Added webGUI, implemented communication API, save wifi credentials and general config to file

General info

• Added web GUI to folder: SW/Web-Configurator
• Added WifiManager for managing configuration of wifi state
• Added Base64 library by Arturo Guadalupi directly to the project, because importing library with library manager didn't work, see Base64Class.h
• changed ConfigManager.cpp in order to be able to load config from file - WIP

API

These are the implemented API commands:

• setWifi <SSID> <password>: sets the credentials to be used to connect with wifi
• tts <text>: plays the given text using text-to-speech
• toggleWiFi <on | any>: turn on wifi if agrument is on, otherwise turn off wifi
• rm <filename>: removes <filename>.mp3 from SD card (in order to remove cached version of TTS)
• wav <filename>: plays <filename>.wav from SD card
• mp3 <filename>: plays <filename>.mp3 from SD card
• vol <0..100)> sets sound volumne to given value
• restart or reboot: restarts the system
• refreshtokens: refreshes HomeConnect access tokens
• checktokens: check HomeConnect access tokens if they are valid
• time: prints current system time as timestamp
• logheap toggles printing current heap memory usage
• wifiinfo: returns currently used SSID
• setConfiguration <configJSON>: takes a JSON string representing the system configuration, saves it and reboots for using this configuration
• callAPIEncoded <cmdName> <arg1> <arg2>: possibility to call all other API commands with base64 encoded arguments. For instance callAPIEncoded setWifi bXlXaWZp bXlQYXNzd29yZA== will call setWifi myWifi myPassword internally.

Calling the API via callAPIEncoded is used for communication with the WebGUI in order to make it possible to send values including spaces, e.g. a wifi password.

WifiManager

Some information about the new behaviour of WifiManager:

• credentials are read from file WifiData.txt from SD card
• connecting to Wifi is tried 3 times or at maximum 60 seconds, afterwards device is used without Wifi (new credentials could be set via API)

Start WebGUI

Go to folder SW/Web-Configurator and run npm install and npm run serve, also see Readme.md

Important notes for further development

• the API call setConfiguration <configJSON> currently isn't working, because we ran into memory issues. Config files currently are about 15000 characters long and raising the limits for API arguments and adding big arrays to ConfigManager.cpp for holding such big arrays led to boot loops of the M5Stack. See this commit for fixing the reboot loop.
• communication from M5Stack -> WebGUI is not finished. The WebGUI receives everything sent from M5Stack over Serial, but there is no mechanism to detect what is a result to a prior API call.