Limit Switch#

Introduction #

The limit class is used to detect when the Limit Switch is pressed and released.

Class Constructor #

limit(
  triport::port &port);

Class Destructor #

Destroys the limit object and releases associated resources.

virtual ~limit();

Parameters #

Parameter	Type	Description
`port`	`triport::port &`	The 3-Wire Port that the Limit Switch is connected to, written as `Brain.ThreeWirePort.X` or `ExpanderName.X`, where `X` is the port letter (for example, `Brain.ThreeWirePort.A` or `Expander1.A`).

Example #

// Create a limit instance in Port A
limit LimitSwitchA = limit(Brain.ThreeWirePort.A);

Member Functions #

The limit class includes the following member functions:

pressing — Returns a Boolean indicating whether the Limit Switch is being pressed.
pressed — Registers a function to be called when the Limit Switch is pressed.
released — Registers a function to be called when the Limit Switch is released.

Before calling any limit member functions, a limit instance must be created, as shown below:

/* This constructor is required when using VS Code.
Limit Switch configuration is generated automatically
in VEXcode using the Device Menu. Replace the values
as needed. */

// Create a limit instance in Port A
limit LimitSwitchA = limit(Brain.ThreeWirePort.A);

pressing #

Returns if the Limit Switch is currently being pressed.

Available Functions

int32_t pressing();

Parameters

This function does not accept any parameters.

Return Values

Returns an int32_t indicating whether the Limit Switch is being pressed.

1 — The Limit Switch is being pressed.
0 — The Limit Switch is not being pressed.

pressed #

Registers a function to be called when the Limit Switch is pressed.

Available Functions

void pressed( 
  void (* callback)(void) );

Parameters

Parameter	Type	Description
`callback`	`void (*)(void)`	A pointer to a function that will be called when the bumper is pressed. The function must take no parameters and return void.

Return Values

This function does not return a value.

Examples

void switchPressed() {
  // The Brain will print that the Limit Switch was pressed
  // on the Brain's screen.
  Brain.Screen.print("switch pressed");
}

// Run switchPressed when the Limit Switch is pressed.
LimitSwitchA.pressed(switchPressed);

released #

Registers a function to be called when the Limit Switch is released.

Available Functions

void released( 
  void (* callback)(void) );

Parameters

Parameter	Type	Description
`callback`	`void (*)(void)`	A pointer to a function that will be called when the bumper is released. The function must take no parameters and return void.

Return Values

This function does not return a value.

Examples

void switchReleased() {
  Brain.Screen.print("switch released");
}

// Run switchReleased when the Limit Switch is released.
LimitSwitchA.released(switchReleased);