Question 1 (12 pts.): a. (4 pts.) Show the connection of the TX and RX pins of the ATmega128 to a DB-9 RS232 connector via the second set of line drivers of MAX233. b. (3 pts.) When is the UDRE flag bit raised or cleared? c. (1 pts.) Which of the following ADC sizes provides the best resolution? i. 8-bit ii. 10-bit iii. 12-bit iv. 16-bit v. They are all the same. d. (2 pts.) In the A/D of ATmega128, what happens to the converted analog data? How do we know that the ADC is ready to provide us the data? e. (1 pts.) A DC motor is moving a load. How do we keep the RPM constant? f. (1 pts.) What is the advantage of placing an optoisolator between the motor and the microcontroller