#include <MX1508.h>

#define PINA 9
#define PINB 10
#define NUMPWM 2
// MX1508 schematics(in Chinese) can be found here at: http://sales.dzsc.com/486222.html
/*
 * MX1508(uint8_t pinIN1, uint8_t pinIN2, DecayMode decayMode, NumOfPwmPins numPWM);
 * DecayMode must be FAST_DECAY or SLOW_DECAY,
 * NumOfPwmPins, either use 1 or 2 pwm. 
 * I recommend using 2 pwm pins per motor so spinning motor forward and backward gives similar response.
 * if using 1 pwm pin, make sure its pinIN1, then set pinIN2 to any digital pin. I dont recommend this setting because 
 * we need to use FAST_DECAY in one direction and SLOW_DECAY for the other direction.  
 */
MX1508 motorA(PINA,PINB, FAST_DECAY, NUMPWM);

void setup() {
  Serial.begin(115200);
}
/*
 * Ramp up to pwm = 100, by increasing pwm by 1 every 50 millisecond. 
 * then ramp down to pwm = -100, by decreasing pwm every 50 millisecond.
 * positive value pwm results in forward direction.
 * negative value pwm results in opposite direction. 
 */
void loop() {
  // put your main code here, to run repeatedly:
  static unsigned long lastMilli = 0;
  static bool cwDirection = true; // assume initial direction(positive pwm) is clockwise
  static int pwm = 1;
  
  if(millis()-lastMilli > 50){ // every 50 millisecond
      if (cwDirection && pwm++ > 100 ) {  
        cwDirection = false;
      } else if (!cwDirection && pwm-- < -100) {
        cwDirection =  true;
      } 
    motorA.motorGo(pwm);
    lastMilli = millis();
    Serial.println(motorA.getPWM()); // we can just print pwm but just showing that member function getPWM() works.
  }

}