Chapter 3 - Light Projects

Abstract

Publisher Summary This chapter highlights simple light projects using the basic 89C2051 microcontroller circuit. It also reviews projects ranging from very simple LED display projects to complex projects incorporating alphanumeric displays. Each project consists of information such as function, circuit diagram, program description, program listing, and components required. LED binary counter project counts up in binary and displays the result on eight LEDs connected to port 1 of the microcontroller. The circuit is extremely simple consisting of the basic 89C2051-based microcontroller and eight LEDs connected to port 1 of the microcontroller. Each microcontroller output pin can sink a maximum of 80 mA and source up to 20 mA. According to the program description of this project, the program is required to increment a value and then output to port 1 of the microcontroller. As the microcontroller operates at a very high speed, it is necessary to insert a delay in the program, so that the LED outputs can be seen visually. In the program listing the variable LED is initialized to 1 and is used as the counter. Variable P1 is defined in include file “AT892051.h” and this is a reserved name for port 1 of the microcontroller. In addition to the components required by the basic microcontroller circuit, R2 and D are required for the project.