Robot-Specific Python

Introduction

The V5RC 25-26 Push Back Playground features methods exclusive to the build designed for this Playground, including two motor options, AI Vision Sensor, Optical Sensor, and Game Positioning System (GPS) Sensor.

All standard VEXcode VR methods are available for use in the V5RC 25-26 Push Back Playground.

Below is a list of all available Playground-specific methods:

Motion – Move and track the robot’s motors.

• Actions

  • spin – Spins the selected motor or motor group indefinitely.

  • spin_for – Spins a motor or group for a specific distance in degrees or turns.

  • spin_to_position – Spins a motor or motor group to a set position.

  • stop – Stops a specific motor or motor group from spinning.

• Mutators

  • set_position – Sets the encoder value of a motor or motor group.

  • set_velocity – Sets the speed of a motor or motor group as a percentage.

  • set_timeout – Limits how long a motor block waits before giving up if movement is blocked.

• Getters

  • is_done – Returns a Boolean indicating whether the motor is no longer spinning.

  • is_spinning – Returns a Boolean indicating whether the motor is currently spinning.

  • position – Returns the motor’s current rotational position in degrees or turns.

  • velocity – Returns the motor’s current velocity in % or rpm.

AI Vision - Capture and analyze objects using the AI Vision Sensor.

• Getters

  • take_snapshot – Returns a tuple of detected objects based on a given signature.

• Properties

  • width – Width of the detected object in pixels.

  • height – Height of the detected object in pixels.

  • centerX – X position of the object’s center in pixels.

  • centerY – Y position of the object’s center in pixels.

  • originX – X position of the object’s top-left corner in pixels.

  • originY – Y position of the object’s top-left corner in pixels.

  • id – Classification or tag ID of the object.

Sensing - Utilize the robot’s various sensors.

• Optical

  • is_near_object – Returns whether a detected object is near the Optical Sensor.

  • color – Returns the color detected from the Optical Sensor.

  • brightness – Returns the brightness percentage detected by the sensor.

  • hue – Returns the hue value of the detected color.

  • object_detected – Registers a callback function for when the Optical Sensor detects an object.

  • object_lost – Registers a callback function for when the Optical Sensor loses an object.

• GPS

  • x_position – Returns the current x coordinate of a GPS Sensor on the field.

  • y_position – Returns the current y coordinate of a GPS Sensor on the field.

  • heading – Returns the heading that the robot is currently facing based on the GPS Sensor’s readings from 0 to 359 degrees.

The examples on this page use the default Playground start position.

Motion

Actions

spin

spin spins a motor or motor group in the specified direction indefinitely.

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

motor	Command
intake_motor	intake_motor.spin(direction) — Intake Motors
conveyor_motor	conveyor_motor.spin(direction) — Conveyor Motors

Parameters	Description
direction	The direction for the motor to spin: FORWARD — Spins the Conveyor up or the Intake in the intake direction. REVERSE — Spins the Conveyor down or the Intake in the outtake direction.

def main():
    # Pick up a second Block
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 350, MM)

# VR threads — Do not delete
vr_thread(main)

spin_for

spin_for spins a motor or motor group for a given amount of degrees or turns.

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

motor	Command
intake_motor	intake_motor.spin_for(direction, distance, units, wait) — Intake Motors
conveyor_motor	conveyor_motor.spin_for(direction, distance, units, wait) — Conveyor Motors

Parameters	Description
direction	The direction for the motor to spin: FORWARD – Spins the Conveyor up or the Intake in the intake direction. REVERSE – Spins the Conveyor down or the Intake in the outtake direction.
distance	The distance for the motor to spin as an integer.
units	The unit that represents the distance to rotate: DEGREES TURNS
wait	Optional. wait=True (default) — The robot waits until spin_for is complete before executing the next line of code. wait=False — The robot starts the action and moves on to the next line of code right away, without waiting for spin_for to finish.

def main():
    # Pick up a second Block
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 350, MM)

# VR threads — Do not delete
vr_thread(main)

spin_to_position

spin_to spins a motor or motor group to a given position.

