Step 1.) The first step is to build the circuit. At this point you should be familiar with the parts used. You can either put these parts together using a breadboard or wirewrap. This design is intended for use with an Atmel 2051. Most microcontrollers (such as a normal 8051 or 8751) can not handle the current required to turn an LED on and off but the ATMEL part has this capability.

Vcc = 5V and Gnd = 0V

The basic process of compiling an assembly language program and loading it into the microcontroller was covered in the first microcontroller project.In this project the program is similar. Instead of just making an LED blink, we are using all of Port 1 on the 2051 to make an 8 bit counter. The program for this is ledproj2.asm. It is included on the CD that comes with the Microcontroller Beginner Kit. Once you have compiled the program, download it to the 2051. Make sure the power is off for the circuit you have built. Then move the microcontroller to the circuit.

Turn on the power to the circuit. The LEDs should all come on. Then they should start blinking on and off as the counter counts up from 0 to 255 (all on to all off).