Connect the 8051 microcontroller to the 8255 Peripheral Interface Adapter. Connect the 4x4 keypad and 7-segment display to the 8255 interface as per the circuit diagram provided in the project ...

Then we connected Port-2 pins of 89c52 microcontroller to our 16×2 lcd data pins(D0-D7). We connected: enable pin of lcd with Port-3 to the third pin. RS(register select) pin of lcd with Port-3 pin 5.