text: /* Copyright (c) 2015 Nordic Semiconductor. All Rights Reserved.
   *
   * The information contained herein is property of Nordic Semiconductor ASA.
   * Terms and conditions of usage are described in detail in NORDIC
   * SEMICONDUCTOR STANDARD SOFTWARE LICENSE AGREEMENT.
   *
   * Licensees are granted free, non-transferable use of the information. NO
   * WARRANTY of ANY KIND is provided. This heading must NOT be removed from
   * the file.
   *
   */
  
  #include "ant_hrm_simulator.h"
  #include "ant_hrm_utils.h"
  #include "nordic_common.h"
  
  #define ITERATION_ANT_CYCLES HRM_MSG_PERIOD_4Hz                                  ///< period of calculation [1/32678 s], defined in ANT device profile
  #define ITERATION_PERIOD     (ITERATION_ANT_CYCLES * 1024 / ANT_CLOCK_FREQUENCY) ///< integer part of calculation's period [1/1024 s]
  #define ITERATION_FRACTION   (ITERATION_ANT_CYCLES * 1024 % ANT_CLOCK_FREQUENCY) ///< fractional part of calculation's period [1/32678 s]
  
  void ant_hrm_simulator_init(ant_hrm_simulator_t           * p_simulator,
                              ant_hrm_simulator_cfg_t const * p_config,
                              bool                            auto_change)
  {
  
      p_simulator->p_profile                          = p_config->p_profile;
      p_simulator->_cb.sensorsim_cfg                  = p_config->sensorsim_cfg;
      p_simulator->_cb.auto_change                    = auto_change;
      p_simulator->_cb.sensorsim_state.current_val    = p_simulator->_cb.sensorsim_cfg.min;
      p_simulator->_cb.time_since_last_hb             = 0;
      p_simulator->_cb.fraction_since_last_hb         = 0;
  
      sensorsim_init(&(p_simulator->_cb.sensorsim_state), &(p_simulator->_cb.sensorsim_cfg));
  }
  
  
  void ant_hrm_simulator_one_iteration(ant_hrm_simulator_t * p_simulator)
  {
  
      if (p_simulator->_cb.auto_change)
      {
          UNUSED_PARAMETER(sensorsim_measure(&(p_simulator->_cb.sensorsim_state),
                                             &(p_simulator->_cb.sensorsim_cfg)));
      }
  
      // @note: Take a local copy within scope in order to assist the compiler in variable register
      // allocation.
      const uint32_t computed_heart_rate_value = p_simulator->_cb.sensorsim_state.current_val;
  
      // @note: This implementation assumes that the current instantaneous heart can vary and this
      // function is called with static frequency.
      // value and the heart rate pulse interval is derived from it. The computation is based on 60
      // seconds in a minute and the used time base is 1/1024 seconds.
      const uint32_t current_hb_pulse_interval = (60u * 1024u) / computed_heart_rate_value;
  
      // update time from last hb detected
      p_simulator->_cb.time_since_last_hb += ITERATION_PERIOD;
  
      // extended celculadion by fraction make calculating accurat in long time perspective
      p_simulator->_cb.fraction_since_last_hb += ITERATION_FRACTION;
      uint32_t add_period = p_simulator->_cb.fraction_since_last_hb / ANT_CLOCK_FREQUENCY;
  
      if (add_period > 0)
      {
          p_simulator->_cb.time_since_last_hb++;
          p_simulator->_cb.fraction_since_last_hb %= ANT_CLOCK_FREQUENCY;
      }
  
      // calc number of hb as will fill
      uint32_t new_beats      = p_simulator->_cb.time_since_last_hb / current_hb_pulse_interval;
      uint32_t add_event_time = new_beats * current_hb_pulse_interval;
  
      if (new_beats > 0)
      {
          p_simulator->p_profile->HRM_PROFILE_computed_heart_rate =
              (uint8_t)computed_heart_rate_value;
  
          // Current heart beat event time is the previous event time added with the current heart rate
          // pulse interval.
          uint32_t current_heart_beat_event_time = p_simulator->p_profile->HRM_PROFILE_beat_time +
                                                   add_event_time;
  
          // Set current event time.
          p_simulator->p_profile->HRM_PROFILE_beat_time = current_heart_beat_event_time; // <- B<4,5> <-
  
          // Set previous event time. // p4.B<2,3> <- B<4,5>
          p_simulator->p_profile->HRM_PROFILE_prev_beat =
              p_simulator->p_profile->HRM_PROFILE_beat_time - current_hb_pulse_interval;
  
          // Event count.
          p_simulator->p_profile->HRM_PROFILE_beat_count += new_beats; // B<6>
  
          p_simulator->_cb.time_since_last_hb -= add_event_time;
      }
  }
  
  
  void ant_hrm_simulator_increment(ant_hrm_simulator_t * p_simulator)
  {
      if (!p_simulator->_cb.auto_change)
      {
          sensorsim_increment(&(p_simulator->_cb.sensorsim_state),
                              &(p_simulator->_cb.sensorsim_cfg));
      }
  }
  
  
  void ant_hrm_simulator_decrement(ant_hrm_simulator_t * p_simulator)
  {
      if (!p_simulator->_cb.auto_change)
      {
          sensorsim_decrement(&(p_simulator->_cb.sensorsim_state),
                              &(p_simulator->_cb.sensorsim_cfg));
      }
  }
  
  
  