oHeading Object

Description
Operation
Properties

Examples
Related
Version History & Bug list

The oHeading Object manages a signed 8-Bit variable intended to be used as a URCP Heading value so that it can be used in a virtual circuit. As well as the value of the variable, status properties are provided that can also be used in a virtual circuit.

The oHeading Object has properties and methods that support the URCP Heading value .

URCP Heading values deal with circles, trigonometry, angles and headings. The common numbering system chosen for this is Binary-Radians (Brads) which divides a full circle (360 degrees) into 256 even parts. 256 brads per 360 degrees is used so that a single byte can represent a full circle.

Objects such as the oJoystick, oTracker, oServoX, etc. use URCP Heading values. This allows one device such as the oTracker to read a heading from a line on the ground. This value then can be copied to an oServoX Object to steer a robot in the direction needed to follow a line. Similarly, the oJoystick can be used to provide the heading.

There are three main differences between this object and a standard Char variable.

This Object's Value property is an instance of the oValue Object which can be pointed to by a Virtual Circuit.
This Object maintains status bits which can be pointed to by Virtual Circuits.
This Object is 1 byte larger in order to store the status information.

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

	Object	Size	Description	A1	A2	B1	B2	C1
	oHeading	2 Bytes	An Object that manages a URCP heading value.			x	x	x

Operation:

An oHeading Object variable stores a signed 8 or 16 Bit value in its Value property and maintains other values that represent the status of those 8 bits.

The Negative property indicates the Most-Significant-Bit of the value which is used to indicate when the value is a negative number.

The NonZero Property indicates if the value is not zero.

Properties:

The following table lists the properties of the oHeading Object:

Property
Description

Value

The heading value.

Object Class: oValue Value Range: 0 - 255

Data Type: Numeric Default Value: 0

Value Pressed

URCP Heading

-128 "South"

-64 "West"

0 "North"

64 "East"

Negative

A value that indicates the Value property is less than zero.

Object Class: oLogic Value Range: 0 - 1

Data Type: Numeric Default Value: 0

Notes on virtual circuit usage: Not all implementations of the oHeading Object have a linkable Negative property. While all instance of the oHeading Object that you create in your programs will have a linkable Negative property, some of the ooPIC Objects create a custom oHeading Object instance that cannot.

Negative Description

0
The Value property is a Positive value.

1
The Value property is Negative Value.

NonZero

A value that indicates the Value property is more than or less than zero.

Object Class: oLogic Value Range: 0 - 1

Data Type: Numeric Default Value: 0

Notes on virtual circuit usage: Not all implementations of the oHeading Object have a linkable NonZero property. While all instance of the oHeading Object that you create in your programs will have a linkable NonZero property, some of the ooPIC Objects create a custom oHeading Object instance that cannot.

NonZero Constant Description

0 cvFalse
The Value property is zero.

1 cvTrue
The Value property is not zero.

Data

The data for the Value property.

Object Class: oVar8 Value Range: 0 - 256

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