Now it is time to modify uartecho. Your code will need to accomplish the following: $$ Use only one byte of RAM for the serial buffer $($ charinput; $).$ Use only one byte of RAM for the state $($ unsigned char state; $).$ Receive only one character at a time from the UART and it is not buffered. $$ Turn on an LED when a user types ON into the console. $$ Turn off the LED when a user types OFF into the console.