Events#

Introduction#

An event is a starting signal for a set of blocks. Events blocks in VEXcode V5 let different sets of blocks begin at different times. For example, one set of blocks can start when the project begins, and another can start when a signal is sent from somewhere else in the project.

  • when started – Runs the attached stack of blocks when the project starts.

  • when autonomous – Runs the attached stack of blocks when the Brain receives an autonomous signal.

  • when driver control – Runs the attached stack of blocks when the Brain receives a driver control signal.

  • when I receive event – Runs the attached stack of blocks when a specific event is broadcast.

  • broadcast event – Triggers an event without pausing other blocks.

  • broadcast event and wait – Triggers an event and pauses other blocks until the event’s tasks complete.

when started#

The when started hat block starts running the blocks below it when the project begins. Every project needs at least one when started block — without it, the blocks below it will not run. Multiple when started blocks can be used to run different sets of blocks at the same time.

The When started hat block.#
    when started

Parameters

Description

This block has no parameters.

Example

  when started
  [Turn around at the start of the project.]
  turn to heading [180] degrees ▶

when autonomous#

The when autonomous hat block runs the attached stack of blocks when the Brain receives an autonomous signal.

This block is only used for Competition projects.

The When started hat block.#
    when autonomous :: hat events

Parameters

Description

This block has no parameters.

when driver control#

The when driver control hat block runs the attached stack of blocks when the Brain receives a driver control signal.

This block is only used for Competition projects.

The When started hat block.#
    when drive control :: hat events

Parameters

Description

This block has no parameters.

when I receive event#

The when I receive event hat block starts running the blocks below it when a signal with the same event name is broadcast.

The When I receive event hat block.#
    when I receive [my_event v]

Parameters

Description

event

The event to be triggered. Users can select an existing event, create a new one, rename the selected event, or delete it.

Example

  when started
  [Display a message and turn at the same time when the screen is pressed.]
  wait until <screen pressed?>
  broadcast [turn v]
  when I receive [turn v]
  print [Received!] on screen ▶
  turn [right v] for [90] degrees ▶

broadcast event#

The broadcast event stack block sends a signal that starts any when I receive event block with the same event name. The rest of the blocks in the project keep running without waiting for those blocks to finish.

The Broadcast event stack block.#
    broadcast [message1 v]

Parameters

Description

event

The event to trigger. Users can select an existing event, create a new one, rename the selected event, or delete it.

Example

  when started
  [Turn left when the screen is pressed.]
  forever
  if <screen pressed?> then
  broadcast [screen_press v]
  else
  turn [right v]
  when I receive [screen_press v]
  turn [left v]

broadcast event and wait#

The broadcast event and wait stack block sends a signal that starts any when I receive event block with the same event name. The rest of the project will wait for the broadcasted event to finish running.

The Broadcast event and wait stack block.#
    broadcast [message1 v] and wait

Parameters

Description

event

The event to trigger. Users can select an existing event, create a new one, rename the selected event, or delete it.

Example

  when started
  [Move after the Brain's screen is pressed.]
  wait until <screen pressed?>
  broadcast [forward_and_turn v] and wait
  print [Movement done.] on screen ▶
  when I receive [forward_and_turn v]
  drive [forward v] for [100] [mm v] ▶
  turn [right v] for [90] degrees ▶