Led Blinking

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  • Topic: PIC microcontroller, EPROM, Light-emitting diode
  • Pages : 8 (1904 words )
  • Download(s) : 138
  • Published : November 9, 2011
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1.1 Background of the Project

LED blinking project can be used as attraction. This project was done with PIC16877A. The LED will blinking on delay timer which make the LED look like running.

1.2 Problem Statement

The circuit need to off manually or need to cut the voltage to stop the blink. By using the magnetic switch the circuit can off by giving input to the PIC.

1.3 Objective

The objective of this project is to develop the LED blinking circuit together with the program.

1.4 Project Implementation



2.0 Background of Study
2.1 LED
A light-emitting diode (LED is a semiconductor light source. LEDs are used as indicator lamps in many devices, and are increasingly used for lighting. Introduced as a practical electronic component in 1962, early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet and infrared wavelengths, with very high brightness. When a light-emitting diode is forward biased (switched on), electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the colour of the light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor. An LED is often small in area ( and integrated optical components may be used to shape its radiation pattern. LEDs present many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved robustness, smaller size, faster switching, and greater durability and reliability. LEDs powerful enough for room lighting are relatively expensive and require more precise current and heat management than compact fluorescent lamp sources of comparable output. Light-emitting diodes are used in applications as diverse as replacements for aviation lighting, automotive lighting (particularly brake lamps, turn signals and indicators) as well as in traffic signals. The compact size, the possibility of narrow bandwidth, switching speed, and extreme reliability of LEDs has allowed new text and video displays and sensors to be developed, while their high switching rates are also useful in advanced communications technology. Infrared LEDs are also used in the remote control units of many commercial products including televisions, DVD players, and other domestic appliances.

Figure shows example of LED
2.1.2 PIC
PIC is a family of Harvard architecture microcontrollers made by Microchip Technology, derived from the PIC1640 originally developed by General Instrument's Microelectronics Division. The name PIC initially referred to "Peripheral Interface Controller". PICs are popular with both industrial developers and hobbyists alike due to their low cost, wide availability, large user base, extensive collection of application notes, availability of low cost or free development tools, and serial programming (and re-programming with flash memory) capability. The original PIC was built to be used with General Instruments' new 16-bit CPU, the CP1600. While generally a good CPU, the CP1600 had poor I/O performance, and the 8-bit PIC was developed in 1975 to improve performance of the overall system by offloading I/O tasks from the CPU. The PIC used simple microcode stored in ROM to perform its tasks, and although the term was not used at the time, it shares some common features with RISC designs. In 1985, General Instruments spun off their microelectronics division and the new ownership cancelled almost everything — which by this time was mostly out-of-date. The PIC, however, was upgraded with internal EPROM to produce a programmable channel controller and today a huge variety of PICs are available with various on-board peripherals and program memory from 256 words to 64k words and more (a "word" is one...
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