I have a Pycom Lopy 4 that will recieve sensor readings from another MCU and structure the received data before sending it on to an MQTT server. To achieved that, I initialised the WLAN mode of my LoPy4 to 'STA_AP'.
However, I realised that when i attempted a wlan.disconnect(), and my code enters a function block to deal with the data, wlan.isconnected() returns True again! I know this because I placed a few print statements within the function body to check for connectivity. Below is my code:
import usocket
from network import WLAN
import ustruct
from mqtt import MQTTClient
import machine
sensor_dict = {
0x77 : "bme280"
# Add more sensors here #
}
wlan = WLAN()
## Set static IP address for server
wlan.ifconfig(id = 1, config=('192.168.0.104', '255.255.255.0', '192.168.0.1', '192.168.0.1'))
## Set WLAN mode to STA_AP (station & access point)
print("Setting up wlan access point...")
wlan.init(mode = WLAN.STA_AP, ssid = 'server_layer1', auth = (WLAN.WPA2, 'Password123'), channel=7, antenna=WLAN.INT_ANT)
print("wlan mode set up: with WPA2 auth\n")
## -----------------------------This is the function block---------------------------------- ##
def send_data(data_raw):
print("Unpacking raw data...")
data = ustruct.unpack('lifff', data_raw)
loc, sensor_type, temp, press, hum = data
if wlan.isconnected():
print("connected1")
## Connect to internet
wlan.connect("Name", auth=(WLAN.WPA2, "hahahahaha"), timeout=5000)
if wlan.isconnected():
print("connected3")
while not wlan.isconnected():
machine.idle()
print("Connected to WiFi\n")
print("Sending data up to MQTT server...")
client = MQTTClient("xxx123", "io.adafruit.com",user="yoplo", password="xxx123", port=1883)
client.connect()
client.publish(topic="yoplo/feeds/{}/{}/temp".format(loc, sensor_dict[sensor_type]), msg=temp, retain = True)
## ---------------------------------End of function block------------------------------------- ##
UDP_IP = "0.0.0.0"
UDP_PORT = 6006
## Set up UDP socket and bind
sock = usocket.socket(usocket.AF_INET,usocket.SOCK_DGRAM) ## UDP
sock.bind((UDP_IP, UDP_PORT))
print('Socket binded.')
data_raw, addr = sock.recvfrom(24) ## buffer size is 24 bytes
## -----------------------------------ran wlan.disconnect() here--------------------------------##
wlan.disconnect()
if wlan.isconnected():
print("connected2")
send_data(data_raw)
machine.deepsleep(10)
My output was:
Setting up wlan access point...
wlan mode set up: with WPA2 auth
Socket binded.
raw data payload: b'q\x01\x00\x00w\x00\x00\x00\xe1z\xd0Aq\xedzD\x14\xae^B'
source: ('192.168.0.105', 49258)
connected2
Unpacking raw data...
connected1
connected3
Connected to WiFi
Sending data up to MQTT server...
Traceback (most recent call last):
File "main.py", line 65, in <module>
File "main.py", line 43, in send_data
File "/flash/lib/mqtt.py", line 66, in connect
OSError: [Errno 113] EHOSTUNREACH
Pycom MicroPython 1.18.2.r6 [v1.8.6-849-a210e85] on 2019-05-13; LoPy4 with ESP32
Type "help()" for more information.
'connected1' and 'connected3' were printed, although 'connected2' was not printed. Not sure why, appreciate any assistance!
Related
I use Raspberry Pi Pico with ESP8266 WiFi module, and I am trying to write a TCP client. Rasp Pi Pico is able to send AT commands and receive responses and send data through UART. Also the TCP client is able to send data to the TCP server, which runs in my laptop. However the problem is that the client is not able to connect to the server after some point.
