Joseph Bradshaw / MotCon

Simple DC motor control commands for driving DC motor conroller with PWM and up to 2 direction signals (complementary). Takes float value from -1.0 to 1.0.

Dependents:   mbed_ES410_simpleSpeedMeasurement mbed_ES20X_V21_Tester

This MotCon motor driver class can be used with a variety of motor driver integrated circuits for driving PM DC motors. The MotCon class is overloaded to accommodate either one or two direction pins and a PwmOut pin for speed control/motor enable .

include the mbed library with this snippet

#include "MotCon.h"     //uses the MotCon.h library for controlling the motor ports

//PC serial connection
Serial pc(USBTX, USBRX);    //tx, rx via USB connection
DigitalOut led(LED1);
MotCon m1(p25, p27);        //uses p25 for PWM and p27 for direction
MotCon m2(p26, p29, p30);   //uses p26 for pwm and p29 and 30 for direction (complimentary)

//------------ Main ------------------------------
int main() {    
    pc.baud(921600);//fast baud rate for USB PC connection
    while(1) {
        //iterate through 2*pi cycles in .01 increments
        for(float cycle=0;cycle<3.14159*2.0;cycle+=.01){
            float m1_dc = .85*sin(cycle);            
            m1.mot_control(m1_dc);
            
            float m2_dc = .85*cos(cycle);
            m2.mot_control(m2_dc);
                        
            pc.printf("cycle=%.3f  m1_dc = %.2f  m1_dc = %.2f\r\n", cycle, m1_dc, m2_dc);
            wait(.01);      //determines period
            led = !led;     //toggle LED1 to indicate activity
        }
    }
}

MotCon.cpp

Committer:
jebradshaw
Date:
2016-05-23
Revision:
1:382121501487
Parent:
0:3ba12980833b
Child:
4:23cd902e1774
Child:
5:3e07f69d8abd

File content as of revision 1:382121501487:

#include "MotCon.h"

//Constructor
MotCon::MotCon(PinName pwm, PinName dir) : _pwm(pwm), _dir(dir) {
    _pwm.period_us(50);
    _pwm = 0.0;
    _dir = 0;
}

// dc is signed duty cycle (+/-1.0)
void MotCon::mot_control(float dc){        
    if(dc>1.0)
        dc=1.0;
    if(dc<-1.0)
        dc=-1.0;
        
    if(dc > 0.001){
        _dir = 0;
        _pwm = dc;
    }
    else if(dc < -0.001){
        _dir = 1;
        _pwm = abs(dc);
    }
    else{
        _dir = 0;
        _pwm = 0.0;
    }      
}

// dc is signed duty cycle (+/-1.0)
void MotCon::mot_control(float dc, int invert){        
    if(dc>1.0)
        dc=1.0;
    if(dc<-1.0)
        dc=-1.0;
        
    if(invert==0){
        if(dc > 0.001){
            _dir = 0;
            _pwm = dc;
        }
        else if(dc < -0.001){
            _dir = 1;
            _pwm = abs(dc);
        }
        else{
            _dir = 0;
            _pwm = 0.0;
        }
    }
    else{
        if(dc > 0.001){
            _dir = 1;
            _pwm = dc;
        }
        else if(dc < -0.001){
            _dir = 0;
            _pwm = abs(dc);
        }
        else{
            _dir = 0;
            _pwm = 0.0;
        }
    }
}