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

Committer:
mbedoguz
Date:
Sun Jan 08 13:08:34 2017 +0000
Revision:
6:c8343fa0f3b4
Parent:
5:b5f360a16354
Child:
7:76af111bfff3
Changed constant to make it in mA

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ianmcc 0:5d3ab0ea7f27 1 #include <mbed.h>
ianmcc 0:5d3ab0ea7f27 2
ianmcc 1:5e8d9ed18f0f 3 class VNH5019
ianmcc 1:5e8d9ed18f0f 4 {
ianmcc 1:5e8d9ed18f0f 5 public:
ianmcc 1:5e8d9ed18f0f 6 VNH5019(PinName INA_, PinName INB_, PinName ENDIAG_, PinName CS_, PinName PWM_);
ianmcc 1:5e8d9ed18f0f 7
ianmcc 1:5e8d9ed18f0f 8 // set motor speed from -1.0 to +1.0
ianmcc 1:5e8d9ed18f0f 9 void speed(float Speed);
ianmcc 1:5e8d9ed18f0f 10
ianmcc 1:5e8d9ed18f0f 11 // stop (no current to the motors)
ianmcc 1:5e8d9ed18f0f 12 void stop();
ianmcc 1:5e8d9ed18f0f 13
ianmcc 1:5e8d9ed18f0f 14 // Brake, with strength 0..1
ianmcc 1:5e8d9ed18f0f 15 void brake(float Brake);
ianmcc 1:5e8d9ed18f0f 16
ianmcc 1:5e8d9ed18f0f 17 // returns the current through the motor, in mA
ianmcc 1:5e8d9ed18f0f 18 float get_current_mA();
ianmcc 1:5e8d9ed18f0f 19
ianmcc 1:5e8d9ed18f0f 20 // returns true if there has been a fault
ianmcc 1:5e8d9ed18f0f 21 bool is_fault();
ianmcc 1:5e8d9ed18f0f 22
ianmcc 1:5e8d9ed18f0f 23 // Clears the fault condition
ianmcc 1:5e8d9ed18f0f 24 // PRECONDITION: is_fault()
ianmcc 1:5e8d9ed18f0f 25 void clear_fault();
ianmcc 1:5e8d9ed18f0f 26
ianmcc 1:5e8d9ed18f0f 27 // disable the motor, and set outputs to zero. This is a low power mode.
ianmcc 1:5e8d9ed18f0f 28 void disable();
ianmcc 1:5e8d9ed18f0f 29
ianmcc 1:5e8d9ed18f0f 30 // enable the motor.
ianmcc 1:5e8d9ed18f0f 31 void enable();
ianmcc 2:d670a4b999ab 32
ianmcc 2:d670a4b999ab 33 // set the PWM period of oscillation in seconds
ianmcc 2:d670a4b999ab 34 void set_pwm_period(float p)
ianmcc 2:d670a4b999ab 35 { PWM.period(p); }
ianmcc 1:5e8d9ed18f0f 36
ianmcc 1:5e8d9ed18f0f 37 private:
ianmcc 2:d670a4b999ab 38 void init();
ianmcc 1:5e8d9ed18f0f 39
ianmcc 1:5e8d9ed18f0f 40 DigitalOut INA;
ianmcc 1:5e8d9ed18f0f 41 DigitalOut INB;
ianmcc 1:5e8d9ed18f0f 42 DigitalInOut ENDIAG;
ianmcc 1:5e8d9ed18f0f 43 AnalogIn CS;
ianmcc 1:5e8d9ed18f0f 44 PwmOut PWM;
ianmcc 1:5e8d9ed18f0f 45 };
ianmcc 1:5e8d9ed18f0f 46
ianmcc 1:5e8d9ed18f0f 47 // Helper class for the Pololu dual VNH5019 motor shield.
ianmcc 1:5e8d9ed18f0f 48 // The default constructor uses the default arduino pins.
ianmcc 1:5e8d9ed18f0f 49 // The motors can be accessed either by .m1 or .m2, or by operator()(i) where i is 1 or 2.
ianmcc 0:5d3ab0ea7f27 50 class DualVNH5019MotorShield
ianmcc 0:5d3ab0ea7f27 51 {
ianmcc 0:5d3ab0ea7f27 52 public:
ianmcc 0:5d3ab0ea7f27 53 // default pin selection
ianmcc 0:5d3ab0ea7f27 54 DualVNH5019MotorShield(); // Default pin selection.
