AI Multisim Automation Agent

An intelligent automation tool that generates SPICE netlists using Google's Gemini AI and automatically imports and runs them in NI Multisim.

Overview

This Python script bridges the gap between natural language circuit descriptions and executable circuit simulations. Simply describe your circuit design in plain English, and the AI agent will:

1. Generate a proper SPICE netlist using Gemini 2.5 Pro
2. Launch NI Multisim with the generated circuit
3. Automatically run the simulation

Features

• AI-Powered Netlist Generation: Leverages Google Gemini 2.5 Pro to create accurate SPICE netlists from text descriptions
• Automatic Multisim Integration: Seamlessly launches and controls Multisim
• Robust Error Handling: Includes retry logic for API calls and detailed error messages
• Zero Manual Intervention: From prompt to simulation with a single command

Prerequisites

Software Requirements

• Python 3.7+
• NI Multisim 14.3 (Circuit Design Suite)
• Windows OS (required for pywinauto automation)

Python Dependencies

pip install google-genai pywinauto python-dotenv

Installation

1. Clone or download this repository

2. Install required Python packages:

   pip install google-genai pywinauto python-dotenv
   

3. Set up your Gemini API key:

   • Obtain an API key from Google AI Studio
   • Create a .env file in the project directory:

     GEMINI_API_KEY=your_api_key_here
     

4. Verify Multisim installation path:

   • Default path: C:\Program Files (x86)\National Instruments\Circuit Design Suite 14.3\multisim.exe
   • If your installation differs, update the MULTISIM_EXE variable in the script

Usage

1. Run the script:

   python multisim_ai_agent.py
   

2. Enter your circuit design prompt when prompted:

   Enter your circuit design prompt: Design a simple RC low-pass filter with 1kHz cutoff frequency
   

3. Wait for the automation to complete:

   • The AI generates the netlist
   • Multisim launches automatically
   • The simulation runs (F5 is triggered)

Example Prompts

• "Create a voltage divider circuit with two 10k resistors and a 12V source"
• "Design a simple RC low-pass filter with 1kHz cutoff frequency"
• "Build a BJT common emitter amplifier with proper biasing"
• "Create a full-wave bridge rectifier with smoothing capacitor"

Configuration

Customizable Variables

MULTISIM_EXE = r"C:\Program Files (x86)\National Instruments\Circuit Design Suite 14.3\multisim.exe"
NETLIST_FILE = "ai_generated_circuit.cir"
MULTISIM_WINDOW_TITLE = "Multisim"

Timeout Settings

Adjust these in the automate_multisim_import_and_run() function if needed:

• window_find_timeout: Time to wait for Multisim window (default: 20s)
• Initial launch delay: 10 seconds

How It Works

1. AI Netlist Generation

The script connects to Google's Gemini 2.5 Pro API with a specialized system prompt that ensures:

• Pure SPICE netlist output (no markdown formatting)
• Proper analysis commands (.AC, .TRAN, .OP)
• Standard SPICE conventions
• Correct component models

2. Multisim Automation

Uses pywinauto to:

• Launch Multisim with the netlist file as a command-line argument
• Connect to the application window
• Send F5 keystroke to run the simulation

3. Error Handling

• Automatic retries for API 503 errors (with exponential backoff)
• Comprehensive error messages
• Empty response validation

Troubleshooting

Common Issues

"GEMINI_API_KEY environment variable not set"

• Ensure your .env file exists in the script directory
• Verify the API key is correct and has no extra spaces

"Multisim Automation Failed"

• Check that Multisim is properly installed
• Verify the executable path matches your installation
• Close any existing Multisim instances before running
• Disable startup dialogs in Multisim settings

Simulation doesn't run automatically

• The script waits 10 seconds after launch; increase this if your system is slow
• Ensure no dialog boxes are blocking the main window
• Check if F5 is the correct shortcut in your Multisim version

API Connection Issues

• Verify your internet connection
• Check if the Gemini API is experiencing downtime
• Ensure your API key has not expired

Limitations

• Currently supports Windows only (due to pywinauto)
• Requires NI Multisim to be installed
• Netlist quality depends on AI interpretation
• Complex circuits may require manual refinement

Security Notes

• Keep your .env file private and never commit it to version control
• Add .env to your .gitignore file
• Rotate your API keys periodically

License

This project is provided as-is for educational and research purposes.

Contributing

Suggestions and improvements are welcome! Consider:

• Support for other SPICE simulators
• Enhanced error detection
• Circuit validation before simulation
• Results extraction and analysis

Acknowledgments

• Google Gemini AI for netlist generation
• NI Multisim for circuit simulation
• pywinauto for Windows automation

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Note: This tool is designed to accelerate circuit prototyping and learning. Always verify AI-generated circuits before use in production environments.