From 839bb85440ae6b21ef990fd373008a7a021a9148 Mon Sep 17 00:00:00 2001 From: asterix Date: Thu, 20 Mar 2008 14:39:12 +0000 Subject: [PATCH] Move ramp module to appropriate directory. git-svn-id: https://src.develer.com/svnoss/bertos/trunk@1201 38d2e660-2303-0410-9eaa-f027e97ec537 --- {drv => algo}/ramp.c | 0 algo/ramp.h | 199 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 199 insertions(+) rename {drv => algo}/ramp.c (100%) create mode 100644 algo/ramp.h diff --git a/drv/ramp.c b/algo/ramp.c similarity index 100% rename from drv/ramp.c rename to algo/ramp.c diff --git a/algo/ramp.h b/algo/ramp.h new file mode 100644 index 00000000..f438dc5e --- /dev/null +++ b/algo/ramp.h @@ -0,0 +1,199 @@ + +/** + * \file + * + * + * \brief Compute, save and load ramps for stepper motors (interace) + * + * \version $Id$ + * + * \author Simone Zinanni + * \author Giovanni Bajo + * \author Daniele Basile + * + * 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: + * + * 
+ *  float time = 0;
+ *  while (1)
+ *  {
+ *      float delta = ramp_evaluate(&my_ramp, time);
+ *      sleep(delta);
+ *      do_motor_step();
+ *      time += delta;
+ *  }
+ *
+ * + * 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). + * + */ + +#ifndef ALGO_RAMP_H +#define ALGO_RAMP_H + +#include +#include "hw_stepper.h" + +/** + * Define whether the ramp will use floating point calculation within ramp_evaluate(). + * Otherwise, a less precise fixed point version will be used, which is faster on + * platforms which do no support floating point operations. + * + * \note Floating point operations will be always done within ramp_compute() to + * precalculate values, so there has to be at least a floating point emulation support. + */ +#define RAMP_USE_FLOATING_POINT 0 + + +#if !RAMP_USE_FLOATING_POINT + + /** + * Number of least-significant bits which are stripped away during ramp evaluation. + * This setting allows to specify larger ramps at the price of less precision. + * + * The maximum ramp size allowed is 2^(24 + RAMP_CLOCK_SHIFT_PRECISION), in clocks. + * For instance, using RAMP_CLOCK_SHIFT_PRECISION 1, and a 8x prescaler, the maximum + * length of a ramp is about 6.7 secs. Raising RAMP_CLOCK_SHIFT_PRECISION to 2 + * brings the maximum length to 13.4 secs, at the price of less precision. + * + * ramp_compute() will check that the length is below the maximum allowed through + * a runtime assertion. + * + * \note This macro is used only for the fixed-point version of the ramp. + */ + #define RAMP_CLOCK_SHIFT_PRECISION 2 +#endif + + +///< Negative pulse width for ramp +#define RAMP_PULSE_WIDTH 50 + +///< Default ramp +#define RAMP_DEF_TIME 6000000 ///< microsecs +#define RAMP_DEF_MAXFREQ 5000 ///< Hz +#define RAMP_DEF_MINFREQ 200 ///< Hz +#define RAMP_DEF_POWERRUN 10 ///< 10 deciampere (1 ampere) +#define RAMP_DEF_POWERIDLE 1 ///< 1 deciampere + + +/** + * 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))) + + + +/** + * 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 */ +void ramp_test(void); + +#endif /* ALGO_RAMP_H */ + -- 2.25.1