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

motor	Command
intake_motor	intake_motor.spin_to_position(angle, units, wait=True) — Intake Motors
conveyor_motor	conveyor_motor.spin_to_position(angle, units, wait=True) — Conveyor Motors

Parameters	Description
angle	The specific angle or number of turns that the motor will spin to.
units	The unit that represents the angle to rotate to: DEGREES TURNS
wait	Optional. wait=True (default) — The robot waits until spin_to_position is complete before executing the next line of code. wait=False — The robot starts the action and moves on to the next line of code right away, without waiting for spin_to_position to finish.

def main():
    # Pick up a second Block
    conveyor_motor.spin_to_position(150, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 350, MM)

# VR threads — Do not delete
vr_thread(main)

stop

stop stops a motor or motor group from spinning.

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

motor	Command
intake_motor	intake_motor.stop() — Intake Motors
conveyor_motor	conveyor_motor.stop() — Conveyor Motors

Parameters	Description
	This method has no parameters.

def main():
    # Pick up a second Block
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 350, MM)
    intake_motor.stop()

# VR threads — Do not delete
vr_thread(main)

Mutators

set_position

set_position sets a motor’s or motor group’s encoder position to the given position value.

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

motor	Command
intake_motor	intake_motor.set_position(position, units) — Intake Motors
conveyor_motor	conveyor_motor.set_position(position, units) — Conveyor Motors

Parameters	Description
position	The specific integer for the motor’s encoder to be set to.
units	The unit that represents the angle to rotate to: DEGREES TURNS

def main():
    # Pick up a second Block
    conveyor_motor.set_position(-150, DEGREES)
    conveyor_motor.spin_to_position(0, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 350, MM)

# VR threads — Do not delete
vr_thread(main)

set_velocity

set_velocity sets the speed of a motor or motor group.

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

motor	Command
intake_motor	intake_motor.set_velocity(velocity, units) — Intake Motors
conveyor_motor	conveyor_motor.set_velocity(velocity, units) — Conveyor Motors

Parameters	Description
velocity	The speed that the V5 Motor will spin at, ranging from 0 to 100.
units	The unit that represents the new velocity: PERCENT

def main():
    # Pick up a second Block
    conveyor_motor.set_velocity(90, PERCENT)
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 400, MM)

# VR threads — Do not delete
vr_thread(main)

set_timeout

set_timeout sets a time limit for a motor’s or motor group’s movement commands. This prevents Motion commands that do not reach their intended position from preventing subsequent commands from running.

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

motor	Command
intake_motor	intake_motor.set_timeout(value, units) — Intake Motors
conveyor_motor	conveyor_motor.set_timeout(value, units) — Conveyor Motors

Parameters	Description
value	The amount of time the motor will wait before stopping.
units	The unit to represent the timeout: SECONDS MSEC — milliseconds

def main():
    # Pick up a second Block
    conveyor_motor.set_timeout(0.5, SECONDS)
    conveyor_motor.spin_to_position(1000, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 400, MM)

# VR threads — Do not delete
vr_thread(main)

Getters

is_done

is_done returns a Boolean indicating whether the specified motor or motor group is not spinning.

• True – The specified motor is not spinning.

• False – The specified motor is spinning.

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

motor	Command
intake_motor	intake_motor.is_done() — Intake Motors
conveyor_motor	conveyor_motor.is_done() — Conveyor Motors

Parameters	Description
	This method has no parameters.

def main():
    # Pick up a second Block
    conveyor_motor.spin_to_position(300, DEGREES, wait=False)
    wait(0.1, SECONDS)
    while not conveyor_motor.is_done():
        drivetrain.drive(FORWARD)
        intake_motor.spin(FORWARD)
        wait(5, MSEC)
    drivetrain.stop()
    intake_motor.stop()

# VR threads — Do not delete
vr_thread(main)

is_spinning

is_spinning returns a Boolean indicating whether the specified motor or motor group is spinning.

• True – The specified motor is spinning.

• False – The specified motor is not spinning.

