seesaw_servo.cpp

#include "seesaw_servo.h"

#define MIN_PULSE 3277
#define MAX_PULSE 6554

/**************************************************************************/
/*!
    @brief  begin the seesaw. This is only necessary if the seesaw is not
   already started
    @param addr the address to begin on
    @param flow the flow control pin to use
    @returns true on success, false otherwise
*/
/**************************************************************************/
bool seesaw_Servo::begin(uint8_t addr, int8_t flow) {
  return _ss->begin(addr, flow);
}

/**************************************************************************/
/*!
    @brief  attach the given pin to the next free channel, sets pinMode.
    @param pin the pin to use

    @returns 0
*/
/**************************************************************************/
uint8_t seesaw_Servo::attach(int pin) {
  _pin = pin;
  // set frequency to 50 hz
  _ss->setPWMFreq(_pin, 50);
  _attached = true;
  min = MIN_PULSE;
  max = MAX_PULSE;
  return 0;
}

/**************************************************************************/
/*!
    @brief  attach the given pin to the next free channel but also sets min and
   max values for writes.
    @param pin the pin to use
    @param min the minimum pulse width value in microseconds
    @param max the maximum pulse width value in microseconds
    @returns 0
*/
/**************************************************************************/
uint8_t seesaw_Servo::attach(int pin, int min, int max) {
  attach(pin);
  this->min = min * 3.2767;
  this->max = max * 3.2767;

  return 0;
}

/**************************************************************************/
/*!
    @brief  write a value. if value is < 200 its treated as an angle, otherwise
   as pulse width in microseconds
    @param  value the value to write
*/
/**************************************************************************/
void seesaw_Servo::write(int value) {
  if (value < 200) {
    // angle
    uint16_t val = map(value, 0, 180, min, max);
    val = constrain(val, min, max);
    _ss->analogWrite(_pin, val);
    _sval = val;
  } else
    writeMicroseconds(value);
}

/**************************************************************************/
/*!
    @brief  get current value
    @returns  current pulse width as an angle between 0 and 180 degrees
*/
/**************************************************************************/
int seesaw_Servo::read() { return map(_sval, MIN_PULSE, MAX_PULSE, 0, 180); }

/**************************************************************************/
/*!
    @brief  Write pulse width in microseconds
    @param  value the value to write
*/
/**************************************************************************/
void seesaw_Servo::writeMicroseconds(int value) {
  uint16_t val = 3.2767 * value;
  _ss->analogWrite(_pin, val);
  _sval = val;
}