⚠️ This repository was originally created by @baileyherbert and is no longer maintained. It has been moved here for preservation. The code within it might be outdated or broken.

MettlerMate

Introduction

This is a simple filter driver that makes Mettler Toledo BC60 scales work with PostalMate. It's also a great template for an HID USB filter driver that intercepts and modifies read reports, descriptors, and more.

The Mettler Toledo BC60 series is supposed to be fully backwards compatible with the PS60. However, a small programming error in PostalMate prevents the software from reading the correct weight in lb-oz unit mode. This driver intercepts and converts the data as it flows from the USB to the software.

Installation

Preparation

• Disable driver signature enforcement
• Download the repository and open the solution file.

Building

• Build the driver in debug mode with arch set to x64.
• Locate the built driver files (cat, inf, and sys extensions).

Driver installation

• On the target machine, right click the INF file and choose "install".
• Open device manager and right click the "HID-compliant weighing device" under Human Interface Devices. Choose "update driver".
• Choose "browse my computer" and "let me pick from a list of available drivers".
• Locate the MettlerMate driver in the list and select it.

You may be prompted to restart the machine the first time you load the driver.

Customization

It's simple to customize this driver for your own device. First edit the MettlerMate.inf file to replace the hardware ID on line 33 with the HID\ identifier for your particular device. This is required otherwise you will not be able to install the driver from device manager. You can optionally change the device name to anything you want.

Then edit the driver.h file and change the _WEIGHT_REPORT struct to match the data structure that your device sends.

Finally edit the driver.c file according to the following:

• Use the FilterEvtIoDeviceControl function to edit report descriptors. This is necessary if you're going to change the size (in bytes) of data. Microsoft has some example code to help start on this.

• Use the FilterRequestCompletionRoutine function to view read report buffers in transit from the device to userland.

• Use the ConvertWeightBuffer function to edit read report buffers to fit your needs.