CircuitPython Static IP WIZnet TCP Server & Client

code.py

import time
import traceback
import board
import digitalio
import adafruit_connection_manager
from adafruit_wiznet5k.adafruit_wiznet5k import WIZNET5K

time.sleep(3)  # wait for serial

# WIZnet W5500-EVB-Pico
spi = board.SPI()
cs = digitalio.DigitalInOut(board.GP17)
rst = digitalio.DigitalInOut(board.GP20)
radio = WIZNET5K(spi, cs, reset=rst, mac='de:ad:be:ef:fe:dd', is_dhcp=False, debug=False)
ipv4_address = radio.pretty_ip(radio.ip_address)
pool = adafruit_connection_manager.get_radio_socketpool(radio)

ip_address: str = "172.16.1.5"
subnet_mask: str = "255.255.255.0"
gateway_address: str = "10.0.0.1"  # does not exist
dns_server: str = "10.0.0.1"  # does not exist
radio.ifconfig = tuple(pool.inet_aton(num) for num in (ip_address, subnet_mask, gateway_address, dns_server))

HOST = ""
PORT = 5000
TIMEOUT = None
MAXBUF = 256

print("Create TCP Server Socket")
with pool.socket(pool.AF_INET, pool.SOCK_STREAM) as s:
    s.settimeout(TIMEOUT)

    s.bind((HOST, PORT))
    s.listen()
    print(f"Listening on {HOST}, {PORT}")

    buf = bytearray(MAXBUF)
    while True:
        print("Accepting connections")
        try:
            conn, addr = s.accept()
            conn.settimeout(TIMEOUT)
            print("Accepted from", addr)

            size = conn.recv_into(buf, MAXBUF)
            print("Received", buf[:size], size, "bytes")

            conn.send(buf[:size])
            print("Sent", buf[:size], size, "bytes")

            conn.close()
        except Exception as ex:
            traceback.print_exception(ex, ex, ex.__traceback__)

Server output:

code.py output:
Create TCP Server Socket
Listening on , 5000
Accepting connections
Accepted from ('0.0.0.0', 0)
Received bytearray(b'Hello, world') 12 bytes
Sent bytearray(b'Hello, world') 12 bytes
Accepting connections
Accepted from ('0.0.0.0', 0)
Received bytearray(b'Hello, world') 12 bytes
Sent bytearray(b'Hello, world') 12 bytes
Accepting connections
Accepted from ('172.16.1.1', 60413)
Received bytearray(b'Hello, world') 12 bytes
Sent bytearray(b'Hello, world') 12 bytes
Accepting connections
Accepted from ('172.16.1.1', 60414)
Received bytearray(b'Hello, world') 12 bytes
Sent bytearray(b'Hello, world') 12 bytes
Accepting connections

Client output:

Create TCP Client Socket
Connecting
Sent 12 bytes to 172.16.1.5:5000
Received b'Hello, world'
Connecting
Sent 12 bytes to 172.16.1.5:5000
Traceback (most recent call last):
  File "/Users/g/Desktop/tcp_client.py", line 25, in <module>
    buf = s.recv(MAXBUF)
socket.timeout: timed out
Connecting
Sent 12 bytes to 172.16.1.5:5000
Received b'Hello, world'
Connecting
Sent 12 bytes to 172.16.1.5:5000
Received b'Hello, world'
Connecting