Source: https://mokxi.com/libraries/mouse Updated: 2026-11-02 Libraries / Communication Arduino library · Communication # The Arduino Mouse library: move the pointer from a board Mouse.h lets a board with native USB act as a mouse. Like the Keyboard library it needs an ATmega32U4 board (Leonardo, Micro, Pro Micro) or another board whose chip is a USB device; an Uno cannot do it. The computer sees an ordinary three-button mouse with a scroll wheel. Open the example in the editor See the calls Built in on Mokxi: #include and it builds, with nothing to install. Free, and no account needed. ## What Mouse does A mouse reports relative motion, not a position. Mouse.move(x, y) means "move this many counts from wherever the pointer is now", each from -128 to 127, and the computer’s pointer speed setting decides how far that is on screen. To steer it with a thumb joystick, read the two axes, subtract the center reading, scale it down to a few counts, and send that every 10 ms or so. Buttons are held or tapped: click() is a quick press and release, while press() and release() let a sketch drag. A stray mouse that never stops moving makes a computer very hard to use, so keep an on and off switch in every sketch while you develop. Library Manager name | Mouse Author | Arduino Include | #include Boards | Arduino Leonardo, SparkFun Pro Micro, Arduino Micro In the simulator | Runs, with a gap the note below names. ## Install it It builds on Arduino Leonardo, SparkFun Pro Micro, Arduino Micro. In Mokxi it is built in: #include and the sketch compiles, with no download, no zip and no Library Manager. On a real board it comes with the board package (Arduino), so the Arduino IDE has it as soon as the board is installed: there is nothing to add from the Library Manager. Arduino Leonardo · SparkFun Pro Micro · Arduino Micro ## The calls you will use In the order a sketch meets them. ### Mouse.begin() Starts acting as a mouse. Call once in setup(). ### Mouse.move(xDistance, yDistance, wheel) Moves the pointer by that many counts, each from -128 to 127. The third number scrolls the wheel; leave it out for 0. ### Mouse.click(MOUSE_LEFT) Presses and releases a button. MOUSE_RIGHT and MOUSE_MIDDLE are the others. ### Mouse.press(MOUSE_LEFT) Holds a button down, for dragging, until release() is called. ### Mouse.release(MOUSE_LEFT) Lets the held button go. ### Mouse.isPressed(MOUSE_LEFT) True while the sketch is holding that button, handy to avoid sending the same press twice. ### Mouse.end() Stops sending mouse reports. ## Example: Key matrix numpad On the SparkFun Pro Micro. It runs in the browser exactly as printed. sketch.ino · SparkFun Pro Micro The sketch is cut short here; the editor has every line of it. Open it in the editor, wired and ready to run · Key matrix numpad: the project page ## Common errors and how to fix them ### The pointer drifts on its own with the joystick at rest A centered joystick rarely reads exactly 512. Subtract its real resting reading taken at start-up, and ignore small values (a dead zone of 10 or 20 counts) before calling move(). ### The pointer flies across the screen and the computer is unusable The sketch sends large moves too often. Divide the readings down, add a short delay between reports, and guard the whole thing with a switch read by digitalRead() so you can turn the mouse off. ### 'Mouse' not found, or Mouse.h does not build Include Mouse.h at the top of the sketch and pick a board with native USB such as a Leonardo, Micro or Pro Micro. An Uno or Nano cannot act as a mouse. ## Keep going ### Learn - Arduino Joystick Module: Wiring, Code, Live Demo - Arduino Leonardo Pinout: I2C, SPI on ICSP, A6-A11 ### More communication libraries - OneWire - TinyGPS - TinyGPSPlus - MFRC522 - SoftwareSerial - AltSoftSerial - i2cdetect - Keyboard Every built-in library · Open the editor ## Try Mouse without installing anything Open the example, change the sketch, and keep your version in a free account. Start building free Open the editor