消息链接#

介绍 #

MessageLink允许两个V5大脑通过发送带有可选少量数据的短字符串消息进行通信。它专为机器人之间的协调而设计，例如启动程序、共享传感器结果或触发另一个机器人的行为。

Every usage of send adds a message to the linked V5 Brain’s queue, and the queue is read first-in, first-out (FIFO). If multiple messages are sent before the other V5 Brain uses receive, they will be stored and returned one at a time in the order they were sent. Because messages can queue, repeatedly sending the same status every loop may create backlog; for time-critical logic, send only when values change.

Important: Both robots must be running projects that use MessageLink at the same time, or no messages will be sent/received.

This page uses link as the example MessageLink name. Replace it with your own configured name as needed.

以下是可用方法列表：

is_linked – Returns whether this Brain is actively connected to its paired Brain.
send – Sends a message to the paired Brain.
receive – Waits for and returns the next incoming message.
received – Registers a function to be called whenever a new message is received.

创建链接 #

在两个 V5 大脑上创建 MessageLink，以在它们之间建立通信通道——可以通过 V5 机器人无线电进行无线通信，也可以通过有线智能电缆进行通信——以便机器人可以互相发送消息。

MessageLink(smartport, name, linktype, wired)

范围	描述
`smartport`	The Smart Port used for this link—the port the V5 Robot Radio is connected to (wireless) or the Smart Cable is plugged into (wired). Written as `Ports.PORTx` where x is the port number.
`name`	此链接的唯一名称（字符串形式）注意：此名称应足够长，以生成唯一的 ID，避免与其他团队的链接意外匹配。
`linktype`	The role this Brain will use for this link pair. Each pair must include one Manager and one Worker: `VexlinkType.MANAGER` – Use for the robot that will send more or larger messages. Managers have higher outbound bandwidth (~1040 bytes/sec). `VexlinkType.WORKER` – Use for the robot that will send fewer or smaller messages. Workers have lower outbound bandwidth (~520 bytes/sec).
`wired`	Optional. Whether this link is wired or wireless: `True` – The V5 Brains are connected via a Smart Cable. `False` (default) – The V5 Brains connect wirelessly using V5 Robot Radios.

机器人 1 的代码

"""
Create a wireless link in Port 1
name: VEXRoboticsLink123456789
linktype: Manager
"""
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.MANAGER)

机器人2的代码

"""
Create a wireless link in Port 1
name: VEXRoboticsLink123456789
linktype: Worker
"""
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.WORKER)

可用方法 #

一旦 MessageLink 设置完毕且 Brains 连接成功，您就可以使用以下方法发送、接收和回复消息。

is_linked #

is_linked method returns whether the V5 Brains on a MessageLink are paired with one another.

True – The two V5 Brains are paired and communicating on this link.
False – The two V5 Brains are not paired on this link.

**注意：**在项目开始时，运行任何其他代码之前，最好始终检查以确保 V5 Brains 已连接。

Usage:
link.is_linked()

参数	描述
	此方法没有参数。

机器人 1 的代码

# Tell the other robot when the screen is being pressed

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.MANAGER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

brain.screen.print("Robot 1 - Manager")

# Continuously send if the screen is being pressed
while True:
    if brain.screen.pressing():
        link.send("pressed")
    else:
        link.send("released")

    wait(50, MSEC)

机器人2的代码

# Display if the other robot's screen is being pressed

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.WORKER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

# Continuously check if Robot 1 has sent "pressed"
while True:
    brain.screen.clear_screen()
    brain.screen.set_cursor(1, 1)
    brain.screen.print("Robot 2 - Worker")
    brain.screen.next_row()

    if link.receive() == "pressed":
        brain.screen.new_line()
        brain.screen.print("Manager is being pressed!")

    wait(50, MSEC)

send #

send sends a string and/or an integer and/or float to the other linked V5 Brain.

Usage:
send(string, integer, float)

参数	描述
`string`	要发送给另一个已连接的 V5 大脑的字符串。
`integer`	可选。要发送给另一个已连接的 V5 大脑的整数。
`float`	可选。要发送到另一个已连接的 V5 Brain 的浮点数。浮点数默认显示 4 位小数；如果提供的位数少于 4 位，则会在末尾添加零，直到显示 4 位小数为止。

If only string is sent, the other linked V5 Brain receives that exact string.

If integer and/or float are included, the receiving Brain gets a single encoded string that combines all fields in this order: .string_integer_float

Example: Using link.send(“string”, 1, 2.55) is received as .string_1_2.5500.

机器人 1 的代码

# Tell the other robot when the screen is being pressed

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.MANAGER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

brain.screen.print("Robot 1 - Manager")

# Continuously send if the screen is being pressed
while True:
    if brain.screen.pressing():
        link.send("pressed")
    else:
        link.send("released")

    wait(50, MSEC)

机器人2的代码

# Display if the other robot's screen is being pressed

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.WORKER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

# Continuously check if Robot 1 has sent "pressed"
while True:
    brain.screen.clear_screen()
    brain.screen.set_cursor(1, 1)
    brain.screen.print("Robot 2 - Worker")
    brain.screen.next_row()

    if link.receive() == "pressed":
        brain.screen.new_line()
        brain.screen.print("Manager is being pressed!")

    wait(50, MSEC)

机器人 1 的代码

# Tell the other robot where the screen was pressed

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.MANAGER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

brain.screen.print("Robot 1 - Manager")
brain.screen.next_row()
brain.screen.print("Tap to send circles")

