/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file mixer_simple.cpp
*
* Simple summing mixer.
*/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <poll.h>
#include <errno.h>
#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <ctype.h>
#include "mixer.h"
#define debug(fmt, args...) do { } while(0)
//#define debug(fmt, args...) do { printf("[mixer] " fmt "\n", ##args); } while(0)
SimpleMixer::SimpleMixer(ControlCallback control_cb,
uintptr_t cb_handle,
mixer_simple_s *mixinfo) :
Mixer(control_cb, cb_handle),
_info(mixinfo)
{
}
SimpleMixer::~SimpleMixer()
{
if (_info != nullptr)
free(_info);
}
static const char *
findtag(const char *buf, unsigned &buflen, char tag)
{
while (buflen >= 2) {
if ((buf[0] == tag) && (buf[1] == ':'))
return buf;
buf++;
buflen--;
}
return nullptr;
}
static void
skipline(const char *buf, unsigned &buflen)
{
const char *p;
/* if we can find a CR or NL in the buffer, skip up to it */
if ((p = (const char *)memchr(buf, '\r', buflen)) || (p = (const char *)memchr(buf, '\n', buflen)))
buflen -= (p - buf);
}
int
SimpleMixer::parse_output_scaler(const char *buf, unsigned &buflen, mixer_scaler_s &scaler)
{
int ret;
int s[5];
buf = findtag(buf, buflen, 'O');
if ((buf == nullptr) || (buflen < 12))
return -1;
if ((ret = sscanf(buf, "O: %d %d %d %d %d",
&s[0], &s[1], &s[2], &s[3], &s[4])) != 5) {
debug("scaler parse failed on '%s' (got %d)", buf, ret);
return -1;
}
skipline(buf, buflen);
scaler.negative_scale = s[0] / 10000.0f;
scaler.positive_scale = s[1] / 10000.0f;
scaler.offset = s[2] / 10000.0f;
scaler.min_output = s[3] / 10000.0f;
scaler.max_output = s[4] / 10000.0f;
return 0;
}
int
SimpleMixer::parse_control_scaler(const char *buf, unsigned &buflen, mixer_scaler_s &scaler, uint8_t &control_group, uint8_t &control_index)
{
unsigned u[2];
int s[5];
buf = findtag(buf, buflen, 'S');
if ((buf == nullptr) || (buflen < 16))
return -1;
if (sscanf(buf, "S: %u %u %d %d %d %d %d",
&u[0], &u[1], &s[0], &s[1], &s[2], &s[3], &s[4]) != 7) {
debug("control parse failed on '%s'", buf);
return -1;
}
skipline(buf, buflen);
control_group = u[0];
control_index = u[1];
scaler.negative_scale = s[0] / 10000.0f;
scaler.positive_scale = s[1] / 10000.0f;
scaler.offset = s[2] / 10000.0f;
scaler.min_output = s[3] / 10000.0f;
scaler.max_output = s[4] / 10000.0f;
return 0;
}
SimpleMixer *
SimpleMixer::from_text(Mixer::ControlCallback control_cb, uintptr_t cb_handle, const char *buf, unsigned &buflen)
{
SimpleMixer *sm = nullptr;
mixer_simple_s *mixinfo = nullptr;
unsigned inputs;
int used;
const char *end = buf + buflen;
/* get the base info for the mixer */
if (sscanf(buf, "M: %u%n", &inputs, &used) != 1) {
debug("simple parse failed on '%s'", buf);
goto out;
}
buflen -= used;
mixinfo = (mixer_simple_s *)malloc(MIXER_SIMPLE_SIZE(inputs));
if (mixinfo == nullptr) {
debug("could not allocate memory for mixer info");
goto out;
}
mixinfo->control_count = inputs;
if (parse_output_scaler(end - buflen, buflen, mixinfo->output_scaler))
goto out;
for (unsigned i = 0; i < inputs; i++) {
if (parse_control_scaler(end - buflen, buflen,
mixinfo->controls[i].scaler,
mixinfo->controls[i].control_group,
mixinfo->controls[i].control_index))
goto out;
}
sm = new SimpleMixer(control_cb, cb_handle, mixinfo);
if (sm != nullptr) {
mixinfo = nullptr;
debug("loaded mixer with %d inputs", inputs);
} else {
debug("could not allocate memory for mixer");
}
out:
if (mixinfo != nullptr)
free(mixinfo);
return sm;
}
SimpleMixer *
SimpleMixer::pwm_input(Mixer::ControlCallback control_cb, uintptr_t cb_handle, unsigned input, uint16_t min, uint16_t mid, uint16_t max)
{
SimpleMixer *sm = nullptr;
mixer_simple_s *mixinfo = nullptr;
mixinfo = (mixer_simple_s *)malloc(MIXER_SIMPLE_SIZE(1));
if (mixinfo == nullptr) {
debug("could not allocate memory for mixer info");
goto out;
}
mixinfo->control_count = 1;
/*
* Always pull from group 0, with the input value giving the channel.
