A numerical keypad and a common cathode 7-segment display with the following arrangement are to be interfaced to an 8051 microcontroller (Figure Q4b). i. Write a subroutine to continuously scan the keypad and return the position of the column and row of the key pressed into R1 and R2 respectively. [8 marks] ii. Given the row information is stored in R1, while the column information is stored in R2. Write a subroutine to display the key pressed character ('.', '-', '0', ' 1 '...' 9 ') to the 7 -segment display. [7 marks]