DirectionA

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DirectionA

Description:

This is a USBm.dll function that sets the i⁄o direction of port A.

Command Syntax: (USBm.dll)

USBm_DirectionA(device, dir0, dir1)

The USBm_DirectionA function syntax has these parts:

Part	Description
device	A zero-based index to address the appropriate USB device.
dir0	Port direction.
dir1	Port direction.

Remarks:

The individual pins of the ports can be set to input, or output. Input is set when both bits associated with a particular line are set to 0. There are different types of outputs available for the board, but generally setting both of the direction bits to 1 will suffice.

To set all pins in the port to input, set dir0 = 00h and dir1 = 00h. To set the highest port pin to output set the highest bit in both registers, dir0 = 80h and dir1 = 80h.

VB Declaration

Public Declare Function USBm_DirectionA _
    Lib "USBm.dll" _
        (ByVal device As Byte, _
        ByVal dir0 As Byte, _
        ByVal dir1 As Byte) _
    As Integer

VB Example

USBm_DirectionA 1, 0, 0

This code fragment sets port A of device 1 to input.

C Example

-TBD-

Hardware: U401 USB Interface U421 USB Interface

Programming: USBm DLL Programming Download Files

Application Notes: U4x1 Application Notes Misc Applications and Information FAQ