Controls#
Introduction#
The Control blocks in VEXcode AIR manage the flow of a project by handling loops, conditions, delays, and stopping execution. Below is a list of available blocks:
wait — Pauses execution for a specific duration.
wait until — Pauses execution until a specified condition is met.
repeat — Repeats enclosed blocks a specific number of times.
forever — Repeats enclosed blocks indefinitely.
repeat until — Repeats enclosed blocks until a condition is met.
while — Repeats enclosed blocks while a condition remains true.
if — Runs enclosed blocks if a condition is true.
if / else — Runs one set of blocks if a condition is true, otherwise runs another.
if / else if / else — Runs different sets of blocks depending on multiple conditions.
break — Exits a loop immediately.
stop project — Ends the execution of the project.
wait#
The wait block pauses for a specific amount of time before moving to the next block.
wait (1) seconds
Parameters |
Description |
|---|---|
time |
The amount of time to wait, as a positive integer or decimal in seconds. |
Example
when started :: hat events
[Fly for 1 second.]
take off to (500) [mm v] ▶
wait [1] seconds
land ▶
wait until#
The wait until block pauses execution until a specified condition is met before proceeding to the next block.
wait until <>
Parameters |
Description |
|---|---|
condition |
The condition that must be met before moving on to the next block. If it evaluates as:
|
Example
when started :: hat events
[Hover at 200 mm.]
take off to [500] [mm v] ▶
climb [down v]
wait until <(distance [downward v] range in [mm v]) [math_less_than v] [200]>
hover
wait (3) seconds
land ▶
repeat#
The repeat block runs the blocks inside it a set number of times.
repeat [10]
end
Parameters |
Description |
|---|---|
times |
A whole number that sets how many times the repeat block runs. |
Example
when started :: hat events
[Move back and forth four times then land.]
take off to [500] [mm v] ▶
repeat (4)
move [forward v] for (500) [mm v] ▶
wait (1) seconds
move [backward v] for (500) [mm v] ▶
wait (1) seconds
end
land ▶
forever#
The forever block keeps running the blocks inside it again and again without stopping.
forever
end
Parameters |
Description |
|---|---|
This block has no parameters. |
Example
when started :: hat events
[Move with controller.]
take off to [500] [mm v] ▶
forever
move with controller
end
repeat until#
The repeat until block executes the enclosed blocks repeatedly while the condition evaluates as False.
repeat until <>
end
Parameters |
Description |
|---|---|
condition |
An expression or variable that is evaluated before each iteration. If it evaluates as:
|
Example
when started :: hat events
[Move with controller until button 7 is pressed.]
take off to [500] [mm v] ▶
repeat until <controller button [7 v] pressed?>
move with controller
end
land ▶
while#
The while block executes the enclosed blocks repeatedly while the condition evaluates as True.
while <>
end
Parameters |
Description |
|---|---|
condition |
An expression or variable that is evaluated before each iteration. If it evaluates as:
|
Example
when started :: hat events
[Hover at 200 mm.]
take off to [500] [mm v] ▶
while <(distance [downward v] range in [mm v]) [math_greater_than v] [200]>
climb [down v]
end
hover
wait (3) seconds
land ▶
if#
The if block executes the enclosed block of code if the condition evaluates as True.
if <> then
end
Parameters |
Description |
|---|---|
condition |
An expression or variable that is evaluated when the statement runs. If it evaluates as:
|
Example
when started :: hat events
[Take a picture when button 5 is pressed.]
take off to [500] [mm v] ▶
forever
move with controller
if <controller button [5 v] pressed?> then
capture image on [forward v] camera
end
end
if / else#
The if / else block determines which enclosed block of code runs based on whether the condition evaluates as True or False.
if <> then
else
end
Parameters |
Description |
|---|---|
condition |
An expression or variable that is evaluated when the statement runs. If it evaluates as:
|
Example
when started :: hat events
[Climb when the left joystick is moved up.]
take off to [500] [mm v] ▶
forever
if <(controller axis [1 v] position) [> v] [0]> then
climb [up v]
else
hover
end
if / else if / else#
The if / else if / else block structure selects which enclosed block of code runs based on conditions:
if runs its block of code if the condition evaluates as True.
else if checks additional conditions only if all previous conditions evaluated as False. Multiple else if statements can be used.
else runs its block of code only if none of the previous conditions evaluated as True.
if <> then
else if <> then
else
end
Parameters |
Description |
|---|---|
condition |
An expression or variable that is evaluated when the statement runs. The first condition that evaluates as:
|
Example
when started :: hat events
[Move the drone up or down based on the position of the joystick.]
take off to [500] [mm v] ▶
forever
if <(controller axis [1 v] position) [math_greater_than v] [0]> then
move [forward v]
else if <(controller axis [1 v] position) [math_less_than v] [0]> then
move [reverse v]
else
hover
end
end
break#
The break block exits a loop immediately.
Loops include:
break
Parameters |
Description |
|---|---|
This block has no parameters. |
Example
when started :: hat events
[Land when button 5 is pressed.]
take off to [500] [mm v] ▶
forever
move with controller
if <controller button [5 v] pressed?> then
break
end
end
land ▶
stop project#
The stop project block ends a running project.
stop project :: control cap
Parameters |
Description |
|---|---|
This block has no parameters. |
Example
when started :: hat events
[Stop motors after landing.]
take off to [500] [mm v] ▶
wait [1] seconds
land ▶
stop project