(PIC16F877A) 128x68 Graphic Display

Let us see the presentation first 

Schematic

Please refer the specific controller page for details for Microcontroller & Compiler

You can download the code from here

(P89v51RD2) 20x4 LCD

20x4 LCD is extended version of 16x2 LCD the only difference is their size & capacity to display
16x2 is 16 character x 2 lines &
20x4 is 16 character x 4 lines
Their interfacing is same. Please refer the bottom memory diagram for 20x4 in the slide which is same for 16x2

Please find controller specific details & compiler details on that specific page.
You can download code from here

(P89v51RD2) 7 Segment

Let us have the presentation first

Now we have 8 7-segment display.
How many microcontroller pins are required to interface it.
You might me thinking it would be 8x7=56. Microcontroller don't even have that many I/O.
So we would go ahead for multiplexing which would utilize just 16 I/O lines

Refer to schematic below

Now i have 2 codes for this that explain different cases when you work on it

Get the details
Microcontroller Platform: MCS 51
Microcontroller: NXP P89v51RD2
Compiler: Uvision Kiel
You can download code from
1) here
2) here

(P89v51RD2) Blink LED !!!!!

The best way to get started is to learn the I/O Ports. The simplest Peripheral to get started is LED. Here is the presentation for the LED blinking.

Problem Statement: Blink a LED
Microcontroller Platform: MCS-51
Microcontroller: NXP P89v51RD2
Compiler: Uvision Keil



To download code you can visit  here