`OSError: Network card not available` on first boot

[amotl]

Hi there,

@didilamken reported at ¹:

I wanted to install the latest version of FiPy-master from 10.05.2021, but there are errors right at the first boot:

Traceback (most recent call last):
  File "<stdin>", line 17, in <module>
  File "webserver.py", line 142, in <module>
  File "/flash/lib/microDNSSrv.py", line 19, in Create
  File "/flash/lib/microDNSSrv.py", line 161, in Start
OSError: Network card not available

With kind regards,
Andreas.

Footnotes

1. https://community.hiveeyes.org/t/vorbereitungen-fur-bob-workshop-in-hannover-im-marz-2023/4745/5 ↩

[amotl]

I discovered a few other network-related issues here. Maybe those are related, or GH-33 fixes the problem already?

• FiPy öffnet keinen AP  #14
• FiPy hat Probleme sich mit WLAN zu connecten #16
• Fix Bug Wifi on Boot #33

[amotl]

At ¹, I've recommended to improve the code base a bit.

At this spot, Python code is defined at the module level within the webserver.py file, so it is already invoked when the modules are being loaded. This should be avoided.

FiPy/webserver.py

Lines 139 to 142 in 01b403b

	print("in webserver.py")
	mws = MicroWebSrv()
	mws.SetNotFoundPageUrl("http://hiverize.wifi")
	MicroDNSSrv.Create({ '*' : '192.168.4.1' })

The code should be encapsulated into a function that is only called when it makes sense, i.e. when the "network is there" ². Perhaps the enable_ap() function could be used?

FiPy/main.py

Lines 293 to 306 in 01b403b

	# enable ap
	def enable_ap(pin=None):
	global _wm, loop_run, _wlan, wdt, button_ap
	# if in button mode, make sure we don't enter this function again
	if _config.get_value('general', 'general', 'button_ap_enabled'):
	button_ap.callback(Pin.IRQ_FALLING, handler=ap_already_enabled)
	print("Called. Pin {}.".format(pin))
	wdt.init(timeout=10*60*1000)
	if not _wlan.mode() == network.WLAN.AP:
	loop_run = False
	_wm.enable_ap()
	if not webserver.mws.IsStarted():
	webserver.mws.Start(threaded=True)
	print("Webserver started!")

Footnotes

1. https://community.hiveeyes.org/t/vorbereitungen-fur-bob-workshop-in-hannover-im-marz-2023/4745/27 ↩

2. A module can contain executable statements as well as function definitions. These statements are intended to initialize the module. They are executed only the first time the module name is encountered in an import statement. -- https://docs.python.org/3/tutorial/modules.html#more-on-modules ↩