5
Click ‘Tools’ -> ‘Board:’ -> ‘Board Manager…’ to access this panel.
Scroll down to
‘ esp8266 by ESP8266 Community ’ and click “Install” button to install the ESP8266 library package.
Once installation completed, close and re-open Arduino IDE for ESP8266 library to take effect.
Setup ESP8266 Support
When you've restarted Arduino IDE, select
‘Generic ESP8266 Module’ from the ‘Tools’ -> ‘Board:’ dropdown menu.
Select 80 MHz as the CPU frequency (you can try 160 MHz overclock later)
