Project Hub /IoT & Connected Devices/Telemetry & Remote Logging/Use Push Button as a Secure Login Key

Intermediate

INDUSBOARD

Project Specific

3 – 6 Hours

Partial Kit

Use Push Button as a Secure Login Key

This project uses an Indusboard dev board and a push button as a physical hardware login key to automatically type a password and unlock a laptop.

Originally published on ElectronicsForU

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
2-Slot 18650 Holder with Protective Cover and On/Off Switch – Case Rs. 109.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

We don't carry yet: Other Dev Board (Indusboard / Maixduino / misc)
Thyristor / SCR / Triac / Varistor / Fuse

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How It Works

This project transforms the compact IndusBoard Coin development board into a hardware-based authentication token capable of automating login sequences. The system relies on the board's native USB Human Interface Device (HID) keyboard support, which is programmed using the Arduino IDE. A physical push button is wired to the IndusBoard Coin using jumper wires, serving as the user input trigger. When you press the button, the microcontroller detects the state change on its General Purpose Input/Output (GPIO) pin. Upon registering this physical press, the IndusBoard executes a pre-compiled software routine that simulates a USB keyboard device. It automatically streams a sequence of predefined keystrokes—representing your password—across the USB Type C cable directly to the connected laptop. Because the laptop recognizes the IndusBoard Coin as a standard USB keyboard rather than a microcontroller, it processes the incoming data as legitimate keystrokes, populating the open login screen and unlocking the operating system without manual typing.

Why Build This

Implement physical token-based hardware authentication to protect workstations against visual password snooping in shared engineering labs.

Gain practical experience with USB Human Interface Device (HID) protocol emulation using microcontroller firmware.

Automate repetitive credential entry tasks safely using a dedicated, standalone hardware trigger.

Real-World Application

Providing quick and secure physical token-based authentication to unlock computers or systems, preventing password snooping in public spaces.

Skills You'll Learn

USB HID protocol implementation

GPIO digital input configuration

hardware debouncing principles

firmware-based keystroke automation

physical security token design

Safety Precautions

No specific precautions noted for this build — always follow general electronics safety practices.

Technology Tags

INDUSBOARD

USB HID

KEYBOARD EMULATION

MICROCONTROLLERS

SECURITY

HARDWARE KEY

Frequently Asked Questions

Can the IndusBoard Coin store my password securely?

Yes, the password string is hardcoded directly into the firmware compiled onto the microcontroller, meaning it is not exposed as a plain-text file on your computer's hard drive.

Will this device work on any computer?

It will work on any laptop or desktop that accepts a standard USB keyboard and has an active login prompt ready to receive text input.

What happens if I press the button accidentally while typing something else?

Because the IndusBoard Coin immediately streams keystrokes over the USB Type C connection, an accidental press will output the password wherever your computer's active text cursor is currently placed.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

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