Default mbed pwm doesn't have enough resolution at high frequencies, thats why I implemented VNH5019 Motor carrier with FastPWM.

Dependencies:   FastPWM

Fork of VNH5019 by IEEE RAS METU

VNH5019.h

Committer:
mbedoguz
Date:
2018-03-15
Revision:
12:fee8aa385836
Parent:
11:6902db5e7978
Child:
13:414b463160ef

File content as of revision 12:fee8aa385836:

#include <mbed.h>
#include <FastPWM.h>

class VNH5019
{
    public:
        VNH5019(PinName INA_, PinName INB_, PinName ENDIAG_, PinName CS_, PinName PWM_);
        
        // set motor speed from -1.0 to +1.0
        void speed(double Speed);

        // stop (no current to the motors)
        void stop();        
    
        // Brake, with strength 0..1
        void brake(float Brake);

        // returns the current through the motor, in mA
        float get_current_mA();

        // returns true if there has been a fault
        bool is_fault();

        // Clears the fault condition
        // PRECONDITION: is_fault()
        void clear_fault();

        // disable the motor, and set outputs to zero.  This is a low power mode.
        void disable();

        // enable the motor.        
        void enable();
        
        // set the PWM period of oscillation in seconds
        void set_pwm_period(int p)
        { PWM.period_us(p); }

    private:
        void init();

        DigitalOut   INA;
        DigitalOut   INB;
        AnalogIn     CS;
        FastPWM      PWM;
};        

// Helper class for the Pololu dual VNH5019 motor shield.
// The default constructor uses the default arduino pins.
// The motors can be accessed either by .m1 or .m2, or by operator()(i) where i is 1 or 2.
class DualVNH5019MotorShield
{
   public:
      // default pin selection
      DualVNH5019MotorShield(); // Default pin selection.

                              // User-defined pin selection. 
      DualVNH5019MotorShield(PinName INA1_, PinName INB1_, PinName ENDIAG1_, PinName CS1_, PinName PWM1_,
                             PinName INA2_, PinName INB2_, PinName ENDIAG2_, PinName CS2_, PinName PWM2_);
    
      // returns the given motor object, 1 or 2.
      VNH5019& operator()(int m);

      VNH5019 m1;
      VNH5019 m2;
};

inline
void VNH5019::stop()
{
    INA = 0;
    INB = 0;
    PWM = 0.0;
}

inline
void VNH5019::brake(float Brake)
{
   // normalize Brake to 0..1
   if (Brake < 0)
      Brake = -Brake;
   if (Brake > 1.0)
      Brake = 1.0;

   INA = 0;
   INB = 0;
   PWM = Brake;
}

inline
float VNH5019::get_current_mA()
{
   // Scale is 210mV per A
   // Scale factor is 3.3 / 0.210 = 15.7142
   return CS.read()*15.7142;
}

inline
bool VNH5019::is_fault()
{
  return false;
}

inline
void VNH5019::disable()
{
}

inline    
void VNH5019::enable()
{
}