BeagleBone与电脑Socket通信异常：回传数据报WinError 10057错误

已实现BeagleBone向电脑发送数据，但电脑向BeagleBone回传时出现以下错误：

Socket created
Socket bind complete
Socket now listening
Connected to 192.168.0.120:49378
main:: Begin program...
Residual System Status: startup

Please address errors. Continue? (Y/N) 

y
Traceback (most recent call last):

  File ~\Desktop\miles_lybrairy\milesintegration_V0.0.3\MILES\sockettoem.py:41 in <module>
    s.send(bytes(input(),'UTF-8'))

OSError: [WinError 10057] A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied

BeagleBone端代码 #

import Adafruit_BBIO.ADC as ADC
import time
import socket
import sys
import os

serverAddr = ('192.168.0.11', 20103)

client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client.connect(serverAddr)

fsr = 'P9_40'

ADC.setup()

while True:
        reading = ADC.read(fsr)*1000
        reading = int(round(reading))
        stdout =os.system("python3 ./fw102c_control.py")
        
        #client.send(bytes("poop"))
        client.recv(1024)
client.close()

电脑端代码 #

# -*- coding: utf-8 -*-
"""
Created on Mon Aug 15 13:56:19 2022

@author: GigaGame
"""


import socket
import sys
import os

HOST = ''
PORT = 20103



s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print('Socket created')

try:
        s.bind((HOST, PORT))
except socket.error as msg:
        print('Bind failed. ')
        sys.exit()

print('Socket bind complete')


s.listen(10)
print('Socket now listening')

conn, addr = s.accept()
print('Connected to ' + addr[0] + ':' + str(addr[1]))

while True:
        
        data = conn.recv(1024)
        line = data.decode('UTF-8')    # convert to string (Python 3 only)
        print( line )

        s.send(bytes(input(),'UTF-8'))
        #s.recv()

问题原因及解决办法 #

核心问题 #

电脑端代码中，你使用了监听socket s来发送数据，但TCP协议中，监听socket仅用于接受客户端连接，真正和BeagleBone通信的是accept()返回的连接socket conn。直接调用s.send()会触发WinError 10057，因为监听socket本身未与任何客户端建立连接。

修改步骤 #

1. 修正电脑端发送逻辑：
   将电脑端循环内的s.send(bytes(input(),'UTF-8'))改为conn.send(bytes(input(),'UTF-8'))，改用连接socket发送数据。

2. 完善BeagleBone端数据发送逻辑：
   当前BB端仅等待接收数据，未主动发送内容，会导致电脑端conn.recv(1024)长期阻塞，无法进入发送环节。可取消注释client.send(bytes("poop"))，或发送采集到的FSR数据，例如：

   client.send(str(reading).encode('UTF-8'))
   

修改后的电脑端关键代码片段 #

while True:
        data = conn.recv(1024)
        if not data:  # 处理客户端断开连接的情况
            break
        line = data.decode('UTF-8')
        print( line )

        # 使用连接socket发送回传数据
        conn.send(bytes(input(),'UTF-8'))

修改后的BeagleBone端关键代码片段 #

while True:
        reading = ADC.read(fsr)*1000
        reading = int(round(reading))
        stdout = os.system("python3 ./fw102c_control.py")
        
        # 主动发送采集数据到电脑
        client.send(str(reading).encode('UTF-8'))
        # 接收电脑回传内容
        response = client.recv(1024)
        print("Received from PC:", response.decode('UTF-8'))

内容的提问来源于stack exchange，提问作者Munix0