Startup code for the Arduino UNO R4 boards (RA4M1 processor) to change from the internal HOCO clock to an external XTAL for the main processor functions. The USB interface remains on the HOCO clock.

this project will help users to automate home electrical switches like for fan and lights using arduiono uno USE ARDUINO UNO TO DEVELOP A FILE also change the id ans password in ino file for wifi ...