Let me first show the server-side code. In server, I am trying to receive data basically. ConnectionResetError was a problem for me so I wrote the following except block. I am not sure it is buggy or not, since I'm kind of a noob in this area.
import socket
HOST = ""
PORT = 8080
mysocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
mysocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
mysocket.bind((HOST, PORT))
mysocket.listen(1)
while True:
print("Waiting...")
conn, addr = mysocket.accept()
print('[SERVER] - Connected from: %s' % str(addr))
while True:
try:
request = conn.recv(1024)
if not request:
break
conn.sendall(request.upper())
print('[SERVER] - Received Data: %s' % str(request))
except ConnectionResetError as cr_err:
break
conn.close()
print("[SERVER] - Disconnected")
Here is my client-side code. In client, I wrote two helper classes called ESP8266 and Sensor, in which I control the WiFi module and read analog value from a sensor. Pico first tries to start WiFi module, afterwards it tries to connect to TCP server and send data. After some point it does not connect to the TCP server, so it restart the WiFi module and reconnects.
class EndDevice:
def __init__(self, sensor_id):
self.__wifi_module = ESP8266(UART_PIN, BAUDRATE)
self.__sensor = Sensor(sensor_id, SENSOR_PIN)
def start(self):
self.__wifi_module.start()
self.__wifi_module.set_mode(STATION_MODE)
self.__wifi_module.join_access_point(AP_NAME, AP_PWD)
def reconnect(self):
self.__wifi_module.restart()
self.__wifi_module.set_mode(STATION_MODE)
self.__wifi_module.join_access_point(AP_NAME, AP_PWD)
def run(self):
retry_count = 0
while True:
if self.__wifi_module.start_connection("TCP", SERVER_HOST, SERVER_PORT):
self.__wifi_module.send_data(
str(self.__sensor.generate_package()))
self.__wifi_module.close_connection()
else:
retry_count += 1
if retry_count == MAX_RETRY:
break
if __name__ == "__main__":
pico = EndDevice("SM-0")
pico.start()
while True:
pico.run()
pico.reconnect()
Finally I will share some of the methods in classes ESP8266 and UARTHandler (which is used in ESP8266), so you can see if I do anything non-sense.
start_connection method in ESP8266 is as follows. In this method, I tried to send the corresponding AT command to connect to a TCP server. In the method self.__uart_handler.send_receive_cmd timeout duration is 2000ms, and other parameters are AT command, connection_type (TCP), server IP address and server port, in order.
def start_connection(self, conn_type, remote_ip, remote_port):
conn_type, remote_ip = "\"{}\"".format(conn_type), "\"{}\"".format(remote_ip)
response = self.__uart_handler.send_receive_cmd(2000, CONN_START, conn_type, remote_ip, str(remote_port))
if "OK" in response:
self.__log("Connected to {} at port {}.".format(remote_ip, remote_port))
return True
else:
self.__log("Failed to create a connection with {} at port {}.".format(remote_ip, remote_port))
return False
send_receive_cmd method in UARTHandler is as follows. In this method I use lots of helper methods as you can see, however they are just formatting and writing to UART or reading from UART. I also insert a timeout between UART-read and UART-write
def __generate_cmd(self, cmd, *args):
if len(args) != 0:
cmd += "="
for idx, each in enumerate(args):
cmd += str(each)
if idx != len(args)-1:
cmd += ","
cmd += "\r\n"
return cmd
def __send_cmd(self, cmd, *args):
sent_cmd = self.__generate_cmd(cmd, *args)
self.__uart.write(sent_cmd)
def __receive_response(self, cmd):
response = self.__uart.read()
try: return response.decode('utf-8')
except: return response
def send_receive_cmd(self, timeout, cmd, *args):
self.__send_cmd(cmd, *args)
utime.sleep_ms(timeout)
return self.__receive_response(self.__generate_cmd(cmd, *args))
Let me ask my question again. This codes are working properly in starting-restarting and sending data for (let me say) 3 connections. However, after some connect-disconnect later, TCP client is not able to make a connection with TCP server. Again after some failed connection attempt, WiFi module is restarted and TCP connection is made and working properly again.
I have set up a simple client-server communication code and it works well in my computer when my computer itself acts as a server and the client.
