File content as of revision 0:68133f5cdfa0:

/* MeArm Servo Calibration

(c) Dr Craig A. Evans, University of Leeds

July 2017

*/

#include "mbed.h"

// pins for potentiometers
AnalogIn m_pot(p17);
AnalogIn l_pot(p18);
AnalogIn r_pot(p19);
AnalogIn c_pot(p20);

// PWM pins for servos
PwmOut m_servo(p21);
PwmOut l_servo(p22);
PwmOut r_servo(p23);
PwmOut c_servo(p24);

int main()
{

    m_servo.period_ms(20);  // 20 ms = 50 Hz
    // all PWM channels share the same period and so only need to set one of them

    // keep looping forever
    while(1) {

        // read val in range 0.0 to 1.0
        float m_pot_val = m_pot.read();
        // create a pulse-width value in range 400 to 3000us
        int m_pot_pulse_us = int(400.0 + m_pot_val*2600.0);  
        m_servo.pulsewidth_us(m_pot_pulse_us);

        // repeat for other servos
        float l_pot_val = l_pot.read();
        int l_pot_pulse_us = int(600.0 + l_pot_val*2600.0);  
        l_servo.pulsewidth_us(l_pot_pulse_us);

        float r_pot_val = r_pot.read();
        int r_pot_pulse_us = int(600.0 + r_pot_val*2600.0); 
        r_servo.pulsewidth_us(r_pot_pulse_us);

        float c_pot_val = c_pot.read();
        int c_pot_pulse_us = int(600.0 + c_pot_val*2600.0); 
        c_servo.pulsewidth_us(c_pot_pulse_us);
        
        // print the values to the PC terminal
        printf("M=%i L=%i R=%i C=%i\n",m_pot_pulse_us,l_pot_pulse_us,r_pot_pulse_us,c_pot_pulse_us);

        // delay as we don't want to update the servos too often
        wait_ms(200);
    }
}