I am writing a python code on ESP8266 using MicroPython to configure it as STA, connect it to an AccessPoint and then send some data on UDP Socket.
I want to implement a scenario where in case if AccessPoint due to some reason goes down and comes back after some time, the the ESP8266 acting as STA should automatically reconnect to specific AP.
I am not sure if there's a functionality to setup a callback on STA if it misses few Beacons (e.g. upto 5 or 10)
This is the code that I have written so far:
import network
import esp
import gc
import time
try:
import usocket as socket
except ModuleNotFoundError as e:
import socket
def main():
count = 0
esp.osdebug(None)
gc.collect()
sta = network.WLAN(network.STA_IF)
sta.active(True)
sta.connect('HumidityServer', 'password#123')
while not sta.active():
pass
print('Connection successful')
print(sta.ifconfig())
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.connect(('192.168.45.1', 9000))
while True:
str_to_send = "Hello ESP8266: " + str(count)
s.sendto(str_to_send, ('192.168.45.1', 9000))
request = s.recv(1024)
print('Content = %s' % str(request))
count = count + 1
time.sleep(5)
if __name__ == "__main__":
main()
Related
I have an issue with running part of a code to be more specific defined as new thread CoreTask().
I have no idea why I cannot turn on/off built-in LED. The rest of the code looks to be working as expected (WIFI integration and 'httpd service' work fine).
I use Raspberry Pi Pico W with latest MicroPython loaded.
Please advice... Thanks!
import machine
import _thread
import network
import socket
import utime
from machine import Pin
led = machine.Pin('LED', machine.Pin.OUT)
ssid = 'someSSID'
password = 'somePASSWORD'
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
wlan.connect(ssid, password)
html = """<!DOCTYPE html>
<html>
<body>
<div id="humidity">100</div>
<div id="temperature">21</div>
</body>
</html>
"""
sLock = _thread.allocate_lock()
def CoreTask():
while True:
sLock.acquire()
print('LED...')
led.on()
utime.sleep(1)
led.off()
utime.sleep(1)
sLock.release()
_thread.start_new_thread(CoreTask, ())
while True:
sLock.acquire()
# Wait for connect or fail
max_wait = 10
while max_wait > 0:
if wlan.status() < 0 or wlan.status() >= 3:
break
max_wait -= 1
print('waiting for connection...')
utime.sleep(1)
# Handle connection error
if wlan.status() != 3:
raise RuntimeError('network connection failed')
else:
print('connected')
status = wlan.ifconfig()
print( 'ip = ' + status[0] )
# Open socket
addr = socket.getaddrinfo('0.0.0.0', 80)[0][-1]
s = socket.socket()
s.bind(addr)
s.listen(1)
print('listening on', addr)
# Listen for connections
while True:
try:
cl, addr = s.accept()
print('client connected from', addr)
request = cl.recv(1024)
print(request)
request = str(request)
response = html
cl.send('HTTP/1.0 200 OK\r\nContent-type: text/html\r\n\r\n')
cl.send(response)
cl.close()
except OSError as e:
cl.close()
print('connection closed')
sLock.release()
I'm also keen to know a solution, so far the best try I have got the onboard led working in seperate thread is the following simple code, every other more complicated try was failed.
I have only tested this with onboard LED, so if anyone may try if threading works on real GPIO? If it does, I think this is not an issue as most of time we send out "status blinks" on other LED in project not the onboard one.
import machine
import _thread
import time
def led():
led = machine.Pin('LED', machine.Pin.OUT)
while True:
led.on()
time.sleep(.5)
led.off()
time.sleep(.5)
def pnt():
i=0
while True:
i += 1
print(f"\rThis is the {i} cycle......", sep="", end="")
time.sleep(1)
if __name__ == "__main__":
th1 = _thread.start_new_thread(pnt, ())
#th2 = _thread.start_new_thread(led, ()) This line did not work
led()
I think someone said in a video that the threading is still in experiment and has problems on pico w, and they are working on it.
I also could not workout how to achieve same result with uasycncio, it looks like calling the LED to blink is not about programming but real physical movement, so cannot be "await". Can anyone show ma a correct way?
