A dynamic link library for the U4x1 hides most of the messy interface commands. The DLL (USBm.dll) provides a function for EACH device operation. Visual Basic can access the DLL by including an interface file (USBmAPI.bas).
For example, to write E7h to port A use this command:
USBm_WritePortA( device, 0xE7 )
Encapsulation of USB Commands
The USBm.dll Dynamic Link Library for the USB interface devices captures many of the messier USB programming details. The DLL can be used with VB, C, Delphi, .NET or any appropriate Windows programming language. It is much easier and faster to use the USBmicro dynamic link library to control the USB devices than to use direct Windows API commands.
For Visual Basic the file USBmAPI.bas should be included in the project. This file has all of the declarations that support the functions in the DLL.
Use of DLL
The USBm.dll Dynamic Link Library can be used by any owner of a U401⁄U421⁄U451 without a license charge.
Use of MS VC++
Please see the VC++ interface section for using the USBm.dll Dynamic Link Library with Visual C++.
Current DLL version
The USBm.dll Dynamic Link Library current numerical version is 61.
Version 65 – support for firmware 3.35 (2-wire and latching)
Version 61 – support for U451.
Version 60 – stepper count.
Version 56 – strobe byte delay, servo.
Version 52 – library clean up.
Version 42 – support for strobe byte changes.
Version 40 – corrections for MSVC++.
Version 36 – support for 1-wire commands.
Version 34 – support for the stepper command.
Version 30 – support for the U421.
Version 28 – initial public release.