Brain

Introduction

The VEX EXP Brain Sensing category offers methods for interacting with the Brain’s buttons and connected battery.

This page uses brain as the example Brain name. Replace it with your own configured name as needed.

Below is a list of all methods:

Getters — Return data from the battery and buttons.

• pressing — Returns whether the specified button is being pressed.

• voltage — Returns the battery voltage.

• current — Returns the battery current draw.

• capacity — Returns the remaining battery capacity.

Callbacks - Register functions to be called when the buttons are pressed or released.

• pressed — Registers a function to be called when the specified button is pressed.

• released — Registers a function to be called when the specified button is released.

Getters

pressing

pressing returns a Boolean indicating whether a specific button on the Brain is currently being pressed. This method must be called on a specific button object, such as buttonCheck (see full list of button objects below).

• True — The specified button is being pressed.

• False — The specified button is not being pressed.

Usage:
One of three available button objects can be used with this method, as shown below:

Button	Command
buttonCheck	brain.buttonCheck.pressing() — The Check button
buttonLeft	brain.buttonLeft.pressing() — The Left button
buttonRight	brain.buttonRight.pressing() — The Right button

Parameters	Description
	This method has no parameters.

# Turn when the check button is pressed
while True:
    if brain.buttonCheck.pressing():
        drivetrain.turn(RIGHT)
    else:
        drivetrain.stop()

voltage

Voltage is the electrical pressure supplied to the battery. voltage returns the voltage of the battery as a decimal (float), which can help you check whether the battery is charged enough for the robot to run reliably, ranging from 7.0 to 8.0 Volts.

Usage:
brain.battery.voltage(units)

Parameters	Description
units	Optional. The unit that represents the voltage: MV (default) — Millivolts, or VOLT

# Display the current voltage of the battery
brain.screen.print(brain.battery.voltage())

current

Current is how much electrical flow the robot is using from the battery. current returns the current drawn from the battery in amps as a decimal (float), which can help you see how hard the robot is working or whether motors may be under extra load, ranging from 0.0 to 15.0 Amps.

Usage:
brain.battery.current()

Parameters	Description
	This method has no parameters.

# Display the current of the battery
brain.screen.print(brain.battery.current())

capacity

capacity returns the remaining battery level, as a percentage from 0% to 100%.

Usage:
brain.battery.capacity()

Parameters	Description
	This method has no parameters.

# Display the current battery capacity
brain.screen.print(brain.battery.capacity())

Callbacks

pressed

pressed registers a function to be called when a specific button on the Brain is pressed. This method must be called on a specific button object, such as buttonCheck — (see full list of button objects below).

Usage:
One of three available button objects can be used with this method, as shown below:

Button	Command
buttonCheck	brain.buttonCheck.pressed(callback, arg) — The Check button
buttonLeft	brain.buttonLeft.pressed(callback, arg) — The Left button
buttonRight	brain.buttonRight.pressed(callback, arg) — The Right button

Parameters	Description
callback	A function that is previously defined to execute when the specified button is being pressed.
arg	Optional. A tuple containing arguments to pass to the callback function. See Functions with Parameters for more information.

# Turn in a circle when the left button
# is pressed
def button_pressed():
    drivetrain.turn_for(RIGHT, 360, DEGREES)

brain.buttonLeft.pressed(button_pressed)

released

released registers a function to be called when a specific button on the Brain is released. This method must be called on a specific button object, such as buttonCheck — (see full list of button objects below).

Usage:
One of three available button objects can be used with this method, as shown below:

Button	Command
buttonCheck	brain.buttonCheck.released(callback, arg) — The Check button
buttonLeft	brain.buttonLeft.released(callback, arg) — The Left button
buttonRight	brain.buttonRight.released(callback, arg) — The Right button

Parameters	Description
callback	A function that is previously defined to execute when the specified button is released.
arg	Optional. A tuple containing arguments to pass to the callback function. See Functions with Parameters for more information.

# Turn in a circle when the left button
# is released
def button_released():
    drivetrain.turn_for(LEFT, 360, DEGREES)

brain.buttonLeft.released(button_released)