Servo Motor Controlled CCTV Camera

The design is a simple PIC based servo motor controlled CCTV camera which will use a joystick to control the direction of the camera. The microcontroller used is pic16f84A which is an 18 pin Integrated Circuit and may be supplied by a 2 to 5.5 Voltage. The motion of the camera is a 2 degrees of freedom, can be side to side which is the left or right direction, and the up or down direction. 

CIRCUIT DESCRIPTION

The  power supply used is a fixed 5 volts since the Servo motor can only accomodate 3 to 6 volts which is also the same for the PIC microcontroller then the supply is connected to pin 14 of the PIC microcontroller. Capacitors of 22pF are used to increase the stability of the oscillator which is then connected to ground and to the crystal of 8Mhz which will serve as the clock frequency and is connected to pin 16 and 15 which is the clock in and clock out respectively. The joystick is connected to a resistor to enhance stability of the signal. The joystick is connected to pins 1, 2, 17,  18 which serves as the input of the design, and in Vcc. Pin 17 is for the upward motion, 18 for the downward, 1 for the right, and lastly pin 2 for the left motion.

The output pulse of the portb pin0 of our microcontroller is the input pulse of our servo no.1,and the output pulse of the portb pin4 of our microcontroller is the input pulse of our servo no.2.

If the pulse is 1.5ms on and 18.5ms off the servo motor goes to its 0^o.

If the pulse is 2.5ms on and 18.5ms off the servo motor goes to its +90^o.

If the pulse is 0.5ms on and 18.5ms off the servo motor goes to its -90^o.

Source code

int a=150;

int b=150;

void main() {

TRISA=0xff;                     //set portA as input ports

TRISB=0x00;                     //set portB as output ports

while(1){

PORTB=0x01;                     //make portB pin0 high

vdelay_ms(a/100);               //maintain portB pin0 high for a/100 ms

PORTB=0x10;                     //make portB pin4 high

vdelay_ms(b/100);               //maintain portB pin4 high for b/100 ms

PORTB=0x00;                     //make all portB low

delay_ms(37/2);                 //maintain all portB low for 18.5 ms

if(RA0_bit){                    //when portA pin0 is pressed

if(a>=250) continue;            //set maximum value for a=250

a=a+10;                         //increment a=a+10

}

if(RA1_bit){                    //when portA pin1 is pressed

if(a<=50) continue;             //set minimum value for a=50

a=a-10;                         //decrement a=a-10

}

if(RA2_bit){                    //when portA pin2 is pressed

if(b>=250) continue;            //set maximum value for b=250

b=b+10;                         //increment b=b+10

}

if(RA3_bit){                   //when portA pin3 is pressed

if(b<=50) continue;            //set minimum value for b=50

b=b-10;                        //decrement b=b-10

}

}

}