logic-analyzer-mcp

AI-driven USB logic analyzer control via FastMCP 3.2. Capture digital traces with sigrok or the built-in simulator, decode UART/I2C/SPI, and export VCD for PulseView.

How it runs

Mode	Hardware	When
Simulator (default)	None	Development, CI, agent dry-runs
sigrok	Hantek 6022BL (LA mode), DSLogic, FX2 clones	Production bench with sigrok-cli

The MCP server does not bundle sigrok. Install PulseView or sigrok-cli separately, then connect your USB LA.

Hands-in / Hands-out

Direction	Artifacts	Notes
Hands-in	device_id, channels, trigger	Via la_device, la_configure, la_trigger
Hands-out	Trace preview (downsampled JSON)	la_capture(operation="single")
Hands-out	CSV, VCD, JSON summary	la_capture(operation="export_vcd") in LOGIC_ANALYZER_MCP_CAPTURE_DIR
Hands-out	Protocol decode rows	la_decode(operation="uart")

Fleet pipelines

Partner MCP	Workflow
oscilloscope-mcp	Mixed-signal bring-up (analog + digital)
kicad-mcp	Verify SPI/I2C after PCB bring-up
chip-design-mcp	Debug FPGA/MCU buses

Quick Start

Set-Location D:\Dev\repos\logic-analyzer-mcp
uv sync --extra dev
just webapp
# Open http://127.0.0.1:10987

STDIO-only (Cursor MCP):

just serve

Dry-run without hardware:

la_device(operation="connect", device_id="sim-la-001")
la_capture(operation="single", sample_rate_hz=1000000, sample_count=4096)
la_decode(operation="uart", rx="D0")

Cursor MCP config

Add to C:\Users\sandr\.cursor\mcp.json:

"logic-analyzer-mcp": {
  "command": "C:/Users/sandr/.local/bin/uv.exe",
  "args": [
    "--directory",
    "D:/Dev/repos/logic-analyzer-mcp",
    "run",
    "python",
    "-m",
    "logic_analyzer_mcp",
    "--stdio"
  ],
  "env": {
    "FASTMCP_BANNER": "0",
    "FASTMCP_UPDATE_CHECK": "0",
    "PYTHONUNBUFFERED": "1",
    "LOGIC_ANALYZER_MCP_BACKEND": "auto"
  }
}

Restart Cursor after editing mcp.json.

Tools

Tool	Operations
la_device	list, connect, disconnect, status, capabilities, backends
la_configure	channels, sample_rate, get, simulator_pattern
la_trigger	set, get
la_capture	single, preview, export_csv, export_vcd, export_summary, last
la_decode	list, run, last, uart, i2c, spi
la_help	discover, tool_help, status, quickstart, faq, hardware_guide

Webapp

Port	Role
10985	Backend (FastAPI + MCP /mcp)
10987	Frontend (Vite React — trace + decode viewers)

just webapp

Documentation

• INSTALL.md — setup paths
• docs/ARCHITECTURE.md — system design
• docs/TOOLS.md — portmanteau reference
• docs/HARDWARE.md — LA buying guide
• docs/BACKENDS.md — sigrok + simulator
• llms.txt — agent discovery index

License

MIT — see LICENSE.