A microcontroller is a single-chip computer. Before the invention of the microcontrollers most intelligent systems were designed using microprocessors. A microprocessor is the processing element of a computer, consisting of an Arithmetic and Logic Unit (ALU) and the Control Unit (CU). A microprocessor on its own is useless and it has to be supported by a large number of peripheral chips, such as memory, input-output, timer, interrupt logic and so on. Currently there are many microcontroller chips manufactured by various companies. This book is based on using the highly popular PIC16F887 type...

This book is about designing a microcontroller based alcohol detector device, also known as a breathalyzer device. The designed device basically consists of an alcohol sensor chip, a microcontroller development system, a text based LCD display, 3 coloured LEDs, and a speech processor module. The user blows onto the alcohol sensor through a small plastic tube. The alcohol sensor generates a voltage proportional to the measured alcohol level. This analog voltage is fed to the A/D converter input of a PIC16F887 microcontroller. The microcontroller processes the signal and calculates the actual...