It's is such an important function to waiting for program (connection loop) while sending "status blinks"
i've made a local server using flask and mongoDB which works great on windows, but when i moved my code to the raspberry pi, i've got an error which i couldn't figure out why it occurs.
the code im using:
1) for the flask server
from flask import Flask
from flask import jsonify
from flask import request
import pymongo
import time
import datetime
import json
app = Flask(__name__)
client = pymongo.MongoClient("localhost", 27017)
db = client['mqtt-db']
obs_collection = db['mqtt-collection']
#app.route("/obs")
def obs():
data_str = request.args.get("data")
print data_str
data = json.loads(data_str)
print data
data["date"] = datetime.datetime.now()
obs_collection.save(data)
return "success"
#app.route("/get_obs")
def get_obs():
res = []
for row in obs_collection.find():
del row['_id']
res.append(row)
return jsonify(res)
#app.route("/delete_all")
def delete_all():
res = obs_collection.delete_many({})
return jsonify({"deleted": res.deleted_count})
if __name__ == "__main__":
app.run(host="0.0.0.0", debug=True)
2) script for inserting messages into db , using mqtt protocol:
import paho.mqtt.client as mqtt
import pymongo
import json
import datetime
topic = "sensor"
host = "10.0.0.6"
client = pymongo.MongoClient("localhost", 27017)
db = client['mqtt-db']
mqtt_collection = db['mqtt-collection']
# The callback for when the client receives a CONNACK response from the server.
def on_connect(client, userdata, flags, rc):
print("Connected with result code "+str(rc))
# Subscribing in on_connect() means that if we lose the connection and
# reconnect then subscriptions will be renewed.
client.subscribe(topic)
# The callback for when a PUBLISH message is received from the server.
def on_message(client, userdata, msg):
data_str = str(msg.payload)
data = json.loads(data_str)
print data_str
print data
data["date"] = datetime.datetime.now()
mqtt_collection.save(data)
print(msg.topic+" "+str(msg.payload))
client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message
client.connect(host, 1883, 60)
# Blocking call that processes network traffic, dispatches callbacks and
# handles reconnecting.
# Other loop*() functions are available that give a threaded interface and a
# manual interface.
client.loop_forever()
the error occurs when i try to retrieve data from the server using "get_obs" function.
the error is: "Value Error: dictionary update sequence element #0 has length 4; 2 is required"
appreciate your help.
as #davidism suggested, the solution was to update to the latest version of Flask
I've been working on a client for this chat server but I am running into a bit of a challenge. The server uses Python's 3.4RC1 asyncio module.
Behavior:
My client connects. My second client connects. Either can send messages to the server BUT, the server is not broadcasting them as it should in a normal public chat room.
User1: Hello. Presses Enter.
User2 does not see it.
User2: Anyone there? Presses Enter.
User2 sees User1: Hello. and User2: Anyone there?
Just... strange. Not sure what I'm missing.
Here are the files. Give it a try.
Server:
from socket import socket, SO_REUSEADDR, SOL_SOCKET
from asyncio import Task, coroutine, get_event_loop
class Peer(object):
def __init__(self, server, sock, name):
self.loop = server.loop
self.name = name
self._sock = sock
self._server = server
Task(self._peer_handler())
def send(self, data):
return self.loop.sock_send(self._sock, data.encode('utf-8'))
#coroutine
def _peer_handler(self):
try:
yield from self._peer_loop()
except IOError:
pass
finally:
self._server.remove(self)
#coroutine
def _peer_loop(self):
while True:
buf = yield from self.loop.sock_recv(self._sock, 1024)
if buf == b'':
break
self._server.broadcast('%s: %s' % (self.name, buf.decode('utf-8')))
class Server(object):
def __init__(self, loop, port):
self.loop = loop
self._serv_sock = socket()
self._serv_sock.setblocking(0)
self._serv_sock.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
self._serv_sock.bind(('',port))
self._serv_sock.listen(5)
self._peers = []
Task(self._server())
def remove(self, peer):
self._peers.remove(peer)
self.broadcast('Peer %s quit!' % (peer.name,))
def broadcast(self, message):
for peer in self._peers:
peer.send(message)
#coroutine
def _server(self):
while True:
peer_sock, peer_name = yield from self.loop.sock_accept(self._serv_sock)
peer_sock.setblocking(0)
peer = Peer(self, peer_sock, peer_name)
self._peers.append(peer)
self.broadcast('Peer %s connected!' % (peer.name,))
def main():
loop = get_event_loop()
Server(loop, 1234)
loop.run_forever()
if __name__ == '__main__':
main()
Client:
# import socket
from socket import *
# form socket import socket, bind, listen, recv, send
HOST = 'localhost' #localhost / 192.168.1.1
# LAN - 192.168.1.1
PORT = 1234
s = socket(AF_INET, SOCK_STREAM)# 98% of all socket programming will use AF_INET and SOCK_STREAM
s.connect((HOST, PORT))
while True:
message = input("Your Message: ")
encoded_msg = message.encode('utf-8')
s.send(encoded_msg)
print('Awaiting Reply..')