*/
mixinfo->controls[0].control_group = 0;
mixinfo->controls[0].control_index = input;
/*
* Conversion uses both the input and output side of the mixer.
*
* The input side is used to slide the control value such that the min argument
* results in a value of zero.
*
* The output side is used to apply the scaling for the min/max values so that
* the resulting output is a -1.0 ... 1.0 value for the min...max range.
*/
mixinfo->controls[0].scaler.negative_scale = 1.0f;
mixinfo->controls[0].scaler.positive_scale = 1.0f;
mixinfo->controls[0].scaler.offset = -mid;
mixinfo->controls[0].scaler.min_output = -(mid - min);
mixinfo->controls[0].scaler.max_output = (max - mid);
mixinfo->output_scaler.negative_scale = 500.0f / (mid - min);
mixinfo->output_scaler.positive_scale = 500.0f / (max - mid);
mixinfo->output_scaler.offset = 0.0f;
mixinfo->output_scaler.min_output = -1.0f;
mixinfo->output_scaler.max_output = 1.0f;
sm = new SimpleMixer(control_cb, cb_handle, mixinfo);
if (sm != nullptr) {
mixinfo = nullptr;
debug("PWM input mixer for %d", input);
} else {
debug("could not allocate memory for PWM input mixer");
}
out:
if (mixinfo != nullptr)
free(mixinfo);
return sm;
}
unsigned
SimpleMixer::mix(float *outputs, unsigned space)
{
float sum = 0.0f;
if (_info == nullptr)
return 0;
if (space < 1)
return 0;
for (unsigned i = 0; i < _info->control_count; i++) {
float input;
_control_cb(_cb_handle,
_info->controls[i].control_group,
_info->controls[i].control_index,
input);
sum += scale(_info->controls[i].scaler, input);
}
*outputs = scale(_info->output_scaler, sum);
return 1;
}
void
SimpleMixer::groups_required(uint32_t &groups)
{
for (unsigned i = 0; i < _info->control_count; i++)
groups |= 1 << _info->controls[i].control_group;
}
int
SimpleMixer::check()
{
int ret;
float junk;
/* sanity that presumes that a mixer includes a control no more than once */
/* max of 32 groups due to groups_required API */
if (_info->control_count > 32)
return -2;
/* validate the output scaler */
ret = scale_check(_info->output_scaler);
if (ret != 0)
return ret;
/* validate input scalers */
for (unsigned i = 0; i < _info->control_count; i++) {
/* verify that we can fetch the control */
if (_control_cb(_cb_handle,
_info->controls[i].control_group,
_info->controls[i].control_index,
junk) != 0) {
return -3;
}
/* validate the scaler */
ret = scale_check(_info->controls[i].scaler);
if (ret != 0)
return (10 * i + ret);
}
return 0;
}
