Automatic Humanoid Operated Door

Automatic Humanoid Operated Door Using 8051

Basic Introduction to 8051 Microcontroller:

AT80C51 is a most popular microcontroller, developed principally for bringing into play in embedded systems. These most modern microcontrollers need fewer amount of power to function in comparison to their forerunners. In 8051, two storage devices are available for both program and data of 64K by 8 sizes.

The 8051 microcontroller consists of 8 bit accumulator and 8 bit processing unit. It also consists of 8 bit register as majorly functioning blocks. It also has a number of other 8 bit and 16 bit registers. For internal functioning and processing microcontroller 8051 comes with integrated built-in RAM. This is prime memory and is employed for storing temporary data. It is unpredictable memory i.e. its data can get be lost when the power supply to the microcontroller switched OFF.

The 8051 microcontrollers are used in various fields starting from consumer electronics to large scale industrial applications. Some of the applications of microcontroller are:

·         Defense applications

·         Automobile

·         Mobile communication

·         Medical applications

·         Consumer electronics

·         Industrial applications

Microcontroller Based Projects

So, in these days the microcontrollers are found in every walk life.

In this article, we are explaining one of the application of 8051 microcontroller in automatic door opening system. Let’s see

Application of 8051 Microcontroller in Automatic Door Opening System:

Opening and closing of doors is always a tedious job, especially in places like shopping malls, hotels and theatres where a person is always required to open the door for visitors. So in this article we are going to introduce an automatic humanoid operated door using 8051 microcontroller. An automatic door opening system is achieved by sensing any approaching body by PIR sensor interfaced to programmed microcontroller of 8051.

The output of power supply which is 5v is connected to 40th pin of microcontroller and ground is connected to 20th pin of microcontroller.

Generally, human body emits infrared energy which is sensed by the PIR sensor from a considerable distance. The output from the PIR sensor i.e., passive infrared detector is amplified to a transistor BC547, the output of which at the collector is connected to pin 1 of the microcontroller. While any moving object is sensed by the PIR it develops logic high at its output which gets inverted by the transistor used to develop a logic low at pin 1 of microcontroller. The program is so written that it delivers appropriate input to the motor driver IC L293D as explained above, to run the motor in one direction, so as to enable a door open situation. As the door gets fully opened an interrupt signal is received from the motor door from an SPDT leaf switch to stop the motor by placing zero logic once the door reaches to extreme end to enable pin of L293D for disabling the motor. After few seconds the microcontroller sends reverse logic to the motor driver IC such that the motor rotates in the opposite direction representing closing of the door.