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Need help Setting up the Pico W up as an access point

gregaryb

I am in the process of setting up a wrapper class for setting the Pico up as either an access point or just connecting to an existing network.

Forget about 'BeginHTTP(self, bIsAccessPoint, strSSID, strPassword):' - I have not tested that function yet.

I am only working on ' BeginUDP(self, bIsAccessPoint, strSSID, strPassword, nPort):'

This begin function is being called like so:

BeginUDP(True, "AARONS_ROBOT", "PICO123456", 10002)

The function exits with no error message.

My message stating that the access point has been started and is listening on port 10002 is displayed.

The access point appears on my mobile phone.

But when I try and connect to it, the connection times out and fails.

Why?

=====================================================


import socket
import network

class CWiFi:

    strSSID = ""
    strPassword = ""
    WiFi = 0
    nPort = 0
    Socket = 0
    strIPAddr = ""
    strIPAddrRequest = ""
    nReceiveDataSize = 2048
    Socket = 0
    Client = 0
    
    # Function overloading not allowed in Python so the constructor does nothing useful
    def __init_():
        strSSID = ""
        
    # Common setup tasks
    def Begin(self, bIsAccessPoint, strSSID, strPassword):
        self.strSSID = strSSID
        self.strPassword = strPassword
        self.WiFi = network.WLAN(network.AP_IF) # Access point
        
        # Start Access Point
        if (bIsAccessPoint):
            self.WiFi.config(essid = strSSID, password = strPassword)
            self.WiFi.active(True)

            while self.WiFi.active == False:
                pass

            self.strIPAddr = str(self.WiFi.ifconfig()[0])
            print("Access point started with IP address '" + self.strIPAddr + "'")
        # Connect to existing network
        else:
            self.WiFi.active(True)
            self.WiFi.connect(strSSID, strPassword)
            while (self.WiFi.isconnected() == False):
                print('Waiting for connection...')
                sleep(1)
            self.strIPAddr = self.WiFi.ifconfig()[0]
            print("Connected to SSID: '" + strSSID + ", with IP address: '" + self.strIPAddr + "'")

    # Setup the AP for HTTP requests
    def BeginHTTP(self, bIsAccessPoint, strSSID, strPassword):
        self.Begin(bIsAccessPoint, strSSID, strPassword)
        self.nPort = 80
        self.Socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)   #creating socket object
        self.Socket.bind((self.strIPAddr, nPort))
        self.Socket.listen(1)
        print("Waiting for request on port '" + str(self.nPort) + "'...")
        
    # Setup the AP for UDP messages
    def BeginUDP(self, bIsAccessPoint, strSSID, strPassword, nPort):
        self.Begin(bIsAccessPoint, strSSID, strPassword)
        self.nPort = nPort
        self.Socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.Socket.bind((self.strIPAddr, self.nPort))
        print("Waiting for request on port '" + str(self.nPort) + "'...")

  • 0

    Hi,

    Regarding "The access point appears on my mobile phone. But when I try and connect to it, the connection times out and fails." are you referring to a WiFi connection failure, or some application timeout/failure to send UDP?

    If it's the former, then you could try the very stripped down code here: https://www.recantha.co.uk/blog/?p=21398 (under the heading "Initial access point" and if that doesn't work, it could be a hardware or power issue, or perhaps something to do with your setup (a photo may be needed) or old micropython firmware possibly.

    If it's the latter, is there some code missing from the end? There should be a self.Socket.udp_recv or something. 

    I have not tried it myself, but an example here contains that: https://forums.raspberrypi.com/viewtopic.php?t=340208

    There could even be an issue with the mobile app with UDP perhaps, since there are often slight changes in different releases of app and mobile OS. If there's any doubt, then it could be worthwhile attempting UDP client from a PC instead (and make sure it's allowed in the firewall configuration). 

  • 0 in reply to shabaz

    I don't get as far as Socket.udp_recv mate. The login fails before that. My phone asks me to change the password.

  • 0

    I gave it a quick shot, and this functioned for me, it is simpler code (no class and no switching between existing WLAN and WAP modes, it is WAP mode only) just to see if it works:

    import socket
import network

ssid = "PicoW"
password = "b0bb0bb0b"
sock = None

ap = network.WLAN(network.AP_IF)
ap.config(essid=ssid, password=password) 
ap.active(True)

while ap.active == False:
  pass

print("Access point active")
print(ap.ifconfig())

def udp_server_setup(portnum):
    global sock
    if not ap.active:
        print("error, AP is not active yet")
    sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    server_ip = socket.getaddrinfo("0.0.0.0", portnum, socket.AF_INET, socket.SOCK_DGRAM)
    sock.bind(server_ip[0][4])
    print(f"Waiting for request on {server_ip}:{portnum}")
    while True:
        pkt = sock.recv(4)
        if len(pkt)<1:
            print(f"packet length is {len(pkt)}")
        else:
            print(f"packet is {pkt}")



udp_server_setup(1250)

    With the above code (I used the latest micropython linked to from the Pi page)

    I see this:

    MicroPython v1.19.1 on 2022-10-11; Raspberry Pi Pico W with RP2040
    Type "help()" for more information.
    >>> import pico_wap_test
    Access point active
    ('192.168.4.1', '255.255.255.0', '192.168.4.1', '0.0.0.0')
    Waiting for request on [(2, 1, 0, '', ('0.0.0.0', 1250))]:1250
    packet is b'Abcd'

    I sent a UDP packet from my Windows laptop, because I don't have an app on my mobile, the debug above shows the packet contained "Abcd".

    The mobile (running Android) did connect to the Pico's SSID, even though I didn't test the UDP packet.

    image