$1.$ Write a C program for the Arduino Mega which will:Monitor incoming characters from the Megas UART, for A$,$ B$,$ C$,$ D$,$ E$,$ F$,$ G$,$ and Q$,$ usingthe serial functions you wrote in the UART lab $($U$0$Init$(),$ kbhit$(),$ getchar$(),$ andputchar$()).$Generate a square wave on Port B$\mathrm{.}6$ of the appropriate frequency depending on the keypressed, as indicated in the table below.Output logical $0$ when the program first starts, and after the UART receives a QcharacterFrequency TableNote Frequency HzA $440$B $494$C $523$D $587$E $659$F $698$G $784$NOTE: Generating the square wave will not take place in the main loop of the program,but instead in the overflow Interrupt Service Routine of Timer #$1.$Hint: Start with the code you wrote in the Timer Lab, and make two changes:Implement your own serial I$/$O routines U$0$Init$(),$ kbhit$(),$ getchar$(),$ and putchar$()$instead of the Arduino library serial functions to read the note to be played from theUART.Implement an ISR function for the Overflow Interrupt on Timer #$1($TIMER$1$ OVF$)$which will: