atmega2560_mcu.cpp

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#include "../hardware_api.h"
 
#if defined(__AVR_ATmega2560__)
 
// set pwm frequency to 32KHz
void _pinHighFrequency(const int pin){
  //  High PWM frequency
  //  https://sites.google.com/site/qeewiki/books/avr-guide/timers-on-the-atmega328
  //  https://forum.arduino.cc/index.php?topic=72092.0
   if (pin == 13 || pin == 4  ) {
      TCCR0A = ((TCCR0A & 0b11111100) | 0x01); // configure the pwm phase-corrected mode
      TCCR0B = ((TCCR0B & 0b11110000) | 0x01); // set prescaler to 1
  }
  else if (pin == 12 || pin == 11 )
      TCCR1B = ((TCCR1B & 0b11111000) | 0x01);     // set prescaler to 1
  else if (pin == 10 || pin == 9 )
      TCCR2B = ((TCCR2B & 0b11111000) | 0x01);     // set prescaler to 1
  else if (pin == 5 || pin == 3 || pin == 2) 
      TCCR3B = ((TCCR2B & 0b11111000) | 0x01);    // set prescaler to 1
  else if (pin == 8 || pin == 7 || pin == 6)
      TCCR4B = ((TCCR4B & 0b11111000) | 0x01);    // set prescaler to 1
  else if (pin == 44 || pin == 45 || pin == 46)
      TCCR5B = ((TCCR5B & 0b11111000) | 0x01);    // set prescaler to 1
  
}
 
 
// function setting the high pwm frequency to the supplied pins
// - Stepper motor - 2PWM setting
// - hardware speciffic
void _configure2PWM(long pwm_frequency,const int pinA, const int pinB) {
   //  High PWM frequency
   // - always max 32kHz
  _pinHighFrequency(pinA);
  _pinHighFrequency(pinB);
}
 
// function setting the high pwm frequency to the supplied pins
// - BLDC motor - 3PWM setting
// - hardware speciffic
void _configure3PWM(long pwm_frequency,const int pinA, const int pinB, const int pinC) {
   //  High PWM frequency
   // - always max 32kHz
  _pinHighFrequency(pinA);
  _pinHighFrequency(pinB);
  _pinHighFrequency(pinC);
}
 
// function setting the pwm duty cycle to the hardware 
// - Stepper motor - 2PWM setting
// - hardware speciffic
void _writeDutyCycle2PWM(float dc_a,  float dc_b, int pinA, int pinB){
  // transform duty cycle from [0,1] to [0,255]
  analogWrite(pinA, 255.0*dc_a);
  analogWrite(pinB, 255.0*dc_b);
}
 
// function setting the pwm duty cycle to the hardware 
// - BLDC motor - 3PWM setting
// - hardware speciffic
void _writeDutyCycle3PWM(float dc_a,  float dc_b, float dc_c, int pinA, int pinB, int pinC){
  // transform duty cycle from [0,1] to [0,255]
  analogWrite(pinA, 255.0*dc_a);
  analogWrite(pinB, 255.0*dc_b);
  analogWrite(pinC, 255.0*dc_c);
}
 
// function setting the high pwm frequency to the supplied pins
// - Stepper motor - 4PWM setting
// - hardware speciffic
void _configure4PWM(long pwm_frequency,const int pin1A, const int pin1B, const int pin2A, const int pin2B) {
   //  High PWM frequency
   // - always max 32kHz
  _pinHighFrequency(pin1A);
  _pinHighFrequency(pin1B);
  _pinHighFrequency(pin2A);
  _pinHighFrequency(pin2B); 
}
 
// function setting the pwm duty cycle to the hardware  
// - Stepper motor - 4PWM setting
// - hardware speciffic
void _writeDutyCycle4PWM(float dc_1a,  float dc_1b, float dc_2a, float dc_2b, int pin1A, int pin1B, int pin2A, int pin2B){
  // transform duty cycle from [0,1] to [0,255]
  analogWrite(pin1A, 255.0*dc_1a);
  analogWrite(pin1B, 255.0*dc_1b);
  analogWrite(pin2A, 255.0*dc_2a);
  analogWrite(pin2B, 255.0*dc_2b);
}
 
