Library for driving a motor with one PWM and one DIR signal using PI control.
Fork of Motor2 by
motor.cpp
- Committer:
- Reiko
- Date:
- 2013-09-14
- Revision:
- 2:3faf5dcde08f
- Parent:
- 1:c97f8bcd6c0f
- Child:
- 3:94db629c0a83
File content as of revision 2:3faf5dcde08f:
#include "motor.h" Motor::Motor(PinName PWMpin, PCA9555 *ioExt, unsigned int dir1Pin, unsigned int dir2Pin, PinName encA, PinName encB) : pwm(PWMpin), extIO(ioExt), dir1(dir1Pin), dir2(dir2Pin), qed(encA, encB) { PwmOut pwm(PWMpin); pwm.period_ms(1); setPoint = 0; pMulti = 2.0; iMulti = 0.01; dMulti = 1; error = 0.0; prevError = 0.0; P = 0.0; I = 0.0; minPwm = 0.1; currentSpeed = 0; } void Motor::setPWM(float newPWM) { if (newPWM < 0) { pwm = -1 * newPWM; extIO->setPin(dir1); extIO->clearPin(dir2); } else { pwm = newPWM; extIO->clearPin(dir1); extIO->setPin(dir2); } } int Motor::getSpeed() { return currentSpeed; } int Motor::getDecoderCount() { currentSpeed = qed.read(); return currentSpeed; } void Motor::setSpeed(int newSpeed) { setPoint = newSpeed; if (newSpeed == 0) { resetPID(); } } void Motor::pid() { /*int setPoint = 0; float pMulti = 0.1; float iMulti = 0.001; int error = 0; int prevError = 0; float P = 0.0; float I = 0.0;*/ prevError = error; error = (float)(setPoint - getDecoderCount()) / 250.0; //float err = (float)error / 250.0; float minPwmValue = minPwm; if (setPoint == 0) { minPwmValue = 0.0; } else if (setPoint < 0) { minPwmValue = -minPwm; } I += error * iMulti; //constrain integral if (I < -1.0) I = -1.0; if (I > 1.0) I = 1.0; //D = error - prevError; //float newPWMvalue = minPwmValue + error * pMulti + I + dMulti * D; float newPWMvalue = minPwmValue + error * pMulti + I; //constrain pwm if (newPWMvalue < -1.0) newPWMvalue = -1.0; if (newPWMvalue > 1.0) newPWMvalue = 1.0; setPWM(newPWMvalue); } void Motor::resetPID() { error = 0; prevError = 0; P = 0; I = 0; setPoint = 0; pwm = 0; }