4.f. Upgrading Firmware

Please do not attempt to upgrade your Maestro’s firmware unless you know what you are doing. Most customers do not need to upgrade their firmware.

The firmware is the program that runs on the Maestro. The Maestro has field-upgradeable firmware that can be easily updated with bug fixes or new features. There are four types of Maestros: the Micro Maestro 6-Channel USB Servo Controller (usc02a), the Mini Maestro 12-Channel USB Servo Controller (usc03a), the Mini Maestro 18-Channel USB Servo Controller (usc03b), and the Mini Maestro 24-Channel USB Servo Controller (usc03c). Each type of Maestro has its own firmware and you cannot load the firmware for one type onto another.

Firmware Versions

• Firmware Version 1.00: This is the original version of the firmware.
• Firmware Version 1.01 for the Micro Maestro 6-Channel USB Servo Controller: This firmware version was released on 2009-11-19 for the Micro Maestro only. It contains a bug-fix that makes “Ignore” mode servos behave correctly at startup.
• Firmware Version 1.02: This firmware version was released on 2013-06-20 for all four types of Maestros. This firmware version fixes a problem where in some cases the position of a servo with an acceleration limit would never settle to the target value. This update also fixes some minor problems with error handling. For the Mini Maestros, this update also fixes the yellow LED to blink the same way that it does on the Micro Maestro.
• Firmware Version 1.03: This firmware version was released on 2016-05-06 for all four types of Maestros. This firmware version fixes an issue that prevented the Maestros from working on macOS 10.11 or later.
• Firmware Version 1.04 for the Micro Maestro 6-Channel USB Servo Controller: This firmware version was released on 2019-06-10 for the Micro Maestro only. It fixes a bug where receiving a serial command could potentially interfere with the Maestro’s servo update routine, causing position updates for some servos to happen too soon or to be skipped entirely. Repeated serial commands at high baud rates could also trap the Maestro in the servo update routine, causing it to become unresponsive. This bug does not affect the Mini Maestros.

Upgrade Instructions

You can determine the version of your Maestro’s firmware by running the Maestro Control Center, connecting to a Maestro, and looking at the firmware version number which is displayed in the upper left corner next to the “Connected to” drop-down box. If you do not already have the latest version (1.03 for Mini Maestros, 1.04 for the Micro Maestro), you can upgrade by following the instructions below:

1. Save the settings stored on your Maestro using the “Save settings file…” option in the File menu. All of your settings will be reset to default values during the firmware upgrade.
2. Determine which type of Maestro you have either by counting the number of channels or by looking at the name that appears in your Device Manager. There are four types of Maestro: the Micro Maestro 6-Channel USB Servo Controller (usc02a), the Mini Maestro 12-Channel USB Servo Controller (usc03a), the Mini Maestro 18-Channel USB Servo Controller (usc03b), and the Mini Maestro 24-Channel USB Servo Controller (usc03c).
3. Download the latest version of the firmware for your type of Maestro. It is important that you know which type of Maestro you have so that you can download the correct version. The latest firmware versions can be downloaded here:
   • Firmware version 1.04 for the Micro Maestro 6-Channel USB Servo Controller (usc02a) (34k pgm)
   • Firmware version 1.03 for the Mini Maestro 12-Channel USB Servo Controller (usc03a) (41k pgm)
   • Firmware version 1.03 for the Mini Maestro 18-Channel USB Servo Controller (usc03b) (42k pgm)
   • Firmware version 1.03 for the Mini Maestro 24-Channel USB Servo Controller (usc03c) (43k pgm)
4. Connect your Maestro to a Windows or Linux computer using a USB cable.
5. Run the Maestro Control Center and connect to the Maestro by selecting its serial number in the “Connected to:” drop-down box in the upper left corner.
6. If you were not able to connect to the Maestro using the Maestro Control Center, double-check your USB connection, make sure all other devices are disconnected from the Maestro, and try plugging it into several different USB ports on your computer. If you are still unable to connect to it, see the instructions in Section 4.f.1 for doing a hard bootloader reset.
7. Go to the Device menu and select “Upgrade firmware…”. You will see a message asking you if you are sure you want to proceed: click OK.
8. If you are using Windows XP and see a Found New Hardware Wizard window appear, then you should follow steps 6–8 from Section 3.a to get the bootloader’s driver working.
9. Once the Maestro is in bootloader mode and the bootloader’s drivers are properly installed, the green LED should be blinking in a double heart-beat pattern, and there should be an entry for the bootloader in the “Ports (COM & LPT)” list of your computer’s Device Manager.
10. Go to the window entitled “Firmware Upgrade” that the Maestro Control Center has opened.
11. Click the “Browse…” button and select the firmware file you downloaded. Make sure that the selected file is the right file for your type of Maestro (see steps 2 and 3).
12. Select the COM port corresponding to the bootloader. If you do not know which COM port to select, go to the Device Manager and look in the “Ports (COM & LPT)” section.
13. Click the “Program” button. You will see a message warning you that your device’s firmware is about to be erased and asking you if you are sure you want to proceed: click Yes.
14. It will take a few seconds to erase the Maestro’s existing firmware and load the new firmware. Do not disconnect the Maestro during the upgrade.
15. Once the upgrade is complete, the Firmware Upgrade window will close, the Maestro will disconnect from your computer, and it will reappear. If there is only one Maestro plugged in to your computer, the Maestro Control Center will connect to it. Check the firmware version number and make sure that it now indicates the latest version of the firmware.

If you have problems during or after the firmware upgrade, then it is possible that you loaded the wrong firmware onto your Maestro or some other problem corrupted the firmware. The solution is to retry the firmware upgrade procedure above. Even if your Maestro is not recognized at all by your computer and you see no sign of life from it, the instructions in step 6 and Section 4.f.1 can help you get the Maestro into bootloader mode. If you continue to have trouble after trying multiple times, please email us for assistance.