訊息連結#

介紹 #

MessageLink 允許兩個 EXP Brain 透過發送帶有可選少量資料的短字串訊息進行通訊。它專為機器人之間的協調而設計，例如啟動程式、共享感測器結果或觸發另一個機器人的行為。

每次使用 send 都會在關聯的 EXP Brain 的佇列中加入一則訊息，佇列採用先進先出 (FIFO) 的讀取方式。如果在另一個 EXP Brain 使用 receive 之前發送了多個訊息，這些訊息將被存儲，並按發送順序逐條返回。由於訊息可以排隊，因此在每次循環中重複發送相同的狀態可能會導致積壓；對於時間關鍵型邏輯，僅當值發生變化時才發送訊息。

重要提示：兩個機器人必須同時執行使用 MessageLink 項目，否則將不會發送/接收任何訊息。

本頁面使用 link 作為範例連結 MessageLink 名稱。請根據需要將其替換為您自己配置的名稱。

以下是可用方法清單：

is_linked – 傳回此大腦是否與其配對的大腦處於活動連結狀態。
send – 向配對的大腦發送訊息。
receive – 等待並傳回下一個傳入的訊息。
received – 註冊一個函數，每當收到新訊息時呼叫函數。

建立連結 #

在兩個 EXP 大腦上創建 MessageLink，以在它們之間建立通訊通道——可以透過 V5 機器人無線電進行無線連接，也可以透過有線智慧電纜進行連接——以便機器人可以互相發送訊息。

MessageLink(smartport, name, linktype, wired)

範圍	描述
`smartport`	此連接使用的智慧型連接埠－V5 機器人無線電連接的連接埠（無線）或智慧電纜插入的連接埠（有線）。格式為 `Ports.PORTx` ，其中 x 為連接埠號碼。
`name`	此連結的唯一名稱（字串形式）注意：此名稱應足夠長，以產生唯一的 ID，避免與其他團隊的連結意外匹配。
`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 EXP Brains are connected via a Smart Cable. `False` (default) – The EXP Brains connect wirelessly using V5 Robot Radios.

機器人 1 的程式碼

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

機器人2的程式碼

"""
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 設定完畢且 Brains 連線成功，您就可以使用以下方法傳送、接收和回覆訊息。

is_linked #

is_linked 方法傳回 MessageLink 上的 EXP Brains 是否彼此配對。

True – 兩個 EXP 大腦已配對並透過此連結進行通訊。
False – 此連結中的兩個 EXP 大腦並未配對。

注意：在專案開始時，運行任何其他程式碼之前，最好始終檢查以確保 EXP Brains 已連接。

Usage:
link.is_linked()

參數	描述
	此方法沒有參數。

機器人 1 的程式碼

# 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)

機器人2的程式碼

# 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 向另一個連接的 EXP Brain 發送字串和/或整數和/或浮點數。

Usage:
send(string, integer, float)

參數	描述
`string`	要傳送給另一個已連接的EXP Brain的字串。
`integer`	可選。要傳送給另一個已連接的經驗大腦的整數。
`float`	可選。要傳送給另一個已連接的 EXP Brain 的浮點數。浮點數預設顯示 4 位小數；如果提供的位數少於 4 位，則會在末尾添加零，直到顯示 4 位小數為止。

如果只傳送字串 string ，則另一個連接的 EXP Brain 將收到該字串。

如果包含 integer 和/或 float ，則接收端 Brain 將獲得一個按以下順序組合所有欄位的單一編碼字串： .string_integer_float

範例： 使用 link.send(“string”, 1, 2.55) 被接收為 .string_1_2.5500。

機器人 1 的程式碼

# 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)

機器人2的程式碼

# 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)

機器人 1 的程式碼

# 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)

機器人2的程式碼

# 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 傳回來自另一個已連線的 EXP Brain 的下一封已排隊的訊息。訊息以先進先出 (FIFO) 順序讀取（最舊的未讀訊息優先）。如果在呼叫 receive 時隊列為空，則會等待最多 receive 時間以接收新訊息。如果在該時間內沒有訊息到達， receive 返回 None，之後發送的任何訊息都將保留在佇列中，以便在下次使用 timeout 時讀取。

如果另一個連結的 EXP Brain 只發送了字串 string receive 回傳該字串。

如果另一個關聯的 EXP Brain 發送的是整數和/或浮點數， receive 傳回編碼字串，該字串會依以下順序組合所有欄位： .string_integer_float

例如，如果另一個連結的 EXP Brain 使用 link.send(“string”, 1, 2.55)，那麼使用 link.receive() 將傳回一個編碼字串，例如 .string_1_2.5500您可以拆分此編碼字串（請參閱下面的範例）以提取訊息名稱、整數和浮點值。

如果您不想手動分割/解析，請使用 received 為特定訊息名稱註冊處理程序；處理程序接收傳送的值作為參數。

Usage:
receive(timeout)

參數	描述
`timeout`	可選。等待新訊息的毫秒數 `receive` 表示佇列為空）。預設值為 300,000（300 秒）。

機器人 1 的程式碼

# 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)

機器人2的程式碼

# 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)

機器人 1 的程式碼

# 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)

機器人2的程式碼

# 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 註冊一個函數，每當 EXP Brain 收到發送的訊息時，函數將會被呼叫。

Usage:
link.received(message, arg)

參數	描述
`message`	The message name (string) to match. When a received message’s name matches this value, the `callback` function is called.
`callback`	先前定義的函數在 EXP Brain 收到與訊息 `message`相符的訊息時執行。

received 回呼被調用，並帶有四個參數：

回呼函數簽章：
callback(message, linkname, index, value)

爭論	描述
`message`	收到的訊息名稱（例如， `“add”`）。
`linkname`	收到該訊息的連結名稱。
`index`	訊息中發送的整數值（如果提供）。
`value`	訊息中發送的浮點值（如果提供）。

機器人 1 的程式碼

# 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)

機器人2的程式碼

# 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)

訊息連結#

介紹#

建立連結#

可用方法#

is_linked#

send#

receive#

received#

介紹 #

建立連結 #

可用方法 #

is_linked #

send #

receive #

received #