File content as of revision 4:4dafa4113982:

#include "mbed.h"
#include "rtos.h"

#define AUTO 1
#define MANUAL 0

extern Serial Camera;
extern bool Mode;

void UpdateCamera (float ZoomDemand, float FocusDemand)
{
    static signed int LastZoom = 0;
    static signed int LastFocus = 0;

    // The ZoomDemand value passed to this function is a raw read of the AnalogIn object
    ZoomDemand -= 0.5;                          // Shift the raw value to the centre-tap
    ZoomDemand *= -14;                          // Scale to get in the -7 to +7 range
    int Zoom = (int)ZoomDemand;                 // Cast to an int

    // Do the same thing for Focus
    FocusDemand *= 0x7000;                      // Scale to the range of 0 to 28672
    FocusDemand += 0x0800;                      // Add a shift of 2048 to get to 2048 to 30720
    int Focus = (int)FocusDemand & 0xFFC0;      // Knock off the last 6 bits of noise!

    // See if we need to move the Camera Zoom Position
    if(Zoom != LastZoom) {

        // First calculate the new Zoom Setting
        if (Zoom > 0) {
            // Send the tele command
            Zoom += 0x20;
        } else if(Zoom < 0) {
            // Send the wide command
            Zoom *= -1;
            Zoom += 0x30;
        }
        LastZoom = Zoom;                        // Update the last know Focus Demand for next time

        // Send first 4 characters (always the same)
        Camera.putc(0x81);
        Camera.putc(0x01);
        Camera.putc(0x04);
        Camera.putc(0x07);
        Camera.putc(Zoom);
        Camera.putc(0xFF);
    }

    // Now see if we need to move the Camera Focus Position
    if(Mode == MANUAL && Focus != LastFocus) {
        Camera.putc(0x81);                      // Camera
        Camera.putc(0x01);
        Camera.putc(0x04);
        Camera.putc(0x48);                      // Direct focus cmd
        Camera.putc((Focus & 0xF000)>>12);      // p variable
        Camera.putc((Focus & 0x0F00)>>8);       // q variable
        Camera.putc((Focus & 0x00F0)>>4);       // r variable
        Camera.putc(Focus & 0x000F);            // s variable
        Camera.putc(0xFF);

        LastFocus = Focus;                      // Update the last know Focus Demand for next time
    }

    // Return the current Zoom position    
    Camera.putc(0x81);                  // Address byte from host to camera - 0x81
    Camera.putc(0x09);                  // Zoom position inquiry - 8x 09 04 47 ff
    Camera.putc(0x04);
    Camera.putc(0x47);
    Camera.putc(0xFF);                  // Terminator byte - all 1s
    
}