WiFi connection logic improvements

[mairas]

SensESP WiFi connection logic was a bit fragile and unnecessarily complex. Different connecting code was used depending on whether the WiFI AP was hard-coded or configured via WiFi Manager, and also reconnecting in case of lost WiFi was unreliable. This PR attempts to address those issues.

Major changes:

• WiFi Manager configuration portal is only enabled if no previous configuration has been saved. Once SSID and password have been entered and verified to work, they will be used ever after (or at least until the device is reset).
• If the WiFi AP is not available or the connection is lost, the device will keep attempting to reconnect until a connection has been established. WiFi Manager never gets launched, and these reconnection attempts are non-blocking (so the device is still operating normally, albeit without network).
• WiFi Manager operates still in a blocking fashion, but since it's never launched during normal operation, this is less harmful than before.

[ba58smith]

If you change the actual SSID and/or password of your wifi network, do you just reset the SensESP device, so that WiFiManager will launch?

[mairas]

If you change the actual SSID and/or password of your wifi network, do you just reset the SensESP device, so that WiFiManager will launch?

Yes. You'll save yourself some hassle if you remember to perform the reset before changing the SSID. Otherwise you might have to create e.g. a mobile phone hotspot with the correct SSID and password to access the device.

It might be possible to revisit the topic in the future and make the WiFiManager setup properly non-blocking, or make it run in a separate ESP32 task, but both are a bit more substantial changes than I was prepared to tackle at this point. This way, all network configuration could go through WiFiManager (even in the case of hard-coded values), and the operation would not prevent other code from running while the configuration portal is active.

Some future improvements here would be:

• implement a button configuration interface (long press resets the device). I've done that for another project and could try to import that to SensESP at some point.
• Have a web UI button to only reset the network settings: if the device has e.g. complex calibration curves, it'd be nice to save them. Again, for the future.

[ckcrs]

Thanks a lot... Just testing and curios about "device is still operating normally, albeit without network" part. Should I also expect to see normal data output from esp32 at my usb serial connection? Sancan PS: I can see below on by usb serial, till it reconnects to my restarting RPi, then data reporting starts: "(wifi_station_disconnected)(C1) Disconnected from wifi. (connect)(C0) WiFi is disconnected. SignalK client connection will connect when WiFi is connected.

Edit: I guess not, not related with freetos. :)

[mairas]

Thanks a lot... Just testing and curios about "device is still operating normally, albeit without network" part. Should I also expect to see normal data output from esp32 at my usb serial connection?

If you're referring to the Signal K deltas that are printed out when the data is transmitted to the SK server, then no, that data is not printed out as long as the data isn't being transmitted.