{"id":10,"date":"2026-02-14T07:44:40","date_gmt":"2026-02-13T23:44:40","guid":{"rendered":"https:\/\/www.justrobotics.com\/wp\/?p=10"},"modified":"2026-02-14T20:48:02","modified_gmt":"2026-02-14T12:48:02","slug":"building-a-simple-keyboard-emulator-with-arduino-pro-micro","status":"publish","type":"post","link":"https:\/\/www.justrobotics.com\/wp\/2026\/02\/14\/building-a-simple-keyboard-emulator-with-arduino-pro-micro\/","title":{"rendered":"Building a Simple Keyboard Emulator with Arduino Pro Micro"},"content":{"rendered":"\n\n\n\n\n
\"keyboard<\/figure>\n\n\n\n

Years ago, when I worked on my first keyboard\u2011emulation project, I used a Teensy<\/a> <\/a>microcontroller. It was a great experience, and the Teensy<\/strong> performed perfectly \u2014 but it was overkill: too powerful and a little too pricey.<\/p>\n\n\n\n

Nowadays, there\u2019s no shortage of microcontrollers that can emulate a keyboard or mouse. I recently got my hands on an Arduino Pro Micro clone, which I bought from AliExpress <\/a>for about US$5 (shipping included). There are even cheaper options out there, but I haven\u2019t had the chance to play with them yet. \ud83d\ude0a<\/p>\n\n\n\n

What Is an Arduino Pro Micro?<\/strong><\/h2>\n\n\n\n

The Arduino Pro Micro is built around the ATMEGA32U4<\/strong> chip. This chip is what allows it to behave like a HID \u2014 a Human Interface Device<\/em>.<\/p>\n\n\n\n

Using the Arduino IDE<\/a> (for simplicity, though it\u2019s not strictly required), you can program it to act like a keyboard or mouse. Your wish is the Arduino\u2019s command!<\/p>\n\n\n\n

Why Keyboard Emulation?<\/strong><\/h2>\n\n\n\n

I\u2019m glad you asked! \ud83d\ude0a<\/p>\n\n\n\n

There are plenty of interesting use cases, but let me start with a personal one. Once upon a time, I wanted to automate the login sequence on my Windows laptop.<\/p>\n\n\n\n

[MCU plugged into laptop]\nKeystrokes: CTRL + ALT + DEL\nMCU waits 1 second\nKeystrokes: <my username>\nKeystrokes: TAB\nKeystrokes: <my password>\nKeystrokes: ENTER\n[Windows displays welcome screen]<\/code><\/pre>\n\n\n\n
A bit of backstory: <\/em><\/p>\n\n\n\n
Our system admins enforced a very strict password policy. Passwords had to be very<\/em> complex and changed frequently. I followed the rules for a while but grew tired of typing long, strong passwords several times a day.<\/p>\n\n\n\n
That\u2019s when keyboard emulation came to my rescue \u2014 and life hasn\u2019t been the same since. \ud83d\ude0a<\/p>\n\n\n\n
What Do We Need?<\/strong><\/h2>\n\n\n\n
To build a simple keyboard emulator, you\u2019ll need:<\/p>\n\n\n\n