ianmcc 0:5d3ab0ea7f27 55
ianmcc 0:5d3ab0ea7f27 56 // User-defined pin selection.
ianmcc 0:5d3ab0ea7f27 57 DualVNH5019MotorShield(PinName INA1_, PinName INB1_, PinName ENDIAG1_, PinName CS1_, PinName PWM1_,
ianmcc 0:5d3ab0ea7f27 58 PinName INA2_, PinName INB2_, PinName ENDIAG2_, PinName CS2_, PinName PWM2_);
ianmcc 0:5d3ab0ea7f27 59
ianmcc 1:5e8d9ed18f0f 60 // returns the given motor object, 1 or 2.
ianmcc 1:5e8d9ed18f0f 61 VNH5019& operator()(int m);
ianmcc 0:5d3ab0ea7f27 62
ianmcc 1:5e8d9ed18f0f 63 VNH5019 m1;
ianmcc 1:5e8d9ed18f0f 64 VNH5019 m2;
ianmcc 0:5d3ab0ea7f27 65 };
ianmcc 0:5d3ab0ea7f27 66
ianmcc 5:b5f360a16354 67 inline
ianmcc 5:b5f360a16354 68 void VNH5019::stop()
ianmcc 5:b5f360a16354 69 {
ianmcc 5:b5f360a16354 70 INA = 0;
ianmcc 5:b5f360a16354 71 INB = 0;
ianmcc 5:b5f360a16354 72 PWM = 0.0;
ianmcc 5:b5f360a16354 73 }
ianmcc 5:b5f360a16354 74
ianmcc 5:b5f360a16354 75 inline
ianmcc 5:b5f360a16354 76 void VNH5019::brake(float Brake)
ianmcc 5:b5f360a16354 77 {
ianmcc 5:b5f360a16354 78 // normalize Brake to 0..1
ianmcc 5:b5f360a16354 79 if (Brake < 0)
ianmcc 5:b5f360a16354 80 Brake = -Brake;
ianmcc 5:b5f360a16354 81 if (Brake > 1.0)
ianmcc 5:b5f360a16354 82 Brake = 1.0;
ianmcc 5:b5f360a16354 83
ianmcc 5:b5f360a16354 84 INA = 0;
ianmcc 5:b5f360a16354 85 INB = 0;
ianmcc 5:b5f360a16354 86 PWM = Brake;
ianmcc 5:b5f360a16354 87 }
ianmcc 5:b5f360a16354 88
ianmcc 5:b5f360a16354 89 inline
ianmcc 5:b5f360a16354 90 float VNH5019::get_current_mA()
ianmcc 5:b5f360a16354 91 {
ianmcc 5:b5f360a16354 92 // Scale is 144mV per A
ianmcc 5:b5f360a16354 93 // Scale factor is 3.3 / 0.144 = 22.916667
mbedoguz 6:c8343fa0f3b4 94 return CS.read() * 22916.667;
ianmcc 5:b5f360a16354 95 }
ianmcc 5:b5f360a16354 96
ianmcc 5:b5f360a16354 97 inline
ianmcc 5:b5f360a16354 98 bool VNH5019::is_fault()
ianmcc 5:b5f360a16354 99 {
ianmcc 5:b5f360a16354 100 return !ENDIAG;
ianmcc 5:b5f360a16354 101 }
ianmcc 5:b5f360a16354 102
ianmcc 5:b5f360a16354 103 inline
ianmcc 5:b5f360a16354 104 void VNH5019::disable()
ianmcc 5:b5f360a16354 105 {
ianmcc 5:b5f360a16354 106 ENDIAG.output();
ianmcc 5:b5f360a16354 107 ENDIAG.write(0);
ianmcc 5:b5f360a16354 108 }
ianmcc 5:b5f360a16354 109
ianmcc 5:b5f360a16354 110 inline
ianmcc 5:b5f360a16354 111 void VNH5019::enable()
ianmcc 5:b5f360a16354 112 {
ianmcc 5:b5f360a16354 113 ENDIAG.input();
ianmcc 5:b5f360a16354 114 }