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

motor	Command
intake_motor	intake_motor.is_spinning() — Intake Motors
conveyor_motor	conveyor_motor.is_spinning() — Conveyor Motors

Parameters	Description
	This method has no parameters.

def main():
    # Pick up a second Block
    conveyor_motor.spin_to_position(300, DEGREES, wait=False)
    wait(0.1, SECONDS)
    while conveyor_motor.is_spinning():
        drivetrain.drive_for(FORWARD, 200, MM)
        intake_motor.spin(FORWARD)

# VR threads — Do not delete
vr_thread(main)

position

position returns the total distance the specified motor or motor group has rotated.

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

motor	Command
intake_motor	intake_motor.position(units) — Intake Motors
conveyor_motor	conveyor_motor.position(units) — Conveyor Motors

Parameters	Description
units	The units that represent the motor’s position: DEGREES TURNS

def main():
    # Pick up a second Block
    while conveyor_motor.position(DEGREES) < 150:
        conveyor_motor.spin(FORWARD)
        wait(2, MSEC)
    conveyor_motor.stop()
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 400, MM)

# VR threads — Do not delete
vr_thread(main)

velocity

velocity returns the current rotational speed of the motor or motor group.

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

motor	Command
intake_motor	intake_motor.velocity(units) — Intake Motors
conveyor_motor	conveyor_motor.velocity(units) — Conveyor Motors

Parameters	Description
units	The unit that represent the motor’s position: PERCENT

def main():
    # Pick up a second block
    conveyor_motor.set_velocity(100, PERCENT)
    conveyor_motor.spin_to_position(300, DEGREES, wait=False)
    wait(0.2, SECONDS)
    brain.screen.print(conveyor_motor.velocity(PERCENT))
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 400, MM)

# VR threads — Do not delete
vr_thread(main)

AI Vision

Getters

take_snapshot

take_snapshot filters the data from the AI Vision Sensor frame to return a tuple.

The tuple stores objects ordered from largest to smallest by width, starting at index 0. Each object’s properties can be accessed using its index. An empty tuple is returned if no matching objects are detected.

Usage:
ai_vision.take_snapshot(signature)

Parameters	Description
signature	Which signature to get data of. The only available signature is: AiVision.ALL_AIOBJS - Detects Red and Blue Blocks.

def main():
    # If an object is detected, pick it up
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    while True:
        ai_objects = ai_vision.take_snapshot(AiVision.ALL_AIOBJS)
        if ai_objects:
            intake_motor.spin(FORWARD)
            drivetrain.drive(FORWARD)
            while not bumper.pressing():
                wait(2, MSEC)
            drivetrain.stop()
            break

# VR threads — Do not delete
vr_thread(main)

Properties

There are seven properties that are included with each object stored in a tuple after take_snapshot is used.

Some property values are based off of the detected object’s position in the AI Vision Sensor’s view at the time that take_snapshot was used. The AI Vision Sensor has a resolution of 320 by 240 pixels.

.width

.width returns the width of the detected object in pixels, which is an integer between 1 and 320.

def main():
    # If an object is detected, approach and pick it up
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    while True:
        ai_objects = ai_vision.take_snapshot(AiVision.ALL_AIOBJS)
        if ai_objects:
            if ai_objects[0].width > 65:
                drivetrain.stop()
                break
            else:
                intake_motor.spin(FORWARD)
                drivetrain.drive(FORWARD)

# VR threads — Do not delete
vr_thread(main)

.height

.height returns the height of the detected object in pixels, which is an integer between 1 and 240.

def main():
    # If an object is detected, approach and pick it up
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    while True:
        ai_objects = ai_vision.take_snapshot(AiVision.ALL_AIOBJS)
        if ai_objects:
            if ai_objects[0].height > 55:
                drivetrain.stop()
                break
            else:
                intake_motor.spin(FORWARD)
                drivetrain.drive(FORWARD)

# VR threads — Do not delete
vr_thread(main)

.centerX

.centerX returns the x-coordinate of the detected object’s center in pixels, which is an integer between 0 and 320.

