File content as of revision 10:ca6f2769964e:

#include "mbed.h"
#include "rtos.h"
#include "Servo.h"
#include "C12832.h"

Servo tiltServo(p21);
Servo panServo(p22);
Serial pc(USBTX, USBRX);
Servo vertServo(p23);
AnalogIn sonar(p19);
Mutex mutexIn;
Mutex mutexOut;
 
AnalogIn p1(p19);
AnalogIn p2(p20);

// Global variables
float corHoriz = 0; // horizontal variable arrives from OpenCV
float corVert = 0; // vertical variable arrives from OpenCV
float distance = 0;
float outVert; // rr
float outTilt;
float outHoriz;
C12832 lcd(p5, p7, p6, p8, p11);// lcd is an object from class c12832 initialised by p5,p7....

/* Thread Serial 1 - handles the output data from the control thread, and pass to the servo.
    @update s1, s2 */
void serial_thread(void const *args) {
    while (true) {
        pc.scanf("%f,%f", &corHoriz, &corVert);// read from serial port the data
    }
}
 
/* Thread LCD 2 - handles the input data from the sonar sensor, and display on the LCD screen.
    @update inData */
void lcd_thread(void const *args) {
    while (true) {
        // Display values on the LCD screen
        lcd.cls();          // clear the display
        lcd.locate(0,5);    // the location where you want your charater to be displayed
        lcd.printf("Hor: %0.3f", corHoriz);
        lcd.locate(0,20);    // the location where you want your charater to be displayed
        lcd.printf("Ver: %0.3f", corVert);
        Thread::wait(250);
    }
}

/* Thread Control 3 - handles the input data from the sonar sensor, and display on the LCD screen.
    @update inData */
void control_thread(void const *args) {
    while (true) {
        mutexIn.lock();
        float differ;
        differ = exp(corVert + sonar * outTilt) / (1 + exp(corVert + sonar * outTilt));
        if (corVert > .5) { // check if face is below the half of the camera view
            if (outTilt > .5) { // check if lamp head is facing down
                // moves lamp down by the fraction of the difference from the middle
            }
        }
        mutexIn.unlock();
        Thread::wait(25);
    }
}

/* Thread Servo 4 - handles the output data from the control thread, and pass to the servo.
    @update s1, s2 */
void servo_thread(void const *args) {
    while (true) {
        mutexOut.lock();
        tiltServo = outTilt;
        panServo = outHoriz;
        vertServo = outVert;
        mutexOut.unlock();
        Thread::wait(200);
    }
}

int main() {
    Thread thread_1(serial_thread); // Start Serial Thread
    Thread thread_2(lcd_thread); // Start LCD Thread
    Thread thread_3(control_thread); // Start Servo Thread
    Thread thread_4(servo_thread); // Start Servo Thread
    while(1) {
        wait(1);
    }
}