II. Schematic

Wire the circuit as shown by the schematic below. It may be useful to used the 8051 pinout. Make sure the LED is connected correctly or it will not blink when you run your program. Below is another schematic which shows how the LED corresponds to it's symbol.

Schematic for Tutorial



LED schematic

III. Apparatus Required

1. LED (1)
2. 330k resistor (1)
3. 5V power supply
4. Phillips PDS51 "CE" Development System

IV. Program

   /* main.c */

   #pragma SMALL DB OE
   #include <reg51.h>
   
   sbit light = P2^0;
   
   /* Delay Function */
   void delay(void){
      int i, j;
   
      for(i=0; i<1000; i++){
         for(j=0; j<100; j++){
            i=i+0;
         }
      }
   }
   
   void main(void){
      while(1){
         light=0;   /* turns light on */
         delay();   /* without the delay function the light
                       would blink to quickly for us to see */
         light=1;   /* turns light off */
         delay();
      }
   }

V. Procedure

Creating The Program File

1. Create a folder in the C directory called tutorial
2. Type in the following program into any text editor (i.e. notepad, wordpad, ...) and save to C:\tutorial