OSError: Network card not available

[misterlisty]

OSError: Network card not available What does this mean?

[Xykon]

The error is thrown when creating a socket but the esp32 cannot find a network card available to handle the request.

The error is thrown in modnetwork.c which is called by modsocket.c

[soren]

@xykon i'm getting this error for no apparent reason... even though i'm doing a hard reset.
is there a dev who knows what's happening?

[jmarcelino]

@soren
Can you post your code? or at least the network initialisation / sockets part.

Without more details it's impossible to help since you could be trying to initialise WiFi, LoRa, Sigfox...

[soren]

@jmarcelino Yes of course. Strange thing is, after unplugging the power completely (hard reset was not enough), problem stopped for now. Anyway, if there's something fishy, this is my boot:

import machine
import gc
from machine import UART
from network import WLAN
import pycom
import os
uart = UART(0, 115200)
os.dupterm(uart)
print('starting up...')
print(gc.mem_free())
gc.enable()
uart = UART(0, 115200)
os.dupterm(uart)
pycom.heartbeat(False)
pycom.rgbled(0x7f0000) # red

wlan = WLAN()
if machine.reset_cause() != machine.SOFT_RESET:
    print('setting wlan config...')
    wlan.init(mode=WLAN.STA)
    wlan.ifconfig(config=('10.42.0.14', '255.255.255.0', '10.42.0.1', '8.8.8.8'))

if not wlan.isconnected():
    print('looking for network...')
    wlan.connect('cooppifi', auth=(WLAN.WPA2, 'PasswordRemoved'), timeout=5000)
    while not wlan.isconnected():
        machine.idle()
print('connected to wifi!')
print(gc.mem_free())

and this is my main. the issue happens where i send to the socket:

from network import Bluetooth
import socket
#from network import socket
import pycom
import gc
import time
import machine
import binascii
from machine import Timer
pycom.heartbeat(False)
pycom.rgbled(0x000000) # turn off led
gc.enable()
lopyID = 4 # set this unique to each lopy
print('started! lopy id: ', lopyID)
print("a")
gc.collect()
print(gc.mem_free())
bluetooth = Bluetooth()
bluetooth.stop_scan()
time.sleep(1)
bluetooth.start_scan(-1)
adv = None # bluetooth advertisementa

time.sleep(1)
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
pycom.rgbled(0x007f00)

#print(gc.mem_free())
def sendToSocket(beaconID, rssi):
    print(gc.mem_free())
    RSSIpositive = rssi * -1
    string = str(lopyID) + "," + str(beaconID) + "," + str(RSSIpositive) + ","
    data = bytearray(string)
    addr = socket.getaddrinfo('10.42.0.1', 7007)[0][-1]
    s.sendto(data, addr)

# new mac adresses:
#C7:C3:83:EE:AA:A4
#FB:6F:11:25:79:9B
#F7:F0:BB:A6:ED:F7
#C3:C7:E7:73:7C:3F

while True:

    gc.collect()
    pycom.rgbled(0x007f00)
    advList = bluetooth.get_advertisements()
    for adv in advList:
        macRaw = adv[0] # binary mac address
        macReal = binascii.hexlify(macRaw) # convert to hexadecimal
        if macReal == b'fb6f1125799b': # old: b'f3bc0b6feb4c':
            print('beacon A rssi: ', adv[3]) # adv[3] is rssi
            sendToSocket(beaconID = 1, rssi = adv[3])
        elif macReal == b'f7f0bba6edf7': # old: b'edbed48d0b87':
            print('beacon B rssi: ', adv[3])
            sendToSocket(beaconID = 2, rssi = adv[3])
        elif macReal == b'c7c383eeaaa4': # <-- old
            print('beacon C rssi: ', adv[3])
            sendToSocket(beaconID = 3, rssi = adv[3])
        elif macReal == b'c3c7e7737c3f': # old: b'cd87e6a38dc2':
            print('beacon D rssi: ', adv[3])
            sendToSocket(beaconID = 4, rssi = adv[3]) # adv[3]
        gc.collect()
s.close()

[livius]

@soren
two things but i do not suppose that are releated to the issue:
you initialize twice UART and do dupterm

uart = UART(0, 115200)
os.dupterm(uart)
print('starting up...')
print(gc.mem_free())
gc.enable()
uart = UART(0, 115200)
os.dupterm(uart)

all above initialization can be ommited because dupterm is done in frozen _boot.py

second, you have enabled automatic garbage collecion gc.enable()
but then you use it manually gc.collect() - of course you can do this but is this intentional?

[soren]

@livius Ah shoot, I thought I was enabling manual garbage collectin with gc.enable(). And the UART duplication is obviously a mistake. Thanks for pointing those out !