Now I am trying to run this same code on two different computers in different networks( different locations) where my computer will act as a server and my friend's computer as a client.
I have done port forwarding in my router as well as in my friend's router for the port which we are trying to communicate. We both have set up a static IP in our internal network behind the router. We both had shutdown the firewall while running the code.
I am running my code on Jupiter notebook and the same is my friend too.
here is my server code:
import socket
import threading
HEADER = 64
PORT = 5064
SERVER = '0.0.0.0'
ADDR = (SERVER, PORT)
FORMAT = 'utf-8'
DISCONNECT_MESSAGE = "quit"
Receive_from_client = "get info"
server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
server.bind(ADDR)
def handle_client(conn, addr):
print("\n" + f"[NEW Connection] detected from IP: {addr[0]} & Port:{addr[1]} ")
conn.send(f"connected to server {ADDR}".encode(FORMAT))
connected =True
while connected:
msg_length = conn.recv(HEADER).decode(FORMAT) # decode the msg from byte to utf-8 format
if msg_length:
msg_length = int(msg_length)
msg = conn.recv(msg_length).decode(FORMAT)
if msg == DISCONNECT_MESSAGE:
connected = False
print(f" [Client][{addr}] {msg}")
print("Your session is disconnected")
break
if msg == Receive_from_client:
print("\n" + f"Send your msg to client with IP: {addr[0]}")
thread = threading.Thread(target = send2client, args = (conn, addr))
thread.start()
print(f" [Client][{addr}] {msg}")
conn.send(f"Msg received by server with IP:{addr[0]}".encode(FORMAT))
conn.close()
server.close()
def start():
server.listen()
print("\n"+ f"[LISTENING] Server is listening from IP: {SERVER} ")
while True:
conn, addr = server.accept()
thread = threading.Thread(target = handle_client, args = (conn, addr))
thread.start()
Here is the client code
import socket
import threading
HEADER = 64
PORT = 5064
FORMAT = 'utf-8'
DISCONNECT_MESSAGE = "quit"
SERVER = '103.192.207.250' # SERVERS public IP
ADDR = (SERVER, PORT)
client = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
client.connect(ADDR)
def send2server():
while True:
msg = input()
message = msg.encode(FORMAT)
msg_lenght = len(message)
send_length = str(msg_lenght).encode(FORMAT)
send_length += b' '*(HEADER - len(send_length))
client.send(send_length)
client.send(message)
print(client.recv(2048).decode(FORMAT))
if msg == DISCONNECT_MESSAGE:
print("session closed")
client.close()
def start():
print("\n"+ f"[LISTENING] client is listening from IP: {ADDR} ")
send2server()
I have opened the port by going on windows firewall defender and selecting new inbound and outbound rules to open 5064 TCP port.
but still, the code doesn't works..
my server keeps waiting for connection and the client-side after few seconds of running gives this error:
TCP error code 10060: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond
Even while my server is listening from port 5064 when I scan this port to check if the port is open or not it says closed.
How do I check if the port I have forwarded is for sure open and also how do I get this thing work?
I have tried all of this and if there is any other thing I am missing please tell. I am struggling to get this work for the past 3 days.
I am using micropython on my esp32. I want to send data from esp32 to AWS IoT MQTT Broker Endpoint.
But in micropython socket module, getaddrinfo(hostname, port) method return empty list every time. How can I solve it?
It is working when I use IP address instead of host name. But AWS MQTT broker endpoint has no static IP for its broker endpoint.
