pimoroni-pico/drivers/servo/servo_state.cpp

#include "servo_state.hpp"

namespace servo {
  ServoState::ServoState(CalibrationType default_type)
    : table(default_type) {
  }

  float ServoState::enable() {
    if(last_enabled_pulse < MIN_VALID_PULSE) {
      servo_value = get_mid_value();
      last_enabled_pulse = table.value_to_pulse(servo_value);
    }
    enabled = true;
    return last_enabled_pulse;
  }

  float ServoState::disable() {
    enabled = false;
    return 0.0f; // A zero pulse
  }

  bool ServoState::is_enabled() const {
    return enabled;
  }

  float ServoState::get_value() const {
    return servo_value;
  }

  float ServoState::set_value(float value) {
    servo_value = value;
    float pulse = table.value_to_pulse(value);
    if(pulse >= MIN_VALID_PULSE) {
      last_enabled_pulse = pulse;
      enabled = true;
    }
    else {
      pulse = disable();
    }
    return pulse;
  }

  float ServoState::get_pulse() const {
    return last_enabled_pulse;
  }

  float ServoState::set_pulse(float pulse) {
    if(pulse >= MIN_VALID_PULSE) {
      servo_value = table.value_from_pulse(pulse);
      last_enabled_pulse = pulse;
      enabled = true;
    }
    else {
      pulse = disable();
    }
    return pulse;
  }

  float ServoState::get_min_value() const {
    float value = 0.0f;
    Calibration::Point *point = table.first_point();
    if(point != nullptr) {
      value = point->value;
    }
    return value;
  }

  float ServoState::get_mid_value() const {
    float value = 0.0f;
    Calibration::Point *first = table.first_point();
    Calibration::Point *last = table.last_point();
    if((first != nullptr) && (last != nullptr)) {
      value = (first->value + last->value) / 2.0f;
    }
    return value;
  }

  float ServoState::get_max_value() const {
    float value = 0.0f;
    Calibration::Point *point = table.last_point();
    if(point != nullptr) {
      value = point->value;
    }
    return value;
  }

  float ServoState::to_min() {
    return set_value(get_min_value());
  }

  float ServoState::to_mid() {
    return set_value(get_mid_value());
  }

  float ServoState::to_max() {
    return set_value(get_max_value());
  }

  float ServoState::to_percent(float in, float in_min, float in_max) {
    float value = Calibration::map_float(in, in_min, in_max, get_min_value(), get_max_value());
    return set_value(value);
  }

  float ServoState::to_percent(float in, float in_min, float in_max, float value_min, float value_max) {
    float value = Calibration::map_float(in, in_min, in_max, value_min, value_max);
    return set_value(value);
  }

  Calibration& ServoState::calibration() {
    return table;
  }

  const Calibration& ServoState::calibration() const {
    return table;
  }

  uint32_t ServoState::pulse_to_level(float pulse, uint32_t resolution) {
    uint32_t level = 0;
    if(pulse >= MIN_VALID_PULSE) {
        // Constrain the level to hardcoded limits to protect the servo
        pulse = MIN(MAX(pulse, LOWER_HARD_LIMIT), UPPER_HARD_LIMIT);
        level = (uint32_t)((pulse * (float)resolution) / SERVO_PERIOD);
    }
    return level;
  }

};