I wish i could help you with your quest for info, unfortunately tutorials on the ESP are several but hardly any are good and i struggled as much as you did, mind you not on the forum.. about the server.on("/",[] () { }); it is a 'declaration of callback function' .. i think.. i got all the stuff from Tut's as well and once i got a handle on what server.on("/",functionName); was doing i learned to work with it. One of the things about the ESP is that there are so many ways to approach the issue (via AT commands fi) how to use HTML etc I do recommend a book on HTML and you have a lot of the basics of the ESP already. I found out about the yield() via googling some reset issues i was having and that fixed my code !! I had already passed a hurdle before when i could work out a reset occurring until i came to the conclusion that an accidental division by 0 on an ESP causes a reset, it probably should on an Arduino as well but it doesn't. That the EEPROM needs the .begin() .commit() and .end() functions called to function on an ESP and sorts, good luck you managed congrats !