信息

介绍

两个 VEX AIM 编码机器人可以连接，以便在项目期间进行通信。通过消息功能，机器人可以发送和接收信息，协调彼此的动作。

**注意：**为了发送和接收消息，两个机器人必须同时运行处理消息的项目。

以下是可用方法的列表：

操作——在机器人之间发送消息。

• send_message – Sends a string and up to three numbers to the other linked robot.

Getters – 检查收到的消息和连接状态。

• get_message – Retrieve the most recent string received.

• get_message_and_data – Retrieve the most recent string and numbers received as a tuple.

• is_connected – Returns a Boolean indicating whether the robot is linked with another robot.

• is_message_available – Returns a Boolean indicating whether the other linked robot has ever sent a message.

回调——事件发生时运行函数。

• handle_message – Register a function to be called when a specific message is received.

• connected – Register a function to be called when the robot is connected with another robot.

• disconnected – Register a function to be called when the robot is disconnected with another robot.

行动

send_message

send_message sends a string and up to three numbers to the other linked robot.

Usage:
robot.link.send_message(message, arg1, arg2, arg3)

范围	描述
message	The string to send to the other linked robot.
arg1	可选。要发送给其他链接机器人的浮点数或整数。
arg2	可选。要发送给另一个链接机器人的第二个浮点数或整数。
arg3	可选。要发送给另一个链接机器人的第三个浮点数或整数。

Code for Robot 1

# Press the screen to tell Robot 2 which way to turn
robot.screen.print("Robot 1")
while not robot.screen.pressing():
    wait(5, MSEC)

# "right" turns right, "left" turns left
robot.link.send_message("right")

Code for Robot 2

# Turn in the direction that Robot 1 sends
robot.screen.print("Robot 2")
while not robot.link.is_message_available():
    wait(5, MSEC)
direction = robot.link.get_message()

if direction == "left":
    robot.turn_for(LEFT, 90)
elif direction == "right":
    robot.turn_for(RIGHT, 90)

---

Code for Robot 1

# Continuously send the current heading to Robot 2
robot.screen.print("Robot 1")
while True:
    robot.link.send_message("Turn to heading", robot.inertial.get_heading())
    wait(5, MSEC)

Code for Robot 2

# Turn to match Robot 1's heading
robot.screen.print("Robot 2")
while True:
    if robot.link.is_message_available():
        message, heading = robot.link.get_message_and_data()
        robot.turn_to(heading)   
    wait(5, MSEC)

---

Code for Robot 1

robot.screen.show_aivision()
while True:
    # Only return a max of 3 AprilTag IDs for message limit
    detections = robot.vision.get_data(ALL_TAGS, 3)

    # Identify the IDs collected
    ids = [det.id for det in detections]

    # Send IDs as separate arguments
    robot.link.send_message("Vision Data", *ids)
    # Tuple organized like: ("Vision Data", ID 1, ID 2, ID 3)

    wait(50, MSEC)

Code for Robot 2

while True:
    if robot.link.is_message_available():
        # Receive the message from Robot 1
        data = robot.link.get_message_and_data()

        # Separate out the received message
        message = data[0]
        arg1 = data[1] if len(data) > 1 else None
        arg2 = data[2] if len(data) > 2 else None
        arg3 = data[3] if len(data) > 3 else None

        # Reset the screen
        robot.screen.clear_screen()
        robot.screen.set_cursor(1, 1)
        robot.screen.print("Detected IDs:")
        robot.screen.next_row()

        # Display any IDs that exist from the data
        if message == "Vision Data":
            for tag_id in (arg1, arg2, arg3):
                if tag_id is not None:
                    robot.screen.print(tag_id)
                    robot.screen.next_row()

    wait(50, MSEC)

吸气剂

get_message

get_message returns the most recent string received from the other linked robot.

Usage:
robot.link.get_message(timeout)

参数	描述
timeout	可选。函数在没有消息的情况下继续执行之前等待消息的最长时间（以毫秒为单位）。默认值为 1000。

Code for Robot 1

# Press the screen to send a message to Robot 2
robot.screen.print("Robot 1")
while not robot.screen.pressing():
    wait(5, MSEC)

# Change the string to display a different message
robot.link.send_message("Hello, Robot 2!")

Code for Robot 2

# Display what message Robot 1 sends
robot.screen.print("Robot 2")
robot.screen.next_row()
while not robot.link.is_message_available():
    wait(5, MSEC)
message = robot.link.get_message()

robot.screen.print(message)

get_message_and_data

get_message_and_data returns the most recent string and numbers received from the other linked robot and returns it as a tuple.

