SensESP v3 alpha

[mairas]

For those who are interested in ESP32 sensor device development, and SensESP in particular:

I have just pushed a new dev-3 branch to the SensESP repo, representing an alpha version of SensESP v3. The new branch represents several months worth of development, mainly focusing in a complete rewrite of the web config UI. The config UI, written in React typescript, provides (hopefully) a much more polished experience, with user-friendly UIs for WiFi, SK and system settings. It also supports a plugin system, allowing creating application-specific config pages. WiFiManager is no longer used. Instead, the same UI is used both for initial WiFi setup and other system configuration.

Other noteworthy changes:

• Implemented HTTP Digest Authentication for the config UI, meaning that the UI is now (optionally) protected by a username and a password
• Got rid of the Startable base class because it was really not required.
• Use ArduinoJson 7
• Squash a bunch of bugs

Most of the internal plumbing is backwards-compatible. Some addons may require small changes to compile. For example, ValueConsumer::set_input() has been renamed to ::set().

The new code has had very little testing so far. If you're interested, please have a go and report the results. You can update existing projects by editing platformio.ini and replacing the SensESP dependency in the lib_deps section with the following:

https://github.com/SignalK/SensESP.git#dev-3