qrms.dox

/*! @page qrms_desc  Recursive Root Mean Square estimator
* Real-time digital systems often require the calculation of a root-mean, such
* as a root-mean-square (RMS) level or average magnitude of a complex signal.
* While averaging can be efficiently implemented by most microprocessors,
* obtaining an efficient and rapidly converging algorithm is surely a
* time-consuming task due to the adjustments and optimizations that need to be
* performed. On the other hand, calculating the square root can be challenging,
* especially with low-cost hardware. If the processor does not have a built-in
* fast square root function, it must be implemented in software. While this
* can provide accurate results, it may not be as efficient.
*
* \ref qlibs::rms provides a super-efficient method to compute the Recursive Root
* Mean Square (RMS). The implementation uses 3-stage filtering and Newton's
* method to obtain the square root. The filter parameters are perfectly tuned
* and optimized to converge in around 16 cycles, operating at a sampling rate
* of 1mS. This means that you must configure your embedded system to meet those
* specifications, either by configuring a timer interrupt or by delegating
* responsibility to a real-time task.
*
* @section qrms_ex1 Example: Using a Timer Interrupt
*
* The following example demonstrates how to configure a timer to periodically update the RMS
* estimator at a 1 ms interval.
*
* @b File: @c rms_compute.c
*  @code{.c}
*  #include "bsp.h"
*  #include "hal_timer.h"
*  #include <qlibs.h>
*
*  using namespace qlibs;
*
*  static rms rms_instance;
*  static volatile real_t rms_value = 0.0f;
*  static real_t window[ 8 ] = { 0.0f };
*
*  void TimerA0_Int_Handler( void ) //interrupt tick at 1mS
*  {
*      rms_value = rms_instance.update( get_sample() );
*      HAL_TimerA0_ClearStatusFlag();
*  }
*
*  void rms_setup( void )
*  {
*      rms_instance.setup( window );
*      HAL_TimerA0_Init();
*      HAL_TimerA0_SetPeriod_mS( 1 );
*      HAL_TimerA0_EnableInterrupts();
*      HAL_TimerA0_Enable();
*  }
*
*  float rms_getvalue( void )
*  {
*      return rms_value;
*  }
*
*
*  @endcode
*
*  @b File: @c rms_compute.h
*  @code{.c}
*
*  #ifndef RMS_COMPUTE_H
*  #define RMS_COMPUTE_H
*
*  #ifdef __cplusplus
*  extern "C" {
*  #endif
*
*      void rms_setup( void );
*      float rms_getvalue( void );
*
*  #ifdef __cplusplus
*  }
*  #endif
*
*  #endif
*  @endcode
*/
*/