This is a wrap-up article for interfacing hardware with 8051 microcontroller. It's a combo deal for starters because this time, I have interfaced switches, LEDs, seven-segment-display and keypad all at the same time. I have already talked about them, individually, in my previous articles but for better understanding I think it's important to know how they work together. It will also give you some idea about dividing your code into segments and pieces which ultimately polishes your code writing skills.