def main():
    # Pick up a Block from the top left group
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    drivetrain.turn_for(LEFT, 80, DEGREES)
    drivetrain.drive_for(FORWARD, 200, MM)
    drivetrain.set_turn_velocity(20, PERCENT)
    drivetrain.turn(LEFT)
    while True:
        ai_objects = ai_vision.take_snapshot(AiVision.ALL_AIOBJS)
        if ai_objects:
            if 140 < ai_objects[0].centerX < 180:
                intake_motor.spin(FORWARD)
                drivetrain.drive(FORWARD)
                while not bumper.pressing():
                    wait(2, MSEC)
                drivetrain.stop()

# VR threads — Do not delete
vr_thread(main)

.centerY

.centerY returns the y-coordinate of the detected object’s center in pixels, which is an integer between 0 and 240.

def main():
    # If an object is detected, approach and pick it up
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    while True:
        ai_objects = ai_vision.take_snapshot(AiVision.ALL_AIOBJS)
        if ai_objects:
            if ai_objects[0].centerY > 140:
                drivetrain.stop()
                break
            else:
                intake_motor.spin(FORWARD)
                drivetrain.drive(FORWARD)

# VR threads — Do not delete
vr_thread(main)

.originX

.originX returns the x-coordinate of the top-left corner of the detected object’s bounding box in pixels, which is an integer between 0 and 320.

def main():
    # Pick up a Block from the top left group
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    drivetrain.turn_for(LEFT, 80, DEGREES)
    drivetrain.drive_for(FORWARD, 300, MM)
    drivetrain.set_turn_velocity(20, PERCENT)
    drivetrain.turn(RIGHT)
    while True:
        ai_objects = ai_vision.take_snapshot(AiVision.ALL_AIOBJS)
        if ai_objects:
            if 100 < ai_objects[0].originX < 140:
                intake_motor.spin(FORWARD)
                drivetrain.drive(FORWARD)
                while not bumper.pressing():
                    wait(2, MSEC)
                drivetrain.stop()

# VR threads — Do not delete
vr_thread(main)

.originY

.originY returns the y-coordinate of the top-left corner of the detected object’s bounding box in pixels, which is an integer between 0 and 240.

def main():
    # If an object is detected, approach and pick it up
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    while True:
        ai_objects = ai_vision.take_snapshot(AiVision.ALL_AIOBJS)
        if ai_objects:
            if ai_objects[0].originY > 120:
                drivetrain.stop()
                break
            else:
                intake_motor.spin(FORWARD)
                drivetrain.drive(FORWARD)

# VR threads — Do not delete
vr_thread(main)

.id

.id returns the ID of the detected AI Classification as an integer.

AI Classification	id	Signature
BlueBlock	1	GameElements.BLUE_BLOCK
RedBlock	2	GameElements.RED_BLOCK

def main():
    # Pick up a Red Block from the top left group
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    drivetrain.turn_for(LEFT, 80, DEGREES)
    drivetrain.drive_for(FORWARD, 300, MM)
    while True:
        ai_objects = ai_vision.take_snapshot(AiVision.ALL_AIOBJS)
        if ai_objects:
            drivetrain.drive(FORWARD)
            if (ai_objects[0].id) == 2:
                intake_motor.spin(FORWARD)
                while not bumper.pressing():
                    wait(2, MSEC)
                drivetrain.stop()
                break

# VR threads — Do not delete
vr_thread(main)

Sensing

Optical

is_near_object

is_near_object returns a Boolean indicating whether or not the Optical Sensor detects an object close to the sensor.

• True – The object is close to the Optical Sensor.

• False – The object is not close to the Optical Sensor.

Usage:
optical.is_near_object()

Parameters	Description
	This method has no parameters.

def main():
    # Move the preloaded Block to the top of the Conveyor
    conveyor_motor.spin(FORWARD)
    while not optical.is_near_object():
        wait(2, MSEC)
    conveyor_motor.stop()

# VR threads — Do not delete
vr_thread(main)

color

color returns the color detected by the Optical Sensor:

Color Returned:
NONE – No color detected. RED GREEN BLUE YELLOW ORANGE PURPLE CYAN

Usage:
optical.color()

Parameters	Description
	This method has no parameters.

def main():
    # Pick up and move a Blue Block to the top of the Conveyor
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 360, MM)
    conveyor_motor.spin(FORWARD)
    while not optical.color() == BLUE:
        wait(2, MSEC)
    conveyor_motor.stop()

# VR threads — Do not delete
vr_thread(main)

brightness

brightness returns the brightness value detected by the Optical Sensor as a percent from 0% to 100%.

