In theArduino uno keypad interfacing circuit, you can observe that I have only took two control pins. This give the flexibility of better understanding, the contrast bit and READ/WRITE are not often used so they
For the interfacing of the keypad with the microcontroller, it is good to connect the LCD as well; this way, we can observe specific changes when we press the key on the keypad. We will connect the Keypad 4×3 (which has 4 rows and 3 columns) to Port 3 of the 8051 microcontroller ...