We will be attending Prototype Rails on January 6-8, 2022, in Cocoa Beach, FL. If you’re in the area, or already planning to attend, please take in some great clinics and stop by our tables and say hi. Hope to see you there! Note: Shipping of orders received Jan 5-17 may be delayed. Normal operations should resume Jan 18.

ProtoThrottle Firmware Update Instructions

The following instructions can be used to update the firmware on your ProtoThrottle.  They can also be used to update your ProtoThrottle Receiver for NCE Cab Bus and Lenz XpressNet.

  1. Download the appropriate .hex file to your computer.  Be sure to download the file for the device you are updating (putting ProtoThrottle firmware on your Cab Bus receiver won't work, nor vice versa).  The latest .hex files can be found on the product pages of the respective products, in the Firmware section:
    ProtoThrottle (MRBW-CST)
    ProtoThrottle Receiver for NCE Cab Bus and Lenz XpressNet (MRBW-CABBUS)

  2. Attach the ribbon cable from the programmer to the 6-prong male receiver on the printed circuit board. Make sure the triangle shape on the ribbon cable’s female connector matches with the white arrow on the male receiver.

  3. Attach the programmer to your computer using a mini USB cable.

  4. Install the MRGui application, if you haven't done so already.  MRGui is a graphical application that makes updating the firmware on your ProtoThrottle or Cab Bus/XpressNet receiver simple and easy.  To install, follow the directions in one of the articles below, based on the operating system you are using:
    Using MRGui on Windows
    Using MRGui on Mac OSX

    Note: If using Windows, be sure to complete the driver install (Step 3) in the instructions above.

  5. Open the MRGui application you installed above and the Select Node screen will appear.  Select the "Generic ATmega1284P" node:

  6. Next the main MRGui main screen will appear.  In the menu under “Program” choose “Update Firmware...”

  7.  Find the .hex file you downloaded in step 1 to initiate the update. The Console screen (below) will appear and show running progress.  Be on the lookout for any errors.  If successful, you should see the line "avrdude.exe: nnnn bytes of flash verified" where "nnnn" is some number, dependent on the file being uploaded - don't worry about the exact value.  If you see that message, your firmware is updated!