MicroAPRS/bertos/algo/ramp.h

167 lines
4.3 KiB
C

/**
* \file
* <!--
* Copyright 2004, 2008 Develer S.r.l. (http://www.develer.com/)
* All Rights Reserved.
* -->
*
* \brief Compute, save and load ramps for stepper motors.
*
* The acceleration ramp is used to properly accelerate a stepper motor. The main
* entry point is the function ramp_evaluate(), which must be called at every step
* of the motor: it gets as input the time elapsed since the stepper started
* accelerating, and returns the time to wait before sending the next step. A pseudo
* usage pattern is as follows:
*
* <pre>
* float time = 0;
* while (1)
* {
* float delta = ramp_evaluate(&my_ramp, time);
* sleep(delta);
* do_motor_step();
* time += delta;
* }
* </pre>
*
* A similar pattern can be used to decelerate (it is sufficient to move the total
* time backward, such as "time -= delta").
*
* The ramp can be configured with ramp_setup(), providing it with the minimum and
* maximum operating frequency of the motor, and the total acceleration time in
* milliseconds (that is, the time that will be needed to accelerate from the
* minimum frequency to the maximum frequency).
*
* Both a very precise floating point and a very fast fixed point implementation
* of the ramp evaluation are provided. The fixed point is hand-optimized assembly
* for DSP56000 (but a portable C version of it can be easily written, see the
* comments in the code).
*
*
* \author Simone Zinanni <s.zinanni@develer.com>
* \author Giovanni Bajo <rasky@develer.com>
* \author Daniele Basile <asterix@develer.com>
*
* $WIZ$ module_name = "ramp"
* $WIZ$ module_configuration = "bertos/cfg/cfg_ramp.h"
*/
#ifndef ALGO_RAMP_H
#define ALGO_RAMP_H
#include "hw/hw_stepper.h"
#include "cfg/cfg_ramp.h"
#include <cfg/compiler.h>
/**
* Convert microseconds to timer clock ticks
*/
#define TIME2CLOCKS(micros) ((uint32_t)(micros) * (STEPPER_CLOCK / 1000000))
/**
* Convert timer clock ticks back to microseconds
*/
#define CLOCKS2TIME(clocks) ((uint32_t)(clocks) / (STEPPER_CLOCK / 1000000))
/**
* Convert microseconds to Hz
*/
#define MICROS2FREQ(micros) (1000000UL / ((uint32_t)(micros)))
/**
* Convert frequency (in Hz) to time (in microseconds)
*/
#define FREQ2MICROS(hz) (1000000UL / ((uint32_t)(hz)))
/**
* Multiply \p a and \p b two integer at 32 bit and extract the high 16 bit word.
*/
#define FIX_MULT32(a,b) (((uint64_t)(a)*(uint32_t)(b)) >> 16)
/**
* Structure holding pre-calculated data for speeding up real-time evaluation
* of the ramp. This structure is totally different between the fixed and the
* floating point version of the code.
*
* Consult the file-level documentation of ramp.c for more information about
* the values of this structure.
*/
struct RampPrecalc
{
#if RAMP_USE_FLOATING_POINT
float beta;
float alpha;
float gamma;
#else
uint16_t max_div_min;
uint32_t inv_total_time;
#endif
};
/**
* Ramp structure
*/
struct Ramp
{
uint32_t clocksRamp;
uint16_t clocksMinWL;
uint16_t clocksMaxWL;
struct RampPrecalc precalc; ///< pre-calculated values for speed
};
/*
* Function prototypes
*/
void ramp_compute(
struct Ramp * ramp,
uint32_t clocksInRamp,
uint16_t clocksInMinWavelength,
uint16_t clocksInMaxWavelength);
/** Setup an acceleration ramp for a stepper motor
*
* \param ramp Ramp to fill
* \param length Length of the ramp (milliseconds)
* \param minFreq Minimum operating frequency of the motor (hertz)
* \param maxFreq Maximum operating frequency of the motor (hertz)
*
*/
void ramp_setup(struct Ramp* ramp, uint32_t length, uint32_t minFreq, uint32_t maxFreq);
/**
* Initialize a new ramp with default values
*/
void ramp_default(struct Ramp *ramp);
/**
* Evaluate the ramp at the given point. Given a \a ramp, and the current \a clock since
* the start of the acceleration, compute the next step, that is the interval at which
* send the signal to the motor.
*
* \note The fixed point version does not work when curClock is zero. Anyway,
* the first step is always clocksMaxWL, as stored within the ramp structure.
*/
#if RAMP_USE_FLOATING_POINT
float ramp_evaluate(const struct Ramp* ramp, float curClock);
#else
uint16_t ramp_evaluate(const struct Ramp* ramp, uint32_t curClock);
#endif
/** Self test */
int ramp_testSetup(void);
int ramp_testRun(void);
int ramp_testTearDown(void);
#endif /* ALGO_RAMP_H */