Timer#

Introduction #

The timer class is used to keep time and interact with a timer independent of the Brain’s timer.

Class Constructor #

timer();

Class Destructor #

Destroys the timer object and releases associated resources.

~timer();

Parameters #

This constructor does not accept any parameters.

Examples #

// Create a timer instance
timer myTimer = timer();

Member Functions #

The timer class includes the following member functions:

reset — Resets the timer to zero.
value — Returns the elapsed time since the timer started.
event — Calls a function after a specified number of milliseconds, with optional arguments.

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

/* This constructor is required to use a 
custom timer. Replace the values
as needed. */

// Create a timer instance
timer myTimer = timer();

/* This constructor is required when using VS Code.
A Brain is generated automatically at the start of
VEXcode projects. */

// Create the Brain to use Brain.Timer
brain Brain = brain();

reset #

Sets the timer to zero.

Available Functions

void reset();

Parameters

This function does not accept any parameters.

Return Values

This function does not return a value.

Examples

while (true) {
  // Clear the timer every time the screen is pressed
  if (Brain.Screen.pressing()) {
    myTimer.reset();
  }
  Brain.Screen.clearScreen();
  Brain.Screen.setCursor(1, 1);
  Brain.Screen.print("Time: %.2f", myTimer.value());
  wait(50, msec);
}

value #

Returns the current value of the timer.

Available Functions

double value();

Parameters

This function does not accept any parameters.

Return Values

A double representing the amount of time passed in seconds.

Notes

The timer begins counting when the timer is constructed.
Calling reset resets the timer value to zero.

Examples

// Display the timer as it ticks up
while (true) {
  Brain.Screen.clearScreen();
  Brain.Screen.setCursor(1, 1);
  Brain.Screen.print("Time: %.2f", myTimer.value());

  wait(50, msec);
}

event #

Registers a callback function to be executed after a specified delay.

Available Functions

1 — Registers a callback to run after a specified delay and passes a user-defined value to the callback.
static void event(
    void (*callback)(void *),
    uint32_t value );

2 — Registers a callback to run after a specified delay.
static void event(
    void (*callback)(void),
    uint32_t value );

Parameters

Parameter	Type	Description
`callback`	`void ()(void )`	A function that will be called after the specified delay and receives a user-defined argument.
`callback`	`void (*)(void)`	A function that will be called after the specified delay.
`value`	`uint32_t`	The delay, in milliseconds, before the callback function is executed.

Return Values

This function does not return a value.

Notes

This function schedules a one-time callback; it does not repeat automatically.
The callback function must return void.
Multiple events may be scheduled at the same time.

Examples

Define the function (outside of int main())

// Create a function to turn the screen orange
void turnOrange() {
  Brain.Screen.clearScreen(orange);
}

int main() {
  /* vexcodeInit() is only required when using VEXcode.
  Remove vexcodeInit() if compiling in VS Code. */
  vexcodeInit();

  timer myTimer = timer();
  // Call turnOrange after 2 seconds
  myTimer.event(turnOrange, 2000);
}