oIOLineA Object

Controls a single I/O line accessible by the PIC's A2D Module.

The following table lists the size and availability of the oIOLineA Object.

	Object	Size	Description	A1	A2	B1	B2	C1
	oIOLineA	1 Byte	Controls a single I/O line accessible by the PIC's A2D Module.	x	x	x	x	x

Operation:

Once the Line property is, which specifies which Analog I/O line to use, the Direction and the State properties reference the actual hardware that controls the Direction and State of the specified PIC I/O Pin.

The State property references the electrical state of the I/O Pin specified.

The Direction property specifies if the I/O Pin is an input or an output. When the Direction property is set to 0 (cvOutput), then the specified Pin will output either 0 or 5 Volts depending on what the State property is set to. When the Direction property is set to 1 (cvInput), then the specified Pin is set to be an input and the State property will report whether or not 5 Volts is being applied to the Pin by an external device.

Note that since the Direction and State properties reference the actual hardware of the specified PIC I/O Pin, then changing the Line property will also re-index the hardware that the Direction and State properties reference. This means that you MUST set the Line property BEFORE you set the Direction property for the Direction property to affect the I/O line you want to use. For example, if Pin 1 is specified and it is an input, then the Direction property would read 1 and the State property would report the current electrical state of Pin 1. Then if the Line property was changed to 2 and Pin 2 was an output, the Direction property will now read 0 and the State property would report the current electrical state of Pin 2. See other examples below.

Note that the oIOLineA Object does not control the analog conversion module. That job is reserved for the oA2D Object which uses the oIOLineA Object to designate which I/O Line it is going to use.

Also note that the Line property is the default property. This means that if an instance of the oIOLineP Object exists, then not only can the Line property be set to 1 by assigning it with the statement "IOLine.Line = 1", it can also be set with the statement: "IOLine = 1" as demonstrated in the oA2D Object.

Properties:

The following table lists the properties of the oIOLineA Object:

Property
Description

Line

A value that selects the I/O Line to use.

Object Class: oSelect0to7 Value Range: 0 - 7

Data Type: Numeric Default Value: 0

Line Version Description

0 A.1.0 - B.1.0
I/O Line 4 is referenced. 4 can be assigned to Line in place of 0 but it will read back as 0.

0 B.2.0
No I/O Line is referenced.

1 - 3 All
The specified IOLine is referenced.

4 - 7 A.1.0 - B.1.0 Values of 4 - 7 will be treated as values 0 - 3.

4 - 7 B.2.0
The specified IOLine is referenced.

Direction

A value that specifies if the I/O line is a Input or an Output.

Object Class: oProperty Value Range: 0-1

Data Type: Numeric Default Value: 1 (cvInput)

Direction Constant Description

0 cvOutput The specified I/O Line is an output and the State property is written to it.

1 cvInput The specified I/O Line is High-Z and the State property is read from it.

State

A value that indicates the current electrical state on the I/O line.

Object Class: oProperty Value Range: 0 - 1

Data Type: Numeric Default Value: 0

Value Constant Description

0 cvOff The specified I/O line is at 0 Volts.

1 cvOn The specified I/O line is at +5 Volts.

IsLow

A value that indicates if the current state is Low.

Object Class: oProperty Value Range: 0 - 1

Data Type: Numeric (Read-Only) Default Value: (Not State)

The IsLow property reports the reverse value of the State property. It is worded to be understood in an evaluation such as: if X.IsLow then...

IsHigh Description

0 The Electrical State is at a Logical High (5 Volts).

1 The Electrical State is at a Logical Low (0 Volts).

IsHigh

A value that indicates if the current state is High.

Object Class: oProperty Value Range: 0 - 1

Data Type: Numeric (Read-Only) Default Value: 0

The IsHigh property reports the same value as the State property. It is worded to be understood in an evaluation such as: if X.IsHigh then...

IsHigh Description

0 The Electrical State is at a Logical Low (0 Volts).

1 The Electrical State is at a Logical High (5 Volts).

Port

The PIC Hardware object used to control the I/O line.

Object Class: oPort Value Range: 0

Data Type: Numeric (Read-Only) Default Value: 0

Address

Returns a pointer to the address of the oCounter Object instance.

Object Class: oAddress Value Range: 0 - 127

Data Type: Pointer (Read Only) Default Value: Address of Object

Examples:

In the following examples, the oIOLineA Object is used.

Visual Basic Syntax

C and Java Syntax

'This program turns an 
'output on and then off at
'a rate of once a second.

Dim A As New oIOLineA

Sub Main()
  A.Line = 1
  A.Direction = cvOutput
  Do
    A.State = Not A.State
    ooPIC.Delay = 1000
  Loop
End Sub

//This program turns an 
//output on and then off at
//a rate of once a second.

oIOLineA A = New oIOLineA;

Void Main(Void){
  A.Line = 1;
  A.Direction = cvOutput;
  Do{
    A.State = Not A.State;
    ooPIC.Delay = 1000;
  }
}

Basic Syntax

'This program turns an 
'output on and then off at
'a rate of once a second.

A As oIOLineA(1,cvOutput)

Do
  A.State = Not A.State
  ooPIC.Delay = 1000
Loop