Teensy Accel

This turns the Teensy 4.1 development board into a usb->usb filter with mouse acceleration.

Hardware

Besides a Teensy 4.1 board and a micro USB cable, you'll need to get, and solder, 5 header pins for the USB host cable.

Installation

• Follow the Teensyduino installation guide

  Note Teensyduino (as of v1.57) is only compatible with the legacy Arduino IDE (v1.8.19)

• Open teensy-accel.ino in the Arduino IDE
• Edit the Raw Accel profile_settings definition in accel.hpp
• In the IDE Tools menu, ensure "Teensy 4.1" and "Keyboard + Mouse + Joystick" are selected under Board and USB Type
• Plug in the board and click 'Upload'

Limitations

• Input device is expected to request 1000hz polling rate
• Output movement values are represented by 1 byte (max counts = 127); inputs from faster motions could get clamped, depending on settings and dpi