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:
Thu Mar 15 20:51:20 2018 +0000
Revision:
13:414b463160ef
Parent:
12:fee8aa385836
Child:
14:193c422498bf
a

Who changed what in which revision?

UserRevisionLine numberNew contents of line
ianmcc 0:5d3ab0ea7f27 1 #include <mbed.h>
mbedoguz 8:1458b4da7e56 2 #include <FastPWM.h>
ianmcc 0:5d3ab0ea7f27 3
ianmcc 1:5e8d9ed18f0f 4 class VNH5019
ianmcc 1:5e8d9ed18f0f 5 {
ianmcc 1:5e8d9ed18f0f 6 public:
ianmcc 1:5e8d9ed18f0f 7 VNH5019(PinName INA_, PinName INB_, PinName ENDIAG_, PinName CS_, PinName PWM_);
ianmcc 1:5e8d9ed18f0f 8
ianmcc 1:5e8d9ed18f0f 9 // set motor speed from -1.0 to +1.0
mbedoguz 8:1458b4da7e56 10 void speed(double Speed);
ianmcc 1:5e8d9ed18f0f 11
ianmcc 1:5e8d9ed18f0f 12 // stop (no current to the motors)
ianmcc 1:5e8d9ed18f0f 13 void stop();
ianmcc 1:5e8d9ed18f0f 14
ianmcc 1:5e8d9ed18f0f 15 // Brake, with strength 0..1
ianmcc 1:5e8d9ed18f0f 16 void brake(float Brake);
ianmcc 1:5e8d9ed18f0f 17
ianmcc 1:5e8d9ed18f0f 18 // returns the current through the motor, in mA
ianmcc 1:5e8d9ed18f0f 19 float get_current_mA();
ianmcc 1:5e8d9ed18f0f 20
ianmcc 1:5e8d9ed18f0f 21 // returns true if there has been a fault
ianmcc 1:5e8d9ed18f0f 22 bool is_fault();
ianmcc 1:5e8d9ed18f0f 23
ianmcc 1:5e8d9ed18f0f 24 // Clears the fault condition
ianmcc 1:5e8d9ed18f0f 25 // PRECONDITION: is_fault()
ianmcc 1:5e8d9ed18f0f 26 void clear_fault();
ianmcc 1:5e8d9ed18f0f 27
ianmcc 1:5e8d9ed18f0f 28 // disable the motor, and set outputs to zero. This is a low power mode.
ianmcc 1:5e8d9ed18f0f 29 void disable();
ianmcc 1:5e8d9ed18f0f 30
ianmcc 1:5e8d9ed18f0f 31 // enable the motor.
ianmcc 1:5e8d9ed18f0f 32 void enable();
ianmcc 2:d670a4b999ab 33
ianmcc 2:d670a4b999ab 34 // set the PWM period of oscillation in seconds
mbedoguz 8:1458b4da7e56 35 void set_pwm_period(int p)
mbedoguz 8:1458b4da7e56 36 { PWM.period_us(p); }
ianmcc 1:5e8d9ed18f0f 37
ianmcc 1:5e8d9ed18f0f 38 private:
ianmcc 2:d670a4b999ab 39 void init();
ianmcc 1:5e8d9ed18f0f 40
ianmcc 1:5e8d9ed18f0f 41 DigitalOut INA;
ianmcc 1:5e8d9ed18f0f 42 DigitalOut INB;
ianmcc 1:5e8d9ed18f0f 43 AnalogIn CS;
mbedoguz 8:1458b4da7e56 44 FastPWM 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 {
mbedoguz 7:76af111bfff3 92 // Scale is 210mV per A
mbedoguz 7:76af111bfff3 93 // Scale factor is 3.3 / 0.210 = 15.7142
mbedoguz 13:414b463160ef 94 return CS.read();//*15.7142;
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 {
mbedoguz 11:6902db5e7978 100 return false;
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 }
ianmcc 5:b5f360a16354 107
ianmcc 5:b5f360a16354 108 inline
ianmcc 5:b5f360a16354 109 void VNH5019::enable()
ianmcc 5:b5f360a16354 110 {
ianmcc 5:b5f360a16354 111 }