oButton Object

Description
Operation
Properties

Examples
Connections
Related
Version History & Bug list

A Hardware Object that reads the state of a switch and controls the state of an LED using a single I/O line. The switch can be configured as a push button or a toggle button and the LED can be set to steady on, steady off or 3 different patterns of blinking.

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

	Object	Size	Description	A1	A2	B1	B2	C1
	oButton	3 Bytes	Reads the position of a switch and controls an LED light.				x	x

Operation:

An oButton Object continuously cycles between controlling one of two different objects each of which share a single I/O line. The first functions as a digital Input which reads a push-button style switch and the second functions as a digital output which controls an LED. In order for both the LED and the push button to be connected to the same I/O line, they Must be connected to the I/O line through a resister as indicated by the wiring diagram in the Connection section.

In the first half of the cycle, when operating as a digital Input, the oDIO1RW Object (DIO property) is used to read the position of a switch. The Position property is set depending on the combination of the state of the switch and the Mode property.

If the Mode property is set to 0, then the push button is treated as a regular push button where pressed is on, and released is off. If the Mode property is 1, then the push button is treated as a toggle switch where pressed once is on and pressed a second time is off.

In both modes, changing from off to on or on to off sets the Position property accordingly. Note that the Position property is only modified when the push button physically changed state. This allows the application program to preset the Position property or to change it after it has been set by the user's interaction.

In the second half of the cycle, when the oButton is operating as a digital Output, the oLEDB Object (LED property) is used to control an LED. the Position property is used to specify whether or not the LED is on or off. If 1, then the LED is turned on and if 0, then the LED is turned off. Some of the properties of the oLED Object can be changed without interfering with the oButton's control. For instance, the LED.Blink property changes the appearance of the LED when it is on. If LED.Blink is set to 0, then the LED glows continuously. However, LED.Blink is 1 or more, then the LED blinks in various ways. (See the oLEDB Object for more detail)

In normal operation, the Position property controls the state of the LED. By setting the Option property to 1, this control can be turned off. Note that when the Position property is in control, the oLEDB Object's Operate property is over-ridden by the oButton's Position property and therefore has no effect. However, by setting the Option property to 1, the oLEDB Object's Operate property regains control.

Properties:

The following table lists the properties of the oButton Object:

Property
Description

Position

A value that indicates the position of the button.

Object Class: oLogic Value Range: 0 - 1

Data Type: Numeric Default Value: 0

Position Constant Description

0 cvOff The button state is off.

1 cvOn The button state is on.

IsOn

A value that indicates if the button is in the ON position.

Object Class: oProperty Value Range: 0 - 1

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

IsOff

A value that indicates if the button is in the OFF position.

Object Class: oProperty Value Range: 0 - 1

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

IOLine

A value that specifies which I/O Line is connected to the switch and the LED.

Object Class: oIOLine Value Range: 0 - 31

Data Type: Numeric Default Value: 0

Some I/O Lines have special purposes. Be sure to see oIOLine help file for details.

Mode

A value that selects if the button is treated as a push-button or a toggle-switch.

Object Class: oSelect0to1 Value Range: 0 - 1

Data Type: Numeric Default Value: 0

Mode Description

0 The button is treated as a push button. Pressed is on, Released is off.

1 The button is treated as a toggle switch, Pressed once is on, Pressed second time is off.

Option

A value that selects if the LED is set on or off based on the Position property.

Object Class: oSelect0to1 Value Range: 0 - 1

Data Type: Numeric Default Value: 0

Option Description

0 The LED is controlled by the Position property.

1 The LED is controlled by the LED.Operate property.

DIO

The I/O function object used to read the Button.

Object Class: oDIO1RW Value Range: 0 - 1

Data Type: Numeric Default Value: 0

LED

The LED object used to control the LED.

Object Class: oLEDB Value Range: 0 - 1

Data Type: Numeric 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 example, the oButton Object is used to read a switch and control and LED on I/O line 7. When the button position is 1, a speaker will produce a tone. The button is set to toggle mode, so one press turns the LED and the speaker on and a second press turns the speaker off.

Dim A As New oButton
Dim B As New oSpeaker

Sub Main()
  A.IOLine = 7
  A.Mode = 1
  B.Tone = 40000
  Do
    B.Operate = A.Position
  Loop
End Sub

Connections:

The actual values of the two resistors are based on the power requirements of the LED that is used in the circuit. Note that both resistors need to be the same value.