This is a demonstration of a military application in which the system automatically launches a missile when any object is detected and comes within range. In the current system, there is a microwave RADAR that detects any object and immediately fires the missile to fire the target.
Here in the given system, it uses an ultrasonic sensor to detect any object. The sensor scans a full 360 ° circle continuously rotating and when it detects any object at a distance of 2 feet (60 cm), launch the missile. It is built using an AT89C51 microcontroller. It also uses LCD to display a different message as well as the distance of an object.
Circuit description
As shown in the figure, the circuit is constructed with four main components, the microcontroller AT89C51, the motor controller chip L293D, the LCD 16x2 and HC-SR04 ultrasonic sensor.
• HC-SR04 has 4-wire interface (1) Vcc (2) Gnd (3) Trip input and (4) echo output. Vcc pin is given +5 V, earth is connected to ground. The trigger input is connected to pin P3.6 and the echo pin is connected to P3.4 pin
• The pins P2.0 to P2.3 of the P2 port drive two DC motors through the L293D chip. The four inputs IN1 to IN4 of L293D are connected to P2.0 to P2.3 and OUT4 OUT1 are operating two motors as shown
• The D0 - D7 LCD data pins are connected to the P0 port. The control pins Rs and En are connected to P2.6 and P2.7, respectively. RW is grounded to allow LCD writing provided
• A 1K pot connects to the VEE pin as shown for varying LCD contrasts
• A 12 MHz crystal is connected to glass input pins along with two 33 pF capacitors
• a capacitor 100 nF between Vcc and pin reset to provide the power-on reset and a switch is connected in parallel with the capacitor to provide a manual reset Connects