MATLAB variables to running python script

I can clarify better if need be, but essentially I am attempting to run a python script to control a gimble. I would like to continuosly feed variables from the MATLAB script, where the user is inputting values, into the python script without executing another pyrunfile command. I have done a lot of research, but cannot find a suitable solution to this. Any help is greatly appreciated.

Answer 1

[Shubham]

Hi John,

To continuously feed variables from a MATLAB script to a Python script without repeatedly executing the pyrunfile command, you can use inter-process communication (IPC) methods. One effective approach is to use a socket-based communication system or shared memory. Here, I'll outline a socket-based solution.

Steps to Achieve Continuous Communication:

1. Set Up a Python Server:

• The Python script will act as a server that listens for incoming connections from MATLAB.
• The server will continuously receive data from MATLAB and perform the necessary actions to control the gimbal.

2. Set Up a MATLAB Client:

• The MATLAB script will act as a client that connects to the Python server.
• The client will send user-input values to the Python server as they are updated.

Example Implementation:

Python Script:

import socket

def start_server(host='localhost', port=65432):
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.bind((host, port))
        s.listen()
        print(f"Server started at {host}:{port}")
        conn, addr = s.accept()
        with conn:
            print(f"Connected by {addr}")
            while True:
                data = conn.recv(1024)
                if not data:
                    break
                # Process the received data
                value = float(data.decode())
                print(f"Received value: {value}")
                # Add your gimbal control logic here

if __name__ == "__main__":
    start_server()
    

MATLAB Client Script:

% MATLAB script to send data to Python server

% Establish connection to the Python server
host = 'localhost';
port = 65432;
client = tcpclient(host, port);

% Function to send data to the Python server
function send_data_to_server(client, value)
    write(client, num2str(value), 'string');
end

% Example loop to continuously send user-input values
while true
    % Get user input (replace with your actual input method)
    value = input('Enter a value: ');
    
    % Send the value to the Python server
    send_data_to_server(client, value);
    
    % Pause for a short period to simulate continuous operation
    pause(0.1);
end

% Close the connection when done
clear client;

Explanation:

1. Python Server:

• The Python server script (server.py) creates a socket that listens on localhost and port 65432.
• It accepts a connection from a client (MATLAB script) and enters a loop to receive data continuously.
• The received data is processed (e.g., controlling the gimbal).

2. MATLAB Client:

• The MATLAB script establishes a connection to the Python server using the tcpclient function.
• It defines a function send_data_to_server to send user-input values to the Python server.
• In a loop, the script continuously prompts the user for input and sends the input values to the Python server.

Running the Scripts:

1. Start the Python Server:

• Open a terminal or command prompt and navigate to the directory containing server.py.
• Run the server script:

python server.py

2. Run the MATLAB Client:

• Open MATLAB and run the MATLAB script.

This setup allows continuous communication between MATLAB and Python, where MATLAB sends updated values to the Python server without repeatedly executing the pyrunfile command. The server processes the incoming data in real-time, enabling you to control the gimbal based on user input from MATLAB.