Communicating with IDTech Devices requires the following library to be referenced by the project:

IDTechSDK.dll

Add the reference as you would any .NET managed library reference. The most direct method would be right-click on the "References" in the Solution Explorer for the project, select "Add Reference...", click "Browse..." and locate IDTechSDK.dll.

IDTechSDK.dll has a dependency of Microsoft .NET 4.5 or greater. Please make sure your final application installer checks for this dependency and installs it if not on the destination system.

In addition, the following libraries need to be added to project folder and included in with the application distribution:

IDTechCommDll.dll
ssleay32.dll
libeay32.dll
L100_config.dll
L100_device.dll
L100_lcd.dll
L100_parse.dll
L100_pin.dll

You can add these libraries by right-clicking on your project name in the solution Explorer and select "Add->Existing Item..." or keyboard shortcut Shift-Alt-A.

Once all three items are added, set their properties to "Copy if newer" so they will be included in the final applications destination folder.