BrickAgent - Connecting Claude to your Mindstorms EV3 Robot

Use the following approach to team-up EV3 and Claude.

1. https://www.ev3dev.org - start your EV3 from SD card flashed with ev3dev Linux

2. Equip your EV3 with a wifi dongle to make it accessible in your WLAN

3. Clone the MCP server in this repo, adapt configuration

     # ─── Configuration ────────────────────────────────────────────────
     EV3_HOST = "robot IP"
     EV3_USER = "robot"
     EV3_PASS = "maker"          # Default ev3dev password
     
     WHEEL_DIAMETER_MM = 33.3    # Wheel diameter in mm (adjust if distance is off)
     AXLE_TRACK_MM     = 186     # Axle track in mm (adjust if turn angles are off)
   

4. Add the following to your claude_desktop_config.json to let Claude know about the MCP

    "mcpServers": {
         "ev3-robot": {
            "command": "<local-path>/ev3-env/bin/python",
            "args": ["<local-path>/ev3_mcp.py"]
    }
   

5. Verify Claude detects the MCP; need to restart Claude, then check in the chat input via clicking plus: ev3-robot should show up under Connectors.

6. Ask Claude to check the connection to your ev3

First fun thing to do is to ask the agent to let your robot "drive" letters on the floor and let you guess which one. But essentially you can now completely use the agentic planning capabilities of Claude for chaining operation to achieve ends. Sensors give you a feedback-loop.

Disclaimer: run custom script is potentially dangerous. Claude may decide to let your robot drive over your feet.

Notes

• ev3dev-browser may help debugging, you can connect via USB and ssh into the ev3 in VS Code if the WIFI setup fails for some reason
• for me, bluetooth failed as cable-less connection option as it seems in macOS Bluetooth PAN has been removed

Architecture

graph TB
    subgraph User["👤 User"]
        U[Natural Language Prompt]
    end

    subgraph Claude["🤖 Claude Desktop (Mac)"]
        CD[Claude AI]
        CFG["claude_desktop_config.json\n(mcpServers: ev3-robot)"]
    end

    subgraph MCP["🐍 MCP Server — ev3_mcp.py"]
        FM[FastMCP 'EV3 Mindstorms MCP']

        subgraph Tools["Registered Tools (@mcp.tool)"]
            T1[drive_forward]
            T2[drive_backward]
            T3[turn]
            T4[stop]
            T5[beep]
            T6[speak]
            T7[measure_ir_distance]
            T8[read_color]
            T9[control_single_motor]
            T10[test_connection]
            T11[run_custom_script]
        end

        subgraph SSH["SSH Helpers"]
            SH1["ssh_run()\nfor simple Python3 commands"]
            SH2["ssh_script()\nupload + pybricks-micropython"]
        end
    end

    subgraph Network["📡 Local WiFi (192.168.178.x)"]
        WIFI[SSH over TCP]
    end

    subgraph EV3["🤖 LEGO EV3 Brick (ev3dev Linux)"]
        PY3[Python 3 — system commands]
        PBM[pybricks-micropython — motor/sensor scripts]

        subgraph HW["Hardware"]
            MA[Motor Port B — left drive]
            MB[Motor Port C — right drive]
            SC[Color Sensor Port S3]
            SI[IR Sensor Port S4]
            SPK[Speaker / Beeper]
        end
    end

    U -->|types command| CD
    CFG -->|configures| CD
    CD <-->|MCP protocol stdio| FM
    FM --> Tools
    Tools --> SSH
    SH1 -->|SSH exec python3 -c| WIFI
    SH2 -->|SFTP upload + brickrun| WIFI
    WIFI -->|SSH| PY3
    WIFI -->|SSH + SFTP| PBM
    PBM --> HW
    PY3 --> HW
    HW -->|sensor readings| PBM
    PBM -->|stdout result| WIFI
    WIFI -->|response| SSH
    SSH -->|tool return value| FM
    FM -->|result| CD
    CD -->|answer| U

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