Gearotons M17 Servomotor

Name: Gearotons M17 Servomotor
Author: gearotons

@gearotonsMCP server · External

Drive Gearotons M17 open-source servomotors from plain English over RS-485; mock mode, no hardware.

Hardware & electronicsv0.3.3MITPython

Freeno charge per call

How to install

Runs on your machine from its package; the steps are below.

Claude Code driving a real Gearotons M17 over MCP: find the motor, turn it two rotations, back, read the encoder — From the README

What it does

Reads
Writes
High impact

At most: moves money, runs code or commands, deletes data, or sends messages for you.

What it costs

Free

Odel charges nothing per call. The publisher may charge for its own service.

Runs locally over stdio

This server isn't hosted — your MCP client launches it from a package registry. Use one of the commands below, or drop the config into your client (e.g. Claude Desktop).

PyPIservomotor-mcpv0.3.3

Run

uvx servomotor-mcp

MCP client config

{
  "mcpServers": {
    "gearotons-m17-servomotor": {
      "command": "uvx",
      "args": [
        "servomotor-mcp"
      ]
    }
  }
}

README5 min readView on GitHub

servomotor-mcp

Drive open-source Gearotons M17 servomotors from natural language.

An MCP server that exposes the M17 — a NEMA-17 integrated, closed-loop, RS-485 servomotor — to Claude Desktop, Claude Code, or any MCP client. Control real motors by just asking:

"Find my motors and rotate the one on the bench two full turns, slowly."

Nothing is hardcoded: the server discovers your serial ports, auto-detects the motors on the bus (the firmware's "Detect devices" command), and exposes the entire firmware command set — every command in the servomotor library's catalog becomes an MCP tool automatically (48 commands as of library 0.10.0), plus a few high-level tools for everyday moves. It ships with a mock backend, so you can try the whole thing with no hardware.

Claude Code driving a real Gearotons M17 over MCP: find the motor, turn it two rotations, back, read the encoder

▶ 50-second video: the real motor and this session side by side — recorded 2026-09-09 on a bench M17; every line above is from the session log.

Step-by-step tutorial (boxed motor to "talk to it" in about twenty minutes): Talk to a servomotor from Claude Code on Hackster.

The first servomotor with an official MCP server. Open hardware, open firmware, open software — and now an open, AI-native control interface.

Quickstart (no hardware, ~2 minutes)

bash

# Run the server directly with uv (recommended). This runs the SIMULATOR —
# for real motors see "Drive real motors" below:
uvx --from servomotor-mcp servomotor-mcp

# or install it:
pip install servomotor-mcp
servomotor-mcp

Then add it to Claude Desktop — copy the block from examples/claude_desktop_config.json into your claude_desktop_config.json, restart Claude Desktop, and ask: "What serial ports do you see? Connect and find my motors." See examples/demo_prompts.md for a scripted demo.

Drive real motors

Plug an M17 (or a daisy-chain of them) into a USB↔RS-485 adapter and install the [serial] extra — that's it, no configuration:

bash

pip install 'servomotor-mcp[serial]'   # pulls in the Gearotons servomotor library
servomotor-mcp

With the servomotor library installed the server uses the real serial backend automatically. Without it, the server runs its simulator and says so: list_serial_ports and connect return a notice field, and a warning goes to stderr. With uv, use uvx --from 'servomotor-mcp[serial]' servomotor-mcp. In a session, the model then:

list_serial_ports — enumerates the machine's ports (macOS /dev/cu.*, Windows COM*, Linux /dev/ttyUSB*), flagging USB serial adapters;
connect — opens the port you (or it) picked, at 230400 baud;
auto-detects every motor on that bus (unique ID + alias) — no address maps to write;
drives them. Tell it in plain English which adapter to use if you have several.

Tools

High-level (discovery + everyday motion):

Tool	What it does
`list_serial_ports`	Enumerate serial ports with USB metadata (call first).
`connect` / `disconnect`	Open a port and auto-detect the motors on that bus.
`detect_devices`	Re-scan the bus (reboots the motors on it).
`list_motors`	Detected motors with live position/voltage/temperature/status.
`move_to` / `move_relative`	Absolute / relative moves in degrees; waits for completion.
`stop`	Emergency-stop one or all motors.
`get_motor_status`	One motor's snapshot, fatal errors decoded to plain English.
`run_sequence`	Choreographed steps ("draw a square"), incl. raw command steps.

Plus one tool per firmware command, generated from the library's command catalog: enable_mosfets, go_to_position, move_with_velocity, move_with_acceleration, multimove, homing, zero_position, get_position, get_temperature, set_device_alias, set_pid_constants, system_reset, vibrate, ping, … — anything the motor can do, the model can do. Motors are addressed by their alias number, their 16-hex-digit unique ID, or "all" (broadcast). Values are in friendly units (degrees, seconds, degrees/s, volts, °C); the server converts to firmware units.

How it works

natural language → Claude → MCP tool calls → this server → RS-485 → M17 motors

The server is a thin layer over the Gearotons servomotor Python library. The library is data-driven — motor_commands.json defines every firmware command — and the server turns that same catalog into MCP tools, so new library commands appear automatically. Tool calls are forwarded straight to the hardware — no software clamping; full multi-turn travel, any speed. The motor's own firmware protections (over-current / over-voltage / over-temperature) still apply. The same tools run against the mock backend (GEAROTONS_MOTOR_BACKEND=mock) for development and CI.

Environment variables (all optional):

GEAROTONS_MOTOR_BACKEND — auto (default: serial when the servomotor library is installed, else mock), serial, or mock.
GEAROTONS_SERIAL_PORT — default port for connect when the model doesn't pass one.
GEAROTONS_DEFAULT_SPEED_DPS — default speed for move_to/move_relative (180).

Develop / test

bash

pip install -e '.[dev]'
GEAROTONS_MOTOR_BACKEND=mock pytest     # catalog + mock-bus + server-tool tests

hardware_tests/ contains scripts that exercise the real serial path end to end (port sweep, full command suite, stdio MCP session) against a bench motor.

Status

✅ Full firmware command surface (48 commands), serial-port discovery, bus auto-detection — verified on a physical M17 (fw 0.15.3.0) over a real stdio MCP session and via uvx, on all four test adapters (motor found only where it truly is).
✅ Mock backend + 39 unit tests, no hardware needed.
✅ Cross-platform port handling (macOS / Windows / Linux) via pyserial enumeration.

License

MIT. Hardware, firmware, and software for the M17 are open-source — see github.com/tomrodinger/servomotor.

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