L298N_Jetson.cpp

/*
 * MIT License
 */

/* 
 * File:   L298N_Jetson.cpp
 * Author: josh
 * 
 * Created on May 23, 2020, 12:58 AM
 */

#include "L298N_Jetson.hpp"
#define DEBUG
L298N_Jetson::L298N_Jetson() = default;

L298N_Jetson::~L298N_Jetson() {
    
    this->Drive_PWM->stop();
    if (this->setup){
        GPIO::cleanup();
    }
};

L298N_Jetson::L298N_Jetson(const int EnablePin,
        const int IN1, const int IN2) {
    this->Enable = EnablePin;
    this->IN1 = IN1;
    this->IN2 = IN2;
    this->pwmVal = 0;
    GPIO::setmode(GPIO::BOARD);
    GPIO::setup(this->IN1, GPIO::OUT,GPIO::LOW);
    GPIO::setup(this->IN2, GPIO::OUT,GPIO::LOW);
    GPIO::setup(this->Enable, GPIO::OUT, GPIO::HIGH);
    this->Drive_PWM = std::make_shared<GPIO::PWM>(this->Enable, 50);
    this->setup = true;
    // approximately 50hz is the correct frequency for the L298N board
}

L298N_Jetson::L298N_Jetson(const int pinIN1, const int pinIN2) {
    this->IN1 = IN1;
    this->IN2 = IN2;
    this->pwmVal = 0;
    GPIO::setmode(GPIO::BOARD);
    GPIO::setup(this->IN1, GPIO::OUT,GPIO::LOW);
    GPIO::setup(this->IN2, GPIO::OUT,GPIO::LOW);
    this->setup = true;

}

L298N_Jetson::L298N_Jetson(std::shared_ptr<GPIO::PWM> drive, const int IN1, 
        const int IN2, const bool setup, const unsigned short minInput, 
        const unsigned short maxInput){
    this->Drive_PWM = drive;
    this->IN1 = IN1;
    this->IN2 = IN2;
    this->pwmVal = 0;
    this->minInput = minInput;
    this->maxInput = maxInput;
    GPIO::setup(this->IN1, GPIO::OUT,GPIO::LOW);
    GPIO::setup(this->IN2, GPIO::OUT,GPIO::LOW);
    this->setup = false; // this tells the object we didn't create the PWM object and thus can't destroy it or stop PWM
                        // The argument doesn't matter, we have to have another argument so the override doesn't collide with
                        // the other constructor
}

void L298N_Jetson::setSpeed(const unsigned short pwmVal){
#ifdef DEBUG
    std::cout << "L298N set speed commanded pwmval: " << pwmVal << "mapped value: " << map(pwmVal) << std::endl;
#endif
    this->pwmVal = map(pwmVal);
}
const unsigned short L298N_Jetson::getSpeed(){
    return pwmVal;
}
void L298N_Jetson::forward(){
        GPIO::output(this->IN1, GPIO::HIGH);
        GPIO::output(this->IN2, GPIO::LOW);
        run();
}
void L298N_Jetson::backward(){
        GPIO::output(this->IN1, GPIO::LOW);
        GPIO::output(this->IN2, GPIO::HIGH);
        run();
}
void L298N_Jetson::run(){
#ifdef DEBUG
    std::cout << " L298N run speed: " << this->pwmVal << std::endl;
#endif
    this->Drive_PWM->start(this->pwmVal, 50) ;
    //important -- you need to send in values from [0, 100].  These are a percentage
    //a percentage for the GPIO library
}
void L298N_Jetson::stop(){
        GPIO::output(this->IN1, GPIO::LOW);
        GPIO::output(this->IN2, GPIO::LOW);
        this->Drive_PWM->stop();
}

unsigned short L298N_Jetson::map(const unsigned short val) {
    if ((val <= maxInput) && (val >= minInput) && (maxInput != minInput)) {
        // return round( (float)minUs + ((float)(maxUs - minUs) / (float)(mapMax - mapMin)) * (float)(val - mapMin) );
        //f(x) = (x - input_start) / (input_end - input_start) * (output_end - output_start) + output_start
        //            return round( ((float)val - this->minInput)/ ((float)this->maxInput - (float)this->minInput) * (this->maxSpeed - this->minSpeed) + this->minSpeed);
        return (val - this->minInput) * (this->maxSpeed - this->minSpeed) / (this->maxInput - this->minInput) + this->minSpeed;
    } else {
        return 0;
    }
}