechargeable battery, USB-C charging, and replaceable nibs. Communications: Bluetooth Low Energy or wired USB-C mode; the protocol includes nib identification, button states, pressure data, tilt data, and battery status. Compatibility: designed to work with a broad range of operating systems that expose pen input APIs, including Windows, macOS, Android, and select Linux distributions; specific features may require vendor drivers or host apps.

In practice, LPen has found adoption in education, digital art, and note-taking scenarios. Praise centers on low latency, precise pressure sensitivity, and comfortable ergonomics; criticisms include uneven third-party app support and ongoing nib availability costs.

Variants include LPen Classic (entry-level), LPen Pro (enhanced sensitivity and dual-tap gestures), and LPen Mini (compact form). Several manufacturers license the LPen Protocol, which has also spurred competition and derivative designs.