# My code:
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect("wifiname", "password")
KEY_PATH = "/619e3d582c-private.pem.key"
CERT_PATH = "/619e3d582c-certificate.pem"
with open(KEY_PATH, 'r') as f:
PVT_KEY = f.read()
with open(CERT_PATH, 'r') as f:
CERT_KEY = f.read()
client = MQTTClient(client_id="esp32_micropython_shafik",
server="xxxxxxxxxxx.iot.eu-west-1.amazonaws.com",
port = 8883,
keepalive = 10000,
ssl = True,
ssl_params = {
"cert": CERT_KEY,
"key": PVT_KEY,
"server_side":False
} )
def checkwifi():
while not sta_if.isconnected():
time.sleep_ms(500)
print(".")
sta_if.connect()
def publish():
while True:
checkwifi()
msg = b'hello shafik'
client.publish(b"weather", msg)
time.sleep(1)
print("type", type(PVT_KEY))
client.connect()
publish()`
I am getting continuously this error:
umqtt/simple.py in 57 line,
IndexError: list index out of range.
How can I solve it?
I have solved this problem just changing my wifi network.
Actually this problem occurred for my ISP network issue, that's why socket module didn't work properly for fetching IP address properly.
I met an error when running codes at the bottom. It's like a simple ftp.
I use python2.6.6 and CentOS release 6.8
In most linux server, it gets right results like this:(I'm very sorry that I have just sign up and couldn't )
Clinet:
[root#Test ftp]# python client.py
path:put|/home/aaa.txt
Server:
[root#Test ftp]# python server.py
connected...
pre_data:put|aaa.txt|4
cmd: put
file_name: aaa.txt
file_size: 4
upload successed.
But I get errors in some server(such as my own VM in my PC). I have done lots of tests(python2.6/python2.7, Centos6.5/Centos6.7) and found this error is not because them. Here is the error imformation:
[root#Lewis-VM ftp]# python server.py
connected...
pre_data:put|aaa.txt|7sdfsdf ###Here gets the wrong result, "sdfsdf" is the content of /home/aaa.txt and it shouldn't be sent here to 'file_size' and so it cause the "ValueError" below
cmd: put
file_name: aaa.txt
file_size: 7sdfsdf
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 10699)
Traceback (most recent call last):
File "/usr/lib64/python2.6/SocketServer.py", line 570, in process_request_thread
self.finish_request(request, client_address)
File "/usr/lib64/python2.6/SocketServer.py", line 332, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/usr/lib64/python2.6/SocketServer.py", line 627, in __init__
self.handle()
File "server.py", line 30, in handle
if int(file_size)>recv_size:
ValueError: invalid literal for int() with base 10: '7sdfsdf\n'
What's more, I found that if I insert a time.sleep(1) between sk.send(cmd+"|"+file_name+'|'+str(file_size)) and sk.send(data) in client.py, the error will disappear. I have said that I did tests in different system and python versions and the error is not because them. So I guess that is it because of some system configs? I have check about socket.send() and socket.recv() in python.org but fount nothing helpful. So could somebody help me to explain why this happend?
The code are here:
#!/usr/bin/env python
#coding:utf-8
################
#This is server#
################
import SocketServer
import os
class MyServer(SocketServer.BaseRequestHandler):
def handle(self):
base_path = '/home/ftp/file'
conn = self.request
print 'connected...'
while True:
#####receive pre_data: we should get data like 'put|/home/aaa|7'
pre_data = conn.recv(1024)
print 'pre_data:' + pre_data
cmd,file_name,file_size = pre_data.split('|')
print 'cmd: ' + cmd
print 'file_name: '+ file_name
print 'file_size: '+ file_size
recv_size = 0
file_dir = os.path.join(base_path,file_name)
f = file(file_dir,'wb')
Flag = True
####receive 1024bytes each time
while Flag:
if int(file_size)>recv_size:
data = conn.recv(1024)
recv_size+=len(data)
else:
recv_size = 0
Flag = False
continue
f.write(data)
print 'upload successed.'
