import network
import time
import socket
import struct
import sys

ssid = None
password = None

MCAST_GROUP = '239.3.3.3'
MCAST_PORT = 50007

def inet_aton(ip_str):
    return bytes(map(int, ip_str.split('.')))

wlan = network.WLAN(network.STA_IF)
wlan.active(True)
if ssid:
    wlan.connect(ssid, password)
    while not wlan.isconnected():
        time.sleep(0.25)

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

mreq = struct.pack("4sL", inet_aton(MCAST_GROUP), 0) 
print ('mreq:', mreq)

try:
    sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
    print("success")
except Exception as e:
    sys.print_exception(e)
    sys.exit()

while True:
    try:
        print('recv:', sock.recv(1024))
    except Exception as e:
        sys.print_exception(e)
        sys.exit()