# Send the coordinates whenever the screen is pressed
while True:
    if brain.screen.pressing():
        x = brain.screen.x_position()
        y = brain.screen.y_position()

        link.send("touch", x, y)

    wait(10, MSEC)

机器人2的代码

# Draw a circle where Robot 1's screen was pressed

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.WORKER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

brain.screen.print("Robot 2 - Worker")

while True:
    # Get the full encoded string
    circle_coordinates = link.receive(200)

    if circle_coordinates:

        # Split the encoded string by _
        parts = circle_coordinates.split("_")

        if len(parts) == 3:
            # Convert the coordinates back into numbers
            x = float(parts[1])
            y = float(parts[2])

            brain.screen.set_fill_color(Color.WHITE)
            brain.screen.draw_circle(x, y, 20)

    wait(10, MSEC)

receive #

receive returns the next queued message from the other linked V5 Brain. Messages are read in FIFO order (oldest unread first). If the queue is empty when receive is called, it waits up to the specified timeout for a new message. If no message arrives in that window, receive returns None, and any message sent afterward remains in the queue to be read the next time receive is used.

If the other linked V5 Brain sent only a string, receive returns that exact string.

If the other linked V5 Brain sent an integer and/or float, receive returns a single encoded string that combines all fields in this order: .string_integer_float

For example, if the other linked V5 Brain uses link.send(“string”, 1, 2.55), then using link.receive() returns an encoded string such as .string_1_2.5500. You can split this encoded string (see the examples below) to extract the message name, integer, and float values.

If you’d rather avoid manual splitting/parsing, use received to register a handler for a specific message name; the handler receives the sent values as arguments.

Usage:
receive(timeout)

参数	描述
`timeout`	Optional. How long in milliseconds `receive` will wait for a new message only if the queue is empty. Default is 300,000 (300 seconds).

机器人 1 的代码

# Tell the other robot when the screen is being pressed

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.MANAGER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

brain.screen.print("Robot 1 - Manager")

# Continuously send if the screen is being pressed
while True:
    if brain.screen.pressing():
        link.send("pressed")
    else:
        link.send("released")

    wait(50, MSEC)

机器人2的代码

# Display if the other robot's screen is being pressed

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.WORKER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

# Continuously check if Robot 1 has sent "pressed"
while True:
    brain.screen.clear_screen()
    brain.screen.set_cursor(1, 1)
    brain.screen.print("Robot 2 - Worker")
    brain.screen.next_row()

    if link.receive() == "pressed":
        brain.screen.new_line()
        brain.screen.print("Manager is being pressed!")

    wait(50, MSEC)

机器人 1 的代码

# Send a math problem for the other Brain to solve

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.MANAGER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

brain.screen.print("Robot 1 - Manager")

"""
Change whether to "add" or "subtract",
then what numbers to use in the operation.
"""
link.send("add", 7, 2.5)

机器人2的代码

# Solve the math problem that the other Brain sends

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.WORKER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

brain.screen.print("Robot 2 - Worker")
brain.screen.next_row()

math_problem = link.receive()

if math_problem:

    # Split the encoded string by _
    parts = math_problem.split("_")

    if len(parts) == 3:
        # Remove the . from the beginning of the string
        operator = "".join([c for c in parts[0] if c.isalpha()])

        # Separate out the numbers for the operation
        a = int(parts[1])
        b = float(parts[2])

        # Use what operator was sent
        if operator == "add":
            result = a + b
        elif operator == "subtract":
            result = a - b
        # If neither add or subtract is sent, do nothing
        else:
            pass

brain.screen.print("Result = ", result)

received #

received registers a function to be called whenever the V5 Brain receives a sent message.

Usage:
link.received(message, arg)

参数	描述
`message`	The message name (string) to match. When a received message’s name matches this value, the `callback` function is called.
`callback`	A previously defined function that runs when the V5 Brain receives a message matching `message`.

received callbacks are called with four arguments:

Callback Signature:
callback(message, linkname, index, value)

争论	描述
`message`	The message name that was received (for example, `“add”`).
`linkname`	收到该消息的链接名称。
`index`	消息中发送的整数值（如果提供）。
`value`	消息中发送的浮点值（如果提供）。

机器人 1 的代码

# Send a math problem for the other Brain to solve

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.MANAGER)

# Do not run code UNTIL the Brains are linked
while not link.is_linked():
    wait(0.1, SECONDS)

brain.screen.print("Robot 1 - Manager")

"""
Change whether to "add" or "subtract",
then what numbers to use in the operation.
"""
link.send("add", 7, 2.5)

机器人2的代码

# Solve the math problem that the other Brain sends

# Create the link
link = MessageLink(Ports.PORT1, "VEXRoboticsLink123456789", VexlinkType.WORKER)

while not link.is_linked():
    wait(0.1, SECONDS)

brain.screen.print("Robot 2 - Worker")
brain.screen.next_row()

# add if "add" is received
def add_cmd(message, linkname, a, b):
    result = a + b
    brain.screen.print("Result = ", result)

# subtract if ""subtract" is received
def subtract_cmd(message, linkname, a, b):
    result = a - b
    brain.screen.print("Result = ", result)

# Create event handlers for "add" and "subtract"
link.received("add", add_cmd)
link.received("subtract", subtract_cmd)

消息链接#

介绍#

创建链接#

可用方法#

is_linked#

send#

receive#

received#

介绍 #

创建链接 #

可用方法 #

is_linked #

send #

receive #

received #