f.close()
instance = SocketServer.ThreadingTCPServer(('127.0.0.1',9999),MyServer)
instance.serve_forever()
#!/usr/bin/env python
#coding:utf-8
################
#This is client#
################
import socket
import sys
import os
ip_port = ('127.0.0.1',9999)
sk = socket.socket()
sk.connect(ip_port)
while True:
input = raw_input('path:')
#####we should input like 'put|/home/aaa.txt'
cmd,path = input.split('|')
file_name = os.path.basename(path)
file_size=os.stat(path).st_size
sk.send(cmd+"|"+file_name+'|'+str(file_size))
send_size = 0
f= file(path,'rb')
Flag = True
#####read 1024 bytes and send it to server each time
while Flag:
if send_size + 1024 >file_size:
data = f.read(file_size-send_size)
Flag = False
else:
data = f.read(1024)
send_size+=1024
sk.send(data)
f.close()
sk.close()
The TCP is a stream of data. That is the problem. TCP do not need to keep message boundaries. So when a client calls something like
connection.send("0123456789")
connection.send("ABCDEFGHIJ")
then a naive server like
while True;
data = conn.recv(1024)
print data + "_"
may print any of:
0123456789_ABCDEFGHIJ_
0123456789ABCDEFGHIJ_
0_1_2_3_4_5_6_7_8_9_A_B_C_D_E_F_G_H_I_J_
The server has no chance to recognize how many sends client called because the TCP stack at client side just inserted data to a stream and the server must be able to process the data received in different number of buffers than the client used.
Your server must contain a logic to separate the header and the data. All of application protocols based on TCP use a mechanism to identify application level boundaries. For example HTTP separates headers and body by an empty line and it informs about the body length in a separate header.
Your program works correctly when server receives a header with the command, name and size in a separate buffer it it fails when client is fast enough and push the data into stream quickly and the server reads header and data in one chunk.
So I am working on an iPhone app that requires a socket to handle multiple clients for online gaming. I have tried Twisted, and with much effort, I have failed to get a bunch of info to be sent at once, which is why I am now going to attempt socket.
My question is, using the code below, how would you be able to have multiple clients connected? I've tried lists, but I just can't figure out the format for that. How can this be accomplished where multiple clients are connected at once and I am able to send a message to a specific client?
Thank you!
#!/usr/bin/python # This is server.py file
import socket # Import socket module
s = socket.socket() # Create a socket object
host = socket.gethostname() # Get local machine name
port = 50000 # Reserve a port for your service.
print 'Server started!'
print 'Waiting for clients...'
s.bind((host, port)) # Bind to the port
s.listen(5) # Now wait for client connection.
c, addr = s.accept() # Establish connection with client.
print 'Got connection from', addr
while True:
msg = c.recv(1024)
print addr, ' >> ', msg
msg = raw_input('SERVER >> ')
c.send(msg);
#c.close() # Close the connection
Based on your question:
My question is, using the code below, how would you be able to have multiple clients connected? I've tried lists, but I just can't figure out the format for that. How can this be accomplished where multiple clients are connected at once and I am able to send a message to a specific client?
Using the code you gave, you can do this:
#!/usr/bin/python # This is server.py file
import socket # Import socket module
import thread
def on_new_client(clientsocket,addr):
while True:
msg = clientsocket.recv(1024)
#do some checks and if msg == someWeirdSignal: break:
print addr, ' >> ', msg
msg = raw_input('SERVER >> ')
#Maybe some code to compute the last digit of PI, play game or anything else can go here and when you are done.
clientsocket.send(msg)
clientsocket.close()
s = socket.socket() # Create a socket object
host = socket.gethostname() # Get local machine name
port = 50000 # Reserve a port for your service.
print 'Server started!'
print 'Waiting for clients...'
s.bind((host, port)) # Bind to the port
s.listen(5) # Now wait for client connection.
print 'Got connection from', addr
while True:
c, addr = s.accept() # Establish connection with client.
thread.start_new_thread(on_new_client,(c,addr))
#Note it's (addr,) not (addr) because second parameter is a tuple
#Edit: (c,addr)
#that's how you pass arguments to functions when creating new threads using thread module.
s.close()
As Eli Bendersky mentioned, you can use processes instead of threads, you can also check python threading module or other async sockets framework. Note: checks are left for you to implement how you want and this is just a basic framework.
accept can continuously provide new client connections. However, note that it, and other socket calls are usually blocking. Therefore you have a few options at this point:
Open new threads to handle clients, while the main thread goes back to accepting new clients
As above but with processes, instead of threads
Use asynchronous socket frameworks like Twisted, or a plethora of others
Here is the example from the SocketServer documentation which would make an excellent starting point
import SocketServer
class MyTCPHandler(SocketServer.BaseRequestHandler):
"""
The RequestHandler class for our server.
