Ryan Malloy
b16c20c2ca
CE amplifier schematic: the input coupling cap CC_in was placed horizontally (R90) at y=336 — the same y as the RB1-to-base bias wire. Both cap pins sat on the wire, shorting the cap and allowing Vin's 0V DC to override the bias divider, putting Q1 in cutoff. Fix: move CC_in to vertical orientation (R0) above the base wire. Now pinA=(400,256) and pinB=(400,320) are off the y=336 bias path. The cap properly blocks DC while passing the 1kHz input signal. Result: V(out) swings 2.2Vpp (gain ≈ 110) instead of stuck at Vcc. Colpitts oscillator test: the schematic was actually working (V(out) pp=2.05V) but the test's fallback variable selection picked V(n001) (the Vcc rail, constant 12V) instead of V(out). Fix: look for V(out) first since the schematic labels the collector with "out". Integration tests: 4/4 pass, unit tests: 360/360 pass.
mcp-ltspice
MCP server for LTspice circuit simulation automation on Linux.
Features
- Run Simulations - Execute .asc schematics or .cir netlists in batch mode
- Extract Waveforms - Parse binary .raw files to get voltage/current data
- Modify Schematics - Programmatically edit component values
- Browse Libraries - Access 6500+ symbols and 4000+ example circuits
Requirements
- Linux with Wine installed
- LTspice extracted (see below)
- Python 3.11+
Installation
# From PyPI (once published)
uvx mcp-ltspice
# From source
uv pip install -e .
LTspice Setup
Extract LTspice from the Windows MSI installer:
# Download LTspice64.msi from analog.com
cd /path/to/downloads
7z x LTspice64.msi -oltspice
cd ltspice
7z x disk1.cab
# Set up Wine prefix
export WINEPREFIX=$PWD/.wine
export WINEARCH=win64
wineboot --init
Set the LTSPICE_DIR environment variable or use the default ~/claude/ltspice/extracted/ltspice.
MCP Tools
| Tool | Description |
|---|---|
simulate |
Run simulation on .asc schematic |
simulate_netlist |
Run simulation on .cir netlist |
get_waveform |
Extract signal data from .raw file |
read_schematic |
Parse schematic components and nets |
edit_component |
Modify component values |
list_symbols |
Browse component symbol library |
list_examples |
Browse example circuits |
get_symbol_info |
Get symbol pins and attributes |
check_installation |
Verify LTspice setup |
MCP Resources
ltspice://symbols- All available component symbolsltspice://examples- All example circuitsltspice://status- Installation status
Usage with Claude Code
claude mcp add mcp-ltspice -- uvx mcp-ltspice
Or for local development:
claude mcp add mcp-ltspice -- uv run --directory /path/to/mcp-ltspice mcp-ltspice
License
MIT