Usage:
optical.brightness()

Parameters	Description
	This method has no parameters.

def main():
    # Move the preloaded Block to the top of the Conveyor
    conveyor_motor.spin(FORWARD)
    while not 0 < optical.brightness():
        wait(2, MSEC)
    conveyor_motor.stop()

# VR threads — Do not delete
vr_thread(main)

hue

hue returns the hue detected by the Optical Sensor.

Hue values range from 0 to 359 degrees, corresponding to positions on the color wheel shown below.

Usage:
optical.hue()

Parameters	Description
	This method has no parameters.

def main():
    # Pick up and move a Blue Block to the top of the Conveyor
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive_for(FORWARD, 360, MM)
    conveyor_motor.spin(FORWARD)
    while not 220 < optical.hue() < 260:
        wait(2, MSEC)
    conveyor_motor.stop()

# VR threads — Do not delete
vr_thread(main)

object_detected

object_detected registers a callback function for when the Optical Sensor detects an object.

Usage:
optical.object_detected(callback, arg)

Parameters	Description
callback	A function that will be called when an object is detected.
arg	Optional. A tuple that is used to pass arguments to the callback function.

def ready_block():
  # Stop the conveyor when Block is at the Sensor
  conveyor_motor.stop()

def main():
  # Move the preloaded Block near the top of the Conveyor
  conveyor_motor.spin(FORWARD)
  optical.object_detected(ready_block)

# VR threads — Do not delete
vr_thread(main)

object_lost

object_lost registers a callback function for when the Optical Sensor loses a previously detected object.

Usage:
optical.object_lost(callback, arg)

Parameters	Description
callback	A function that will be called when a detected object is lost.
arg	Optional. A tuple that is used to pass arguments to the callback function.

def ready_block():
  # Stop the conveyor when Block is at the top
  conveyor_motor.stop()

def main():
  # Move the preloaded Block to the top of the Conveyor
  conveyor_motor.spin(FORWARD)
  optical.object_lost(ready_block)

# VR threads — Do not delete
vr_thread(main)

GPS

x_position

x_position returns the current x coordinate of a GPS (Game Positioning System™) Sensor on the field.

Usage:
gps.x_position(units)

Parameters	Description
units	The unit of the offset value: INCHES MM

def main():
    # Pick up a second Block
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive(FORWARD)
    while not gps.x_position(MM) > -795:
        wait(2, MSEC)
    drivetrain.stop()

# VR threads — Do not delete
vr_thread(main)

y_position

y_position returns the current y coordinate of a GPS (Game Positioning System™) Sensor on the field.

Usage:
gps.y_position(units)

Parameters	Description
units	The unit of the offset value: INCHES MM

def main():
    # Pick up a second Block
    conveyor_motor.spin_for(FORWARD, 200, DEGREES)
    intake_motor.spin(FORWARD)
    drivetrain.drive(FORWARD)
    while not -450 > gps.y_position(MM):
        wait(2, MSEC)
    drivetrain.stop()

# VR threads — Do not delete
vr_thread(main)

heading

heading returns the heading that the robot is currently facing based on the GPS (Game Positioning System™) Sensor’s readings from 0 to 359 degrees.

Usage:
gps.heading()

Parameters	Description
	This method has no parameters.

def main():
    # Score the preloaded Block into a Center Goal
    drivetrain.set_turn_velocity(30, PERCENT)
    drivetrain.turn(LEFT)
    while not 40 > gps.heading():
        wait(2, MSEC)
    drivetrain.drive_for(FORWARD, 1000, MM)
    drivetrain.turn(RIGHT)
    while not gps.heading() > 310:
        wait(2, MSEC)
    drivetrain.drive_for(REVERSE, 400, MM)
    conveyor_motor.spin(FORWARD)

# VR threads — Do not delete
vr_thread(main)