3.a. Installing Windows Drivers and Software

If you are using Windows XP, you will need to have Service Pack 3 installed before installing the drivers for the Maestro. See below for details.

Before you connect your Maestro to a computer running Microsoft Windows, you should install its drivers:

1. Download the Maestro Servo Controller Windows Drivers and Software (5MB zip)
2. Open the ZIP archive and run setup.exe. The installer will guide you through the steps required to install the Maestro Control Center, the Maestro command-line utility (UscCmd), and the Maestro drivers on your computer. If the installer fails, you may have to extract all the files to a temporary directory, right click setup.exe, and select “Run as administrator”.
3. During the installation, Windows will ask you if you want to install the drivers. Click “Install” (Windows 7, 8, and Vista) or “Continue Anyway” (Windows XP).

4. After the installation is finished, your start menu should have a shortcut to the Maestro Control Center (in the Pololu folder). This is a Windows application that allows you to configure, control, debug, and get real-time feedback from the Maestro. There will also be a command-line utility called UscCmd which you can run at a Command Prompt.

Windows 8, Windows 7, and Windows Vista users: Your computer should now automatically install the necessary drivers when you connect a Maestro. No further action from you is required.

Windows XP users: Follow steps 5–9 for each new Maestro you connect to your computer.

5. Connect the device to your computer’s USB port. The Maestro shows up as three devices in one so your XP computer will detect all three of those new devices and display the “Found New Hardware Wizard” three times. Each time the “Found New Hardware Wizard” pops up, follow steps 6-9.
6. When the “Found New Hardware Wizard” is displayed, select “No, not this time” and click “Next”.

7. On the second screen of the “Found New Hardware Wizard”, select “Install the software automatically” and click “Next”.

8. Windows XP will warn you again that the driver has not been tested by Microsoft and recommend that you stop the installation. Click “Continue Anyway”.

9. When you have finished the “Found New Hardware Wizard”, click “Finish”. After that, another wizard will pop up. You will see a total of three wizards when plugging in the Maestro. Follow steps 6-9 for each wizard.

If you use Windows XP and experience problems installing or using the serial port drivers, the cause of your problems might be a bug in older versions of Microsoft’s usb-to-serial driver usbser.sys. Versions of this driver prior to version 5.1.2600.2930 will not work with the Maestro. You can check what version of this driver you have by looking in the “Details” tab of the “Properties” window for usbser.sys in C:\Windows\System32\drivers. To get the fixed version of the driver, you will need to install Service Pack 3. If you do not want Service Pack 3, you can try installing Hotfix KB918365 instead, but some users have had problems with the hotfix that were resolved by upgrading to Service Pack 3. The configuration software will work even if the serial port drivers are not installed properly.

After installing the drivers, if you go to your computer’s Device Manager and expand the “Ports (COM & LPT)” list, you should see two COM ports: the Command Port and the TTL Port. In parentheses after these names, you will see the name of the port (e.g. “COM5” or “COM6”). If you expand the “Pololu USB Devices” list you should see an entry for the Maestro.

Windows 7 device manager showing the Micro Maestro 6-channel USB servo controller.

Windows XP device manager showing the Micro Maestro 6-channel USB servo controller.

Some software will not allow connection to higher COM port numbers. If you need to change the COM port number assigned to your USB device, you can do so using the Device Manager. Bring up the properties dialog for the COM port and click the “Advanced…” button in the “Port Settings” tab. From this dialog you can change the COM port assigned to your device.