3.2. Multi-device Communication¶

multi_comm_ctrl.set_group(send_group, recv_group_list)¶

Example description:
Description:	Sets the group number of the device to `send_group`, and the device can receive messages from the group numbers registered in `recv_group_list`. If the ``recv_group_list’’ parameter is not used, messages from group 0 will be received by default.
Parameters:	send_group (int) – The sending group number of the current device. The default group number is 0. recv_group_list (list/tuple) – The current list of groups that receive messages, whose type can be list or tuple
Returns:	None
Example:	`multi_comm_ctrl.set_group(1, (1,2,3))`
	Set the current sending group number to 1 and receive messages from groups 1, 2, and 3. If the receiving group includes the sending group, you will receive the messages you send.

multi_comm_ctrl.send_msg(msg, group)¶

Example description:
Description:	Send a message via multi-device communication. Sending groups for this message can be set separately.
Parameters:	msg (int) – The message that needs to be sent group (int) – An optional parameter, which specifies the current message sending group number. If you do not specify this parameter, the previously set group number will be used by default.
Returns:	None
Example:	`multi_comm_ctrl.send_msg('RoboMaster EP', 3)`
	Send the `'RoboMaster EP'` message to group 3

multi_comm_ctrl.recv_msg(timeout)¶

Example description:
Description:	Receive messages (valid when recv_callback is not registered). You can set a timeout period.
Parameters:	timeout (int) – The waiting time, which indicates the waiting time of the receiving function, whose accuracy is 1 second. The default value of this parameter is 72 seconds.
Returns:	`<msg_group>, <msg>`, which is the group number of the message sender and the content of the message
Example:	`group, recv_msg = multi_comm_ctrl.recv_msg(30)`
	Receive the message with a waiting time of 30 seconds, where “group” is the group number of the message sender, and “msg” is the content of the received message

multi_comm_ctrl.register_recv_callback(callback)¶

Description:	Registers the callback function for receiving messages. When a message is received, the callback function is run automatically.
Parameters:	callback (function) – The callback function to be registered. The prototype of the callback function is `def callback(msg)`, where the type of the `msg` parameter is the `(msg_group, msg)` tuple.
Returns:	None
Example:

#Define a function and register it as a callback function for receiving messages

def recv_callback(msg):
    pass

multi_comm_ctrl.register_recv_callback(recv_callback)

Hint

For a description of the module, refer to Multi-device Communication.