Threads#

Introduction#

Threads allow a robot to run multiple tasks simultaneously within the same program. They enable multitasking, letting the robot perform independent actions at the same time.

Note: You must first define a function to use it with a thread.

Constructor – Create and start new threads.

  • Thread – Starts a new thread that runs the specified function in parallel with the main program.

Action – Control running threads.

  • stop – Stops a thread manually, useful for halting background behavior.

Constructor#

Thread#

Thread creates and starts a thread. When you create a thread, you can name it to manage it individually in your project.

Usage:

my_thread = Thread(my_function)

Parameters

Description

my_thread

Optional. A name for the new thread.

my_function

The name of a previously defined function.

Note: A function must always be defined before it is called.

def move_square():
    # Move in a square path
    while True:
        arm.move_inc(100, 0, 0)
        arm.move_inc(0, 100, 0)
        arm.move_inc(-100, 0, 0)
        arm.move_inc(0, 100, 0)

move_square_thread = Thread(move_square)
signal_tower.set_color(SignalTower.BLUE, signal_tower.BLINK)

# Run multiple threads simultaneously
def move_square():
    # Move in a square path
    while True:
        arm.move_inc(100, 0, 0)
        arm.move_inc(0, 100, 0)
        arm.move_inc(-100, 0, 0)
        arm.move_inc(0, 100, 0)

def lights():
    while True:
        # Turn on all LEDs
        signal_tower.set_colors(SignalTower.ON, SignalTower.ON, SignalTower.ON, SignalTower.ON, SignalTower.ON)
        wait(0.25, SECONDS)
        # Turn on just the red LED
        signal_tower.set_colors(SignalTower.ON, SignalTower.OFF, SignalTower.OFF, SignalTower.OFF, SignalTower.OFF)
        wait(0.25, SECONDS)

move_square_thread = Thread(move_square)
lights_thread = Thread(lights)

Action#

stop#

stop stops a thread manually, which is useful when a task is no longer needed or when a program needs to reset or reassign threads. Once a thread is stopped, it cannot be restarted. To run it again, you must create a new thread using Thread.

Usage:

my_thread.stop()

Parameters

Description

my_thread

A previously started thread object. This is the name assigned when the thread was created using Thread.

"""
Run multiple threads simultaneously
Move the end effector, flash lights and display the x position at once
Stop blinking after 2 seconds
"""
def lights():
    while True:
        # Turn on all LEDs
        signal_tower.set_colors(SignalTower.ON, SignalTower.ON, SignalTower.ON, SignalTower.ON, SignalTower.ON)
        wait(0.25, SECONDS)
        # Turn on just the red LED
        signal_tower.set_colors(SignalTower.ON, SignalTower.OFF, SignalTower.OFF, SignalTower.OFF, SignalTower.OFF)
        wait(0.25, SECONDS)

def display_x():
    while True:
        brain.clear_row()
        brain.set_cursor(1, 1)
        brain.print("X Position: {}".format(arm.get_x()))
        wait(50, MSEC)

lights_thread = Thread(lights)     
display_x_thread = Thread(display_x)
arm.move_to(200, 140, 210)

wait(2, SECONDS)
lights_thread.stop()