How to Set Up Virtual Serial COM Ports Using com0com

 Virtual serial COM ports are essential for testing and debugging serial communication between software applications. com0com is a free, open-source virtual serial port emulator that allows you to create pairs of virtual COM ports that communicate with each other. This step-by-step tutorial will guide you through downloading, installing, and configuring com0com to set up virtual COM ports.

Step 1: Download com0com

    1. Visit the official com0com project page on SourceForge or GitHub.
    2. Download the latest version of com0com for your operating system.

• Make sure to choose the correct version for your OS architecture (32-bit or 64-bit).

Step 2: Install com0com

    1. Extract the downloaded zip file to a folder on your computer.
    2. Open the extracted folder and locate the installer executable (setup_com0com_x64.exe for 64-bit systems or setup_com0com_x86.exe for 32-bit systems). setup_com0com_v3.0.0.0_W7_x64_signed.exe in my case.
    3. Right-click the installer and select Run as Administrator.
    4. Follow the installation wizard:

• Accept the license agreement.
• Choose the installation directory (default is recommended).
• Click Install to complete the process.

    5. After installation, you might see a driver installation prompt. Click Install or Allow to proceed with the virtual driver setup.

Step 3: Verify com0com Installation

    1. Open the Device Manager:

• Press Win + X and select Device Manager.

    2. Expand the Ports (COM & LPT) section.
Look for devices labeled like com0com - bus for serial port pair. This confirms that com0com has been successfully installed.

Step 4: Configure Virtual COM Ports

com0com creates pairs of virtual COM ports that are interconnected. For example, data sent to COM10 will be received by COM11 and vice versa.

Using the GUI Configuration Tool

1. During installation, com0com may have installed a GUI tool named Virtual Null Modem. Launch it from the Start menu or in the desktop icon.
• To create a new pair of virtual com ports click Add Pair button.
2. (Optional) Verify the added pair in Device Manager. (You can refer above Step 3: Verify com0com Installation).
3. Rename the port with your preferred port name.
4. Save the changes after renaming the ports by clicking Apply button.
5. (Optional) Verify whether the rename ports have been applied successfully.

Step 5: Test the Virtual COM Ports

1. Use any serial communication software (e.g., PuTTY, Tera Term, or HyperTerminal) to test the setup.
2. Open one instance of your terminal software and connect it to COM10.
3. Open another instance and connect it to COM11.
4. Send some data from one terminal. You should see the data appear on the other terminal, confirming successful communication between the virtual COM ports.

Using com0com to set up virtual serial COM ports is a simple yet powerful way to simulate and test serial communication between applications without requiring physical hardware. This method is invaluable for developers working on serial communication protocols, data logging, or hardware interfacing projects.