Motion detection movable Robot with AT89C51

  The motion dependent applications are becoming  more popular in the present days for example  a door can open when there is a human movement in the sensor region. Likewise it can be used as person detection robot. This the prototype of that kind. Here we use simple circuit to detect the human is dead or alive. It is more important to identify and rescue the live persons when natural disaster situations.

This circuit is designed with AT89C51 microcontroller which is a basic microcontroller. Here we use PIR(Passive Infrared ) sensor to detect the motion. The robot can move in all directions. It is a wireless RF controlled robot.

Txr PART:-

          The transmitter part is shown in fig.1 it designed with HT12E Encoder and 4 push buttons. Whenever the user presses the buttons it generates 12-bit data which contains 8-bit address can set and 4 data bits. These data is transmitted to the robot by the RF transmitter which is running at 433MHz frequency. For each button pressed it generates a different code. The entire Transmitter circuit requires 5v DC supply.

Rxr PART:-

          This  contains the RF receiver and its output to the decoder. The decoder here we should use the HT12D to decode the received data. The output of the decoder is 4-bit data which is generated at the transmitter level when the  switch pressed. For motor operations we required to write the C code. Detection of  human is manual control. The commands can be passed to the robot whenever we want switch the detection. Here I used forward and backward buttons to control the detection operation. For this we need to stop the robot at doubted place and press the forward and backward buttons at a time. If the PIR detects motion then the controller sends  high input to the  buzzer to indicate that the person is alive. To smoothen the motor operations and currents we use L293D IC. These 60 RPM DC motors requires a voltage of 12V and it can be provided by lead acid battery.

          Assemble the circuit on a general purpose PCB. And arrange it on robotic structured cabinet. This was practically implemented and tested.  

                                                     Fig.1  Receiver part

Fig.2 Transmitter part

This circuit can detect motion with the help of PIR sensor, it is a simple and well working circuit. It was tested practically.

The source code is:

#include<reg51.h>

sfr rfr=0x90;

sfr mtr=0xB0;

sbit pir=P2^0;

sbit buz=P2^3;

void detection(void);

void main()

{

 rfr=0xFF;

 buz=0;

 while(1)

  {

   if(rfr==0x0E)

    {

  mtr=0x05;

  }

 else if(rfr==0x0D)

  {

   mtr=0x0A;

   }

 else if(rfr==0x0B)

  {

   mtr=0x02;

   }

 else if(rfr==0x07)

   {

    mtr=0x08;

    }

 else if(rfr==0x0C)

   {

   detection();

  }

   else if(rfr==0x0F)

    {

  mtr=0x00;

  buz=0;

   }

  else

      mtr=0x00;

   buz=0;

 }

 }

 void detection()

 {

 unsigned int i;

   mtr=0x00;

    if(pir==1)

     {

     buz=1;

     for(i=0;i<200;i++);   

      }

    else

       buz=0;

}