File content as of revision 0:79dc2fa0defa:

#include "mbed.h"
#include "Servo.h"
#define NUMREADINGS 1000;
AnalogIn A_In(p20);
Serial pc(USBTX, USBRX);                        // USB serial interface
Servo cr_srv(p21);                              // continuous rotation hobby servo
Servo std_srv(p22);                             // standard hobby servo
#define CR_SCALE 12.0
void init_servo() {
                                                // calibrate the servos for +/-5ms over +/-45deg
 cr_srv.calibrate(0.0005,45);
 std_srv.calibrate(0.0005,45);
}

int main() {
    
float pos_val=0.5;                              // variable to hold position values
float AIreadings=0.0;                           // variable to hold cummulative analouge values
float cr_srv_cmd=0.5;                           // continuous rotation servo command value (range: 0.0 - 1.0)
float std_srv_cmd=0.5;                          // standard servo command value (range: 0.0 - 1.0)
                                                
// set the USB serial interface baud rate
pc.baud(921600);

init_servo();

while(1) {
    AIreadings = 0;
    for (int i=0; i<NUMREADINGS/2; i++) {
    AIreadings = AIreadings + A_in.read();
}
    for (int i=NUMREADINGS/2; i<NUMREADINGS; i++) {
    AIreadings = AIreadings + A_in.read();
}
pos_val = AIreadings/NUMREADINGS;
 // use a sin function to create an oscillating servo postion with values
 // between 0.0 and 1.0 for the standard servo
 std_srv_cmd = sin(pos_val*2*3.14159)/2.0+0.5;
 // use a smaller scale for the continuous rotation servo, due to its limited sensitivity
 cr_srv_cmd = sin(pos_val*2*3.14159)/CR_SCALE+0.515;

 // sernd the servo command to the servos themselves
 cr_srv.write(cr_srv_cmd); // write to the continuous rotation servo
 std_srv.write(std_srv_cmd); // write to the standard servo

 // export the readings to a terminal program via the USB cable
 pc.printf("pos value: %6.4f, cr servo: %6.4f std servo: %6.4f\r", pos_val, cr_srv_cmd,
 std_srv_cmd);

 pos_val = pos_val + step_size;                  // increment/decrement the position
 if (pos_val > 1.0) pos_val = 0.0;               // if the position is out of bounds, reset the pos value

 wait(0.250); // wait for 0.25s to give time for the display to show
 }
}