Usage:
robot.link.get_message_and_data(timeout)

参数	描述
timeout	可选。函数在没有消息的情况下继续执行之前等待消息的最长时间（以毫秒为单位）。默认值为 1000。

Code for Robot 1

# Code for Robot 1

# Continuously send the current heading to Robot 2
robot.screen.print("Robot 1")
while True:
    robot.link.send_message("Turn to heading", robot.inertial.get_heading())
    wait(5, MSEC)

Code for Robot 2

# Turn to match Robot 1's heading
robot.screen.print("Robot 2")
while True:
    if robot.link.is_message_available():
        message, heading = robot.link.get_message_and_data()
        robot.turn_to(heading)   
    wait(5, MSEC)

is_connected

is_connected returns a Boolean indicating whether the robot is currently linked with another robot.

• True - The robot is linked with another robot.

• False - The robot is not linked with another robot.

Usage:
robot.link.is_connected()

参数	描述
	该方法没有参数。

# Turn off one of the linked robots to see the message change
while True:
    robot.screen.clear_screen(1, 1)
    robot.screen.print(robot.link.is_connected())
    wait(5, MSEC)

is_message_available

is_message_available returns a Boolean indicating whether the other linked robot has ever used send_message yet in the current project.

• True - send_message has been used by the other linked robot in the current project.

• False - send_message has never been used by the other linked robot in the current project.

Usage:
robot.link.is_message_available()

参数	描述
	该方法没有参数。

Code for Robot 1

# Press the screen to send a message to Robot 2
robot.screen.print("Robot 1")
while not robot.screen.pressing():
    wait(5, MSEC)

# Change the string to display a different message
robot.link.send_message("Hello, Robot 2!")

Code for Robot 2

# Display what message Robot 1 sends
robot.screen.print("Robot 2")
robot.screen.next_row()
while not robot.link.is_message_available():
    wait(5, MSEC)
message = robot.link.get_message()

robot.screen.print(message)

回调

handle_message

handle_message registers a method that runs when the robot receives a specific message string.

Usage:
robot.link.handle_message(callback, message)

参数	描述
callback	当收到的消息与指定的字符串匹配时调用的先前定义的函数。
message	The string to check incoming messages against. If it matches, the callback runs.

Code for Robot 1

# Press the screen to send a message to Robot 2
robot.screen.print("Robot 1")
while not robot.screen.pressing():
    wait(5, MSEC)

robot.link.send_message("smile")

Code for Robot 2

# Show a smiling emoji
def robot_smile():
    robot.screen.show_emoji(HAPPY)

# If Robot 1 sends "smile", show a smiling emoji
robot.screen.print("Robot 2")
while not robot.link.is_message_available():
    wait(5, MSEC)

robot.link.handle_message(robot_smile, "smile")

connected

connected registers a function to be called when the robot is linked to another robot.

Usage:
robot.link.connected(callback, args)

参数	描述
callback	当机器人链接到另一个机器人时调用的先前定义的函数。
args	可选。包含要传递给回调函数的参数的元组。更多信息请参阅使用带参数的函数。

# Show a happy face when connected
def robot_smile():
    robot.screen.show_emoji(HAPPY)

# Show a sad face when disconnected
def robot_sad():
    robot.screen.show_emoji(SAD)

# Register both callbacks
# Turn off a robot to change the emoji
robot.link.connected(robot_smile)
robot.link.disconnected(robot_sad)

disconnected

disconnected registers a function to be called when the robot is not linked to another robot.

Usage:
robot.link.disconnected(callback, args)

参数	描述
callback	当机器人未链接到另一个机器人时调用的先前定义的函数。
args	可选。包含要传递给回调函数的参数的元组。更多信息请参阅使用带参数的函数。

# Show a happy face when connected
def robot_smile():
    robot.screen.show_emoji(HAPPY)

# Show a sad face when disconnected
def robot_sad():
    robot.screen.show_emoji(SAD)

# Register both callbacks
# Turn off a robot to change the emoji
robot.link.connected(robot_smile)
robot.link.disconnected(robot_sad)