This system converts a decimal number between $0$ and $255$ to hexadecimal, and shows the result on an LCD. User input must be through a $44$ keypad.

$28.$ Decimal to hexadecimal converter

This system converts a decimal number between $0$ and $255$ to hexadecimal, and shows the result on the seven segment display. User input must be through a $44$ keypad.

$29.$ Dot Matrix Display Controller

In this project, a LED matrix or $168)$ shows three marquee texts. The text which will be shown on the display, must selected$/$changed with a push$-$button or switch.

$30.$ ON$-$OFF temperature control

This system is an on$-$off type temperature control for a room. The desired temperature is entered using a $44$ keypad. The actual temperature is measured in every $10$ seconds and compared with the entered value. If the desired value is higher than the measured one, a green LED is turned on; otherwise a blue LED.

$31.$ Digital Counter

Design a counter system employing a $7$segment display $($SSD$)$ and three switches, one for increasing, the second one for decreasing and the last one for resetting. the number shown on the display. The display must show up to at least $3$ digits.