reply = s.recv(1024)
decoded_reply = reply.decode('utf-8')
decoded_reply = repr(decoded_reply)
print('Received ', decoded_reply)
s.close()
Here's the non threaded server code I wrote. works great but ONLY between 2 people. How could this code be updated to broadcast every message received to all clients connected?
# import socket
from socket import *
# form socket import socket, bind, listen, recv, send
HOST = 'localhost' #localhost / 192.168.1.1
# LAN - 192.168.1.1
PORT = 1234
s = socket(AF_INET, SOCK_STREAM) # 98% of all socket programming will use AF_INET and SOCK_STREAM
s.bind((HOST, PORT))
s.listen(5) # how many connections it can receive at one time
conn, addr = s.accept() # accept the connection
print('Connected by', addr) # print the address of the person connected
while True:
data = conn.recv(1024)
decoded_data = data.decode('utf-8')
data = repr(decoded_data)
print('Received ', decoded_data)
reply = input("Reply: ")
encoded_reply = reply.encode('utf-8')
conn.sendall(encoded_reply)
print('Server Started')
conn.close()
Okay, let’s think about what your client does. You ask for a message to send, blocking for user input. Then you send that message and receive whatever there is at the server. Afterwards, you block again, waiting for another message.
So when client A sends a text, client B is likely blocking for user input. As such, B won’t actually check if the server sent anything. It will only display what’s there after you have sent something.
Obviously, in a chat, you don’t want to block on user input. You want to continue receiving new messages from the server even if the user isn’t sending messages. So you need to separate those, and run both asynchronously.
I haven’t really done much with asyncio yet, so I don’t really know if this can be nicely done with it, but you essentially just need to put the reading and sending into two separate concurrent tasks, e.g. using threads or concurrent.futures.
A quick example of what you could do, using threading:
from socket import *
from threading import Thread
HOST = 'localhost'
PORT = 1234
s = socket(AF_INET, SOCK_STREAM)
s.connect((HOST, PORT))
def keepReading ():
try:
while True:
reply = s.recv(1024).decode()
print('Received ', reply)
except ConnectionAbortedError:
pass
t = Thread(target=keepReading)
t.start()
try:
while True:
message = input('')
s.send(message.encode())
except EOFError:
pass
finally:
s.close()
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()
I got multiple processes listening on the same port subscribed to a multicast address. Packets to this address reach every process. However, when I contact them via unicast, only the newest process gets the message. Where is this behavior documented? How can I change it?
Demo program (Python):
import socket,os,struct,sys
def server():
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind(('', 4242))
mreq = '\xef\x01\x02\x03' + struct.pack('=I', socket.INADDR_ANY)
sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
while True:
d = sock.recvfrom(1024)
print('[s' + str(os.getpid()) + '] ' + repr(d))
def client():
caddr = '239.1.2.3'
caddr = '127.0.0.1' # Uncomment this and all servers print
csock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
csock.sendto('data from ' + str(os.getpid()), 0, (caddr, 4242))
def main():
if sys.argv[1] == 's':
server()
else:
client()
if __name__ == '__main__':
main()
The MSDN states that the behaviour where multiple sockets are listening to the same port for unicast messages is undefined and that there's no way to know which one will receive the data. I tested a similar setup using C++ and winsock2.2 and had similar results as when I ran your program under python (namely the process-blocking effect).
Here's the MSDN article