white_led_ONLABSCO SUMMARY
The shortest path from a chat message to something physical happening.
Three tools and two LEDs is the entire scope, and it is written as a teaching project — but it is a complete, working chain from an MCP client to hardware, with the standard Firmata sketch doing the board-side work so nothing has to be flashed twice. The port path in main.py is the one place everyone gets stuck; change it before you run anything.
What it is
A small, deliberately concrete MCP server: an assistant says "turn on the white LED" and a physical LED on your desk lights up. It talks to the board through pyfirmata2 over the Firmata protocol, so the Arduino runs a stock sketch rather than custom firmware, and the tools are three functions defined with FastMCP.
What you get
- The white LED on digital pin 12 switched on —
white_led_ON - The red LED on digital pin 11 switched on —
red_led_ON - Both switched off —
led_OFF - A pattern you can extend: the tools are plain Python functions marked with a decorator, so adding a pin or a behaviour is adding a function
Requirements
An Arduino board, two LEDs with resistors, jumper wires and a USB cable. Upload the StandardFirmata sketch from the Arduino IDE's Firmata examples first — that is what lets Python drive the board. Python 3.12 or higher and uv, which installs fastmcp and pyfirmata2 from the project file. The one edit you must make is the serial port in main.py: replace the sample device path with the port your board is on, which the Arduino IDE shows under Tools > Port and which looks like COM3 on Windows or /dev/ttyUSB0 on Linux.
Setup effort
Build from source — git clone https://github.com/AimanMadan/Arduino_MCP_Server.git
USE CASES
01
Seeing an AI change something in the physical world
Ask for the white or the red LED and watch the board respond — the shortest demonstration of a model driving hardware.
02
Learning how an MCP tool is actually defined
Read the three decorated functions in main.py, which is the whole server, before writing your own.
03
Extending it to your own circuit
Add a function for the pin you wired and mark it as a tool; the Firmata connection already covers the board side.
3 tools
Listed in project docs. Your client may show a different list.
red_led_ONled_OFFBEFORE YOU INSTALL
What to know first
Tools you get
3 tools named in the project's documentation.
Requires
- uv on PATH
- Python 3.12 or later
Where it runs
The documented client runs the server on your machine.
INSTALLATION
Connect your client
You clone this one yourself.
Server setup
TERMINAL
git clone https://github.com/AimanMadan/Arduino_MCP_Server.git
cd Arduino_MCP_ServerMCP Clients
Claude Desktop
CLAUDE DESKTOP · JSON
{
"mcpServers": {
"arduino": {
"command": "uv",
"args": [
"--directory",
"<YOUR_ARDUINO_MCP_SERVER_FOLDER>",
"run",
"main.py"
]
}
}
}