 
// function configuring pair of high-low side pwm channels, 32khz frequency and center aligned pwm
// supports Arudino/ATmega2560
int _configureComplementaryPair(int pinH, int pinL) {
  if( (pinH == 4 && pinL == 13 ) || (pinH == 13 && pinL == 4 ) ){ 
    // configure the pwm phase-corrected mode
    TCCR0A = ((TCCR0A & 0b11111100) | 0x01);
    // configure complementary pwm on low side
    if(pinH == 13 ) TCCR0A = 0b10110000 | (TCCR0A & 0b00001111) ;
    else TCCR0A = 0b11100000 | (TCCR0A & 0b00001111) ;
    // set prescaler to 1 - 32kHz freq
    TCCR0B = ((TCCR0B & 0b11110000) | 0x01);
  }else if( (pinH == 11 && pinL == 12 ) || (pinH == 12 && pinL == 11 ) ){
    // set prescaler to 1 - 32kHz freq
    TCCR1B = ((TCCR1B & 0b11111000) | 0x01);
    // configure complementary pwm on low side
    if(pinH == 11 ) TCCR1A = 0b10110000 | (TCCR1A & 0b00001111) ;
    else TCCR1A = 0b11100000 | (TCCR1A & 0b00001111) ;
  }else if((pinH == 10 && pinL == 9 ) || (pinH == 9 && pinL == 10 ) ){
    // set prescaler to 1 - 32kHz freq
    TCCR2B = ((TCCR2B & 0b11111000) | 0x01);
    // configure complementary pwm on low side
    if(pinH == 10 ) TCCR2A = 0b10110000 | (TCCR2A & 0b00001111) ;
    else TCCR2A = 0b11100000 | (TCCR2A & 0b00001111) ;
  }else{
    return -1;
  }
  return 0;
}
 
// Configuring PWM frequency, resolution and alignment
// - BLDC driver - 6PWM setting
// - hardware specific
// supports Arudino/ATmega328 
int _configure6PWM(long pwm_frequency, float dead_zone, const int pinA_h, const int pinA_l,  const int pinB_h, const int pinB_l, const int pinC_h, const int pinC_l) {
  //  High PWM frequency
  // - always max 32kHz
  int ret_flag = 0;
  ret_flag += _configureComplementaryPair(pinA_h, pinA_l);
  ret_flag += _configureComplementaryPair(pinB_h, pinB_l);
  ret_flag += _configureComplementaryPair(pinC_h, pinC_l);
  return ret_flag; // returns -1 if not well configured
}
 
// function setting the 
void _setPwmPair(int pinH, int pinL, float val, int dead_time)
{
  int pwm_h = _constrain(val-dead_time/2,0,255);
  int pwm_l = _constrain(val+dead_time/2,0,255);
  
  analogWrite(pinH, pwm_h);
  if(pwm_l == 255 || pwm_l == 0)
    digitalWrite(pinL, pwm_l ? LOW : HIGH);
  else
    analogWrite(pinL, pwm_l);
}
 
// Function setting the duty cycle to the pwm pin (ex. analogWrite())
//  - BLDC driver - 6PWM setting
//  - hardware specific
// supports Arudino/ATmega328 
void _writeDutyCycle6PWM(float dc_a,  float dc_b, float dc_c, float dead_zone, int pinA_h, int pinA_l, int pinB_h, int pinB_l, int pinC_h, int pinC_l){
  _setPwmPair(pinA_h, pinA_l, dc_a*255.0, dead_zone*255.0);
  _setPwmPair(pinB_h, pinB_l, dc_b*255.0, dead_zone*255.0);
  _setPwmPair(pinC_h, pinC_l, dc_c*255.0, dead_zone*255.0);
}
 
#endif