logic-mcp

Vendor-neutral MCP server for logic analyzers. Cursor (or any MCP client) can capture from hardware, open a trace file, decode a bus, and reconstruct a display framebuffer.

DreamSourceLab / DSView, Saleae, and VCD are plugins, not the product name.

Cursor ── stdio MCP ── logic-mcp
                         ├─ in-process: mock / sigrok_cli / dslogic
                         └─ ipc / dsview ── Unix socket ── vendor process
                              └─ LogicCapture → bus decode → DCS log / PNG

What it does

• Live instrument control — scan, configure, start/stop/wait, export.

• Offline files — open a capture (DSView CSV today; Saleae CSV / VCD are stubs).

• Bus decode — Intel 8080 / MCU 8080 parallel is implemented; SPI, I2C, UART are stubs with roles reserved.

• Upper decode — MIPI DCS / ST7789 command log + optional PNG reconstruction.

Vendors attach in either way:

1. In-process — Python InstrumentBackend registered on logic_mcp.instruments.

2. IPC — a long-lived process speaking logic_mcp.instrument.v1 on a Unix socket (patched DSView, or the reference hub logic-mcp-instrument).

MCP tool names stay vendor-neutral. Do not add dsview_set_rate-style tools.

Related MCP server: mcp-sigrok

Status

Requirements

• Python 3.11+

• uv (recommended) or pip

• Optional: sigrok-cli on PATH (or SIGROK_CLI) for live sigrok_cli / dslogic

• Optional: DSView rebuilt with the patch in vendor/dsview (listens on $XDG_RUNTIME_DIR/logic-mcp/dsview.sock)

Install

git clone https://github.com/dengtaowei/logic-mcp.git
cd logic-mcp
uv sync --extra dev
uv run pytest

Cursor MCP

Add to Cursor MCP settings. Point --directory at your clone:

{
  "mcpServers": {
    "logic": {
      "command": "uv",
      "args": ["--directory", "/path/to/logic-mcp", "run", "logic-mcp"]
    }
  }
}

The server speaks MCP over stdio. It returns JSON summaries, not raw sample dumps.

Then open Agent chat and talk to the model; you do not run decode scripts. First session (ST7789 over 8080): examples/README.md.

Workflows

Offline CSV

capture_open(path) → bus_decode(protocol, channel_map)
                  → display_analyze          # command log
                  → display_reconstruct      # command log + PNG

channel_map is required. Values are CSV column names or 0-based indices. A DSView export named RS,CS,RD,WR,DB0…DB7 maps like examples/channel_maps/i8080_dsview.json (dc → RS, not CS).

PNGs land under out/ (or LOGIC_MCP_OUT).

Full config in MCP (mock / sigrok)

instrument_open(backend) → instrument_configure → instrument_capture
→ bus_decode → interpret

CaptureRequest fields: sample_rate_hz, channels, duration_s xor sample_count, optional trigger, extra. There is no channel_count; pass the channel name list.

Config in the vendor GUI (DSView)

Human sets rate, channels, and trigger in DSView. MCP only arms:

instrument_open("dsview") → instrument_start → instrument_wait → instrument_export

hello.configure=false means the GUI owns sample rate and channels. instrument_capture without sample_rate_hz is valid on those backends.

Instrument backends

Reference hub (wraps an in-process backend behind the socket):

uv run logic-mcp-instrument --socket "$XDG_RUNTIME_DIR/logic-mcp/instrument.sock"
# optional: --backend mock --gui-owned

IPC methods, framing, and states: src/logic_mcp/instrument/PROTOCOL.md.

MCP tools

Inventory: protocol_list, session_status.

Instrument: instrument_list, instrument_scan, instrument_open, instrument_close, instrument_capabilities, instrument_configure, instrument_capture, instrument_start, instrument_stop, instrument_wait, instrument_export.

Decode: capture_open, protocol_roles, bus_decode, interpret, display_analyze, display_reconstruct.

Extending

Entry points in pyproject.toml:

Out of process: listen on the Unix socket and implement hello / status / start / stop / wait / export (and configure / capabilities if you own config). Python reference: logic-mcp-instrument.

When a vendor’s own GUI/SDK must be patched, put a unified diff under vendor/<id>/ (pinned upstream commit + series). Do not copy their whole tree. First example: vendor/dsview.

Panel YAML (profiles/st7789.yaml, or LOGIC_MCP_PROFILES): width, height, offsets, extra DCS opcodes.

Environment

License

MIT for logic-mcp.

Patches under vendor/ are against other projects and keep that project’s license. vendor/dsview is GPLv3+ (DreamSourceLab DSView).