A Linux Driver For USB-Based Projectors

There's a new Linux graphics driver for allowing mini/pico/compact/handheld USB-interfacing display projectors to work under your favorite distribution.

Earlier this week an email hit the Phoronix news inbox from Antonio Ospite, who has been working on this new driver support along with a Reto Schneider. While some of these small projectors have a VGA/HDMI interface (in which case no special Linux graphics driver is needed under Linux), a growing number of them are USB-based where only a Microsoft Windows driver is available. (If you're not familiar with these types of mini/handheld projectors, see the Texas Instruments projector demo from X@FOSDEM.)

With originally targeting an Acer C110, which is based upon an Actions Micro AM7212P chipset, a new open-source driver was born. For the USB projectors there's a simple packet-based protocol for the display ASIC to exchange the data between the host and the projector. Besides the Acer C110, this is reportedly the same design as several other Acer C-Series projectors, Philis PicoPix projectors, the CEL-TEC MP-o1, and various off-brand USB projectors.

Writing this new USB projector driver required reverse-engineering the USB protocol by USB dumps and disassembling the Microsoft Windows driver blob. According to the developers, their implementation will work on any lubusb-1.0 host, even if it's Google's Android platform.

This new ACM7xxx series driver though isn't a DRM/KMS driver or an X.Org driver (nor a V4L2/fbdev driver either for that matter) but more in the form of a user-space library with a display daemon that can be called upon for displaying content. For more details on the implementation or how to use this open-source USB projector driver, read these two posts.