The new USI 2.0 standard for styluses isn’t so universal after all

Image: Lenovo

Compatibility issues with version 2.0 of the Universal Stylus Initiative (USI) standard mean older USI 1.0 styluses won't work with some newer USI 2.0 devices. When it noticed that existing styluses weren't working with the device, ChromeUnboxed discovered the problem.

The screen of the Duet 3 uses an in-cell design that combines elements of the display with a digitizer that handles stylus input, making it difficult to use. This is a more cost effective way to offer stylus input. The Duet 3 isn't compatible with styluses made to work with USI 1.0 displays.

The limitation was confirmed by the chairman of USI. The touch and display driver are more tightly integrated for in-cell, so the touch has to occur in between the display being driven. We had to modify our USI spec for some in-cell panels due to the timing constraint. It was not possible to ensure backwards compatibility.

It is not clear if the problem affects all USI 2.0 compatible displays, but it is an unfortunate limitation that restricts the amount of styluses that can be used with devices that use in-cell tech. There aren't that many compatible styluses on the market, and even the USI Pen 2 doesn't seem to be available yet.

Consumers are at risk of being confused. It is not clear how many vendors will take steps to mitigate this. In order to minimize the confusion and user frustration, we have requested clear documentation and marking, as well as shipping with a 2.0.

Support for styluses that can be charged wireless is one of the features of USI 2.0.

The Universal Stylus Initiative is not the only organization that has had compatibility issues with the standard. There is a confusing mess of standards offered by the USB Implementers Forum. There is a difficult balance to be struck between controlling how technology can be used to avoid confusion and leaving them open enough to encourage wide adoption.

Even though a device supposedly supports a universal standard, you have to keep an eye on the fine print.