Using MRGui on Mac OSX

MRGui is our configuration utility for MRBus based devices.  It simplifies the process of setting the various EEPROM configuration options for each node, using a user-friendly GUI that runs on Windows, Mac, or Linux.  In addition to setting EEPROM configuration options, MRGui can also be used for general purpose programming of AVR microcontrollers.  The instructions below take you through the steps to get up and running with MRGui on the Mac OSX platform.

Step 1 – Obtain a Programmer

Before configuring or reprogramming the firmware in an MRBus device, an AVR programmer is required.  Some products, such as the Interlocking-In-A-Box, come standard with a programmer.  For others, you will need to purchase a compatible programmer.  The ISE AVR Programmer is our recommended programmer, because of its low cost and ease of use, and this guide is written assuming you are using that one.  For advanced users who choose to use a different programmer, it is assumed you will know which options to select later on in the guide.

Step 2 – Download MRGui

The latest MRGui release can be found on GitHub.  For OSX, download the latest mrgui-osx.dmg release.  Once downloaded, open the DMG disk image file.  The MRGui application icon should appear.  Double clicking the icon should start the application, but you may get a warning about the application being from an unidentified developer.


To get around this, right-click the MRGui icon and select Open.


The same dialog window will again appear, but this time with an Open button.  Click the Open button and the MRGui application should start.

At this point you are ready to use MRGui to configure your device!


Q: What do I do if I get a “Could not find USBtiny device” error message when reading from or writing to a device?


A: First, check that the programmer is plugged into the computer’s USB port.  If so, make sure that the correct programmer is selected.   Try unplugging and re-plugging the programmer.  If none of these resolve the problem, then contact us, including as much information as possible (screenshots are always helpful).

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