xytronic-lf/firmware/measure_current.c

/*
 * Xytronic LF-1600
 * Current measurement routines
 *
 * Copyright (c) 2015-2017 Michael Buesch <m@bues.ch>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "measure_current.h"
#include "measure.h"
#include "timer.h"
#include "scale.h"
#include "controller_current.h"
#include "filter.h"
#include "debug_uart.h"

#include <string.h>


/* Low pass filter time. */
#define MEASCURR_FILTER_SHIFT		4


struct meascurr_context {
	bool initialized;
	fixpt_t prev_feedback;
	struct lp_filter_u16 filter;
	int16_t old_filter_report_value;
};


static struct meascurr_context meascurr;


void meascurr_filter_reset(void)
{
	lp_filter_u16_reset(&meascurr.filter);
}

uint16_t meascurr_filter_handler(uint16_t raw_adc);

uint16_t meascurr_filter_handler(uint16_t raw_adc)
{
	uint16_t filtered_adc;

	/* Run a simple low pass filter. */
	if (meascurr.initialized) {
		filtered_adc = lp_filter_u16_run(&meascurr.filter, raw_adc,
						 MEASCURR_FILTER_SHIFT);
	} else {
		lp_filter_u16_set(&meascurr.filter, raw_adc);
		filtered_adc = raw_adc;
	}
	filtered_adc = min(filtered_adc, MEASURE_MAX_RESULT);

	debug_report_int16(DEBUG_PFX1("fc"), &meascurr.old_filter_report_value,
			   (int16_t)filtered_adc);

	return filtered_adc;
}

void meascurr_result_handler(fixpt_t measured_phys_value,
			     enum measure_plausibility plaus);

void meascurr_result_handler(fixpt_t measured_phys_value,
			     enum measure_plausibility plaus)
{
	uint8_t emergency_flags;

	/* Set/reset emergency status. */
	emergency_flags = contrcurr_get_emerg();
	if (plaus == MEAS_PLAUSIBLE)
		emergency_flags &= (uint8_t)~CONTRCURR_EMERG_UNPLAUS_FEEDBACK;
	else if (plaus == MEAS_PLAUS_TIMEOUT)
		emergency_flags |= CONTRCURR_EMERG_UNPLAUS_FEEDBACK;
	contrcurr_set_emerg(emergency_flags);

	/* Set the controller feedback. */
	if (plaus == MEAS_PLAUSIBLE) {
		meascurr.prev_feedback = measured_phys_value;
		contrcurr_set_feedback(measured_phys_value);
	} else if (plaus == MEAS_NOT_PLAUSIBLE) {
		/* Just run the controller with the previous feedback. */
		contrcurr_set_feedback(meascurr.prev_feedback);
	}

	meascurr.initialized = true;
}

extern
const struct measure_config __flash meascurr_config;
const struct measure_config __flash meascurr_config = {
	.name			= "mc",
	.mux			= MEAS_MUX_ADC2,
	.did			= MEAS_DID_ADC2,
	.ps			= MEAS_PS_64,
	.ref			= MEAS_REF_AREF,
	.averaging_timeout_ms	= 5,
	.scale_raw_lo		= 0,
	.scale_raw_hi		= 65,
	.scale_phys_lo		= FLOAT_TO_FIXPT(AMPERE(0)),
	.scale_phys_hi		= FLOAT_TO_FIXPT(AMPERE(1.1)),
	.plaus_neglim		= FLOAT_TO_FIXPT(CONTRCURR_NEGLIM),
	.plaus_poslim		= FLOAT_TO_FIXPT(CONTRCURR_POSLIM),
	.plaus_timeout_ms	= 3000,
};

void meascurr_init(void)
{
	meascurr.initialized = false;
}