urequest could not request the server after short downtime

[mattm]

Hello,

i have a Arduino Nano RP2040 Connect and a simple program to read a reed contact. In a loop the current reed contact value should be send to a server. Actually the server is a simple docker container.

The Arduino can send the data to the server as long as it is reachable. So far so good.
If the server fails briefly (docker container is stopped) and is running again, no more requests from the Arduino reach it. What can be the reason?

Code: Select all

import machine, time, socket
from machine import Pin
from network import WLAN, STA_IF

reed_pin = Pin(17, Pin.IN, Pin.PULL_UP)
led_pin = Pin(6, Pin.OUT)

# AP info
SSID=''        # Network SSID
KEY=''  # Network key

PORT = 3001
HOST = "192.168.178.53"

def connect_wifi():
    # Init wlan module and connect to network
    print("Trying to connect. Note this may take a while...")
    
    wlan = WLAN(STA_IF)
    if not wlan.isconnected():
        print('connecting to network...')
        wlan.active(True)
        wlan.connect(SSID, KEY)
        while not wlan.isconnected():
            pass

    # We should have a valid IP now via DHCP
    print("Wi-Fi Connected ", wlan.ifconfig())

def send_request(value):

    # Get addr info via DNS
    addr = socket.getaddrinfo(HOST, PORT)[0][4]
    print(addr)
    
    # Create a new socket and connect to addr
    client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    client.connect(addr)

    # Set timeout
    client.settimeout(3.0)

    # Send HTTP request and recv response
    client.send(f"GET /?meterType=gas&meterId=1&value={value} HTTP/1.1\r\nHost: {HOST}\r\n\r\n")
    print(client.recv(1024))

    # Close socket
    client.close()

connect_wifi()

while True:
    print("Read: ", reed_pin.value())
    led_pin.value(reed_pin.value())
    
    if (reed_pin.value() == 0):
        send_request(0)
        time.sleep_ms(1000)
    else: 
        send_request(1)
        time.sleep_ms(1000)
        
    led_pin.value(1)
    time.sleep_ms(300)
    led_pin.value(0)
    time.sleep_ms(300)

The LED keeps blinking, so the loop keeps running.

[curt]

I would verify that the server is actually running (listening). If it was only down briefly, the restart could have failed trying to open the port because the port was in a TIME_WAIT state.

Curt

[karfas]

Shouldn't settimeout() get called before connect() ?
I wonder that connect() doesn't raise an exception when the connect (obviously) is not working.

See e.g. https://github.com/micropython/micropyt ... equests.py:

Code: Select all

    s = usocket.socket(ai[0], usocket.SOCK_STREAM, ai[2])

    if timeout is not None:
        # Note: settimeout is not supported on all platforms, will raise
        # an AttributeError if not available.
        s.settimeout(timeout)

    try:
        s.connect(ai[-1])