It is instantiated once per connection to the server, and must
override the handle() method to implement communication to the
client.
"""
def handle(self):
# self.request is the TCP socket connected to the client
self.data = self.request.recv(1024).strip()
print "{} wrote:".format(self.client_address[0])
print self.data
# just send back the same data, but upper-cased
self.request.sendall(self.data.upper())
if __name__ == "__main__":
HOST, PORT = "localhost", 9999
# Create the server, binding to localhost on port 9999
server = SocketServer.TCPServer((HOST, PORT), MyTCPHandler)
# Activate the server; this will keep running until you
# interrupt the program with Ctrl-C
server.serve_forever()
Try it from a terminal like this
$ telnet localhost 9999
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Hello
HELLOConnection closed by foreign host.
$ telnet localhost 9999
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Sausage
SAUSAGEConnection closed by foreign host.
You'll probably need to use A Forking or Threading Mixin too
This program will open 26 sockets where you would be able to connect a lot of TCP clients to it.
#!usr/bin/python
from thread import *
import socket
import sys
def clientthread(conn):
buffer=""
while True:
data = conn.recv(8192)
buffer+=data
print buffer
#conn.sendall(reply)
conn.close()
def main():
try:
host = '192.168.1.3'
port = 6666
tot_socket = 26
list_sock = []
for i in range(tot_socket):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR,1)
s.bind((host, port+i))
s.listen(10)
list_sock.append(s)
print "[*] Server listening on %s %d" %(host, (port+i))
while 1:
for j in range(len(list_sock)):
conn, addr = list_sock[j].accept()
print '[*] Connected with ' + addr[0] + ':' + str(addr[1])
start_new_thread(clientthread ,(conn,))
s.close()
except KeyboardInterrupt as msg:
sys.exit(0)
if __name__ == "__main__":
main()
def get_clients():
first_run = True
startMainMenu = False
while True:
if first_run:
global done
done = False
Thread(target=animate, args=("Waiting For Connection",)).start()
Client, address = objSocket.accept()
global menuIsOn
if menuIsOn:
menuIsOn = False # will stop main menu
startMainMenu = True
done = True
# Get Current Directory in Client Machine
current_client_directory = Client.recv(1024).decode("utf-8", errors="ignore")
# beep on connection
beep()
print(f"{bcolors.OKBLUE}\n***** Incoming Connection *****{bcolors.OKGREEN}")
print('* Connected to: ' + address[0] + ':' + str(address[1]))
try:
get_client_info(Client, first_run)
except Exception as e:
print("Error data received is not a json!")
print(e)
now = datetime.now()
current_time = now.strftime("%D %H:%M:%S")
print("* Current Time =", current_time)
print("* Current Folder in Client: " + current_client_directory + bcolors.WARNING)
connections.append(Client)
addresses.append(address)
if first_run:
Thread(target=threaded_main_menu, daemon=True).start()
first_run = False
else:
print(f"{bcolors.OKBLUE}* Hit Enter To Continue.{bcolors.WARNING}\n#>", end="")
if startMainMenu == True:
Thread(target=threaded_main_menu, daemon=True).start()
startMainMenu = False
#!/usr/bin/python
import sys
import os
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
port = 50000
try:
s.bind((socket.gethostname() , port))
except socket.error as msg:
print(str(msg))
s.listen(10)
conn, addr = s.accept()
print 'Got connection from'+addr[0]+':'+str(addr[1]))
while 1:
msg = s.recv(1024)
print +addr[0]+, ' >> ', msg
msg = raw_input('SERVER >>'),host
s.send(msg)
s.close()