General-purpose microprocessors contain no RAM, no ROM and no I/O ports on the chip itself. Microprocessors contain processor, RAM, ROM, I/O ports, timer, ADC and other peripherals on one chip. In embedded system there are widely used microprocessors and Microprocessors. There are four major 8-bit Microprocessors. They are Motoroläs 6811, Intel¿s 8085, Zilog¿s Z8 and Microchip¿s PIC. Each of these Microprocessors has a unique instruction set and register set; therefore, they are not compatible with each other. Programs written for one will not run on the others. There are also 16-bit and 32-bit Microprocessors made by various chip makers. In this project we have chosen 8085 (AT89S51) for it¿s cost effective, availability of software development tools and widely available in market. Presently Micro-controller (MCU) is being widely used in almost every field of science and engineering. The knowledge of MCU, which was once the monopoly of Electrical and Electronic Engineers, has now a demand for the people of all science and engineering disciplines. It is also the requirement of ABET that engineering students must demonstrate a knowledge of data acquisition.