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-rw-r--r--ROMFS/mixers/FMU_AET.mix2
-rw-r--r--ROMFS/mixers/FMU_RET.mix2
-rw-r--r--ROMFS/mixers/FMU_delta.mix2
-rw-r--r--ROMFS/mixers/FMU_multirotor.mix24
-rw-r--r--apps/drivers/drv_mixer.h110
-rw-r--r--apps/px4/fmu/fmu.cpp161
-rw-r--r--apps/systemcmds/mixer/mixer.c261
-rw-r--r--apps/systemlib/Makefile1
-rw-r--r--apps/systemlib/mixer.c345
-rw-r--r--apps/systemlib/mixer.h236
-rw-r--r--apps/systemlib/mixer/Makefile39
-rw-r--r--apps/systemlib/mixer/mixer.cpp211
-rw-r--r--apps/systemlib/mixer/mixer.h358
-rw-r--r--apps/systemlib/mixer/mixer_group.cpp288
-rw-r--r--apps/systemlib/mixer/mixer_multirotor.cpp81
-rw-r--r--nuttx/configs/px4fmu/nsh/appconfig1
16 files changed, 1165 insertions, 957 deletions
diff --git a/ROMFS/mixers/FMU_AET.mix b/ROMFS/mixers/FMU_AET.mix
index 9ae23f264..1f1931861 100644
--- a/ROMFS/mixers/FMU_AET.mix
+++ b/ROMFS/mixers/FMU_AET.mix
@@ -46,7 +46,7 @@ Output 2
--------
This mixer is empty.
-M: 0
+Z:
Motor speed mixer
-----------------
diff --git a/ROMFS/mixers/FMU_RET.mix b/ROMFS/mixers/FMU_RET.mix
index 94815b48e..b2fff7224 100644
--- a/ROMFS/mixers/FMU_RET.mix
+++ b/ROMFS/mixers/FMU_RET.mix
@@ -39,7 +39,7 @@ Output 2
--------
This mixer is empty.
-M: 0
+Z:
Motor speed mixer
-----------------
diff --git a/ROMFS/mixers/FMU_delta.mix b/ROMFS/mixers/FMU_delta.mix
index 7b878e40b..b01284ef7 100644
--- a/ROMFS/mixers/FMU_delta.mix
+++ b/ROMFS/mixers/FMU_delta.mix
@@ -35,7 +35,7 @@ Output 2
--------
This mixer is empty.
-M: 0
+Z:
Motor speed mixer
-----------------
diff --git a/ROMFS/mixers/FMU_multirotor.mix b/ROMFS/mixers/FMU_multirotor.mix
new file mode 100644
index 000000000..6175b18e1
--- /dev/null
+++ b/ROMFS/mixers/FMU_multirotor.mix
@@ -0,0 +1,24 @@
+Multirotor mixer for PX4FMU
+===========================
+
+This file defines passthrough mixers suitable for driving ESCs over the full
+input range.
+
+Channel group 0, channels 0-3 values 0.0 - 1.0 are scaled to the full output range.
+
+M: 2
+S: 0 0 10000 10000 0 -10000 10000
+S: 0 0 0 20000 -10000 -10000 10000
+
+M: 2
+S: 0 0 10000 10000 0 -10000 10000
+S: 0 1 0 20000 -10000 -10000 10000
+
+M: 2
+S: 0 0 10000 10000 0 -10000 10000
+S: 0 2 0 20000 -10000 -10000 10000
+
+M: 2
+S: 0 0 10000 10000 0 -10000 10000
+S: 0 3 0 20000 -10000 -10000 10000
+
diff --git a/apps/drivers/drv_mixer.h b/apps/drivers/drv_mixer.h
index d66fbf3a9..daa79c265 100644
--- a/apps/drivers/drv_mixer.h
+++ b/apps/drivers/drv_mixer.h
@@ -34,10 +34,20 @@
/**
* @file drv_mixer.h
*
- * Mixer ioctl interface.
+ * Mixer ioctl interfaces.
*
- * This interface can/should be exported by any device that supports
- * control -> actuator mixing.
+ * Normal workflow is:
+ *
+ * - open mixer device
+ * - add mixer(s)
+ * loop:
+ * - mix actuators to array
+ *
+ * Each client has its own configuration.
+ *
+ * When mixing, outputs are produced by mixers in the order they are
+ * added. A simple mixer produces one output; a multotor mixer will
+ * produce several outputs, etc.
*/
#ifndef _DRV_MIXER_H
@@ -46,51 +56,83 @@
#include <stdint.h>
#include <sys/ioctl.h>
-#include <systemlib/mixer.h>
+#define MIXER_DEVICE_PATH "/dev/mixer"
-/**
- * Structure used for receiving mixers.
- *
- * Note that the mixers array is not actually an array of mixers; it
- * simply represents the first mixer in the buffer.
+/*
+ * ioctl() definitions
*/
-struct MixInfo {
- unsigned num_controls;
- struct mixer_s mixer;
+#define _MIXERIOCBASE (0x2400)
+#define _MIXERIOC(_n) (_IOC(_MIXERIOCBASE, _n))
+
+/** get the number of mixable outputs */
+#define MIXERIOCGETOUTPUTCOUNT _MIXERIOC(0)
+
+/** reset (clear) the mixer configuration */
+#define MIXERIOCRESET _MIXERIOC(1)
+
+/** simple channel scaler */
+struct mixer_scaler_s
+{
+ float negative_scale;
+ float positive_scale;
+ float offset;
+ float min_output;
+ float max_output;
};
-/**
- * Handy macro for determining the allocation size of a MixInfo structure.
- */
-#define MIXINFO_SIZE(_num_controls) (sizeof(struct MixInfo) + ((_num_controls) * sizeof(struct scaler_s)))
+/** mixer input */
+struct mixer_input_s
+{
+ uint8_t control_group; /**< group from which the input reads */
+ uint8_t control_index; /**< index within the control group */
+ struct mixer_scaler_s scaler; /**< scaling applied to the input before use */
+};
-/*
- * ioctl() definitions
+/** simple mixer */
+struct mixer_simple_s
+{
+ uint8_t input_count; /**< number of inputs */
+ struct mixer_scaler_s output_scaler; /**< scaling for the output */
+ struct mixer_input_s inputs[0]; /**< actual size of the array is set by input_count */
+};
+
+#define MIXER_SIMPLE_SIZE(_icount) (sizeof(struct mixer_simple_s) + (_icount) * sizeof(struct mixer_input_s))
+
+/**
+ * add a simple mixer in (struct mixer_simple_s *)arg
*/
+#define MIXERIOCADDSIMPLE _MIXERIOC(2)
-#define _MIXERIOCBASE (0x2400)
-#define _MIXERIOC(_n) (_IOC(_MIXERIOCBASE, _n))
+/** multirotor output definition */
+struct mixer_rotor_output_s
+{
+ float angle; /**< rotor angle clockwise from forward in radians */
+ float distance; /**< motor distance from centre in arbitrary units */
+};
-/** get the number of actuators that require mixers in *(unsigned)arg */
-#define MIXERIOCGETMIXERCOUNT _MIXERIOC(0)
+/** multirotor mixer */
+struct mixer_multirotor_s
+{
+ uint8_t rotor_count;
+ struct mixer_input_s inputs[4]; /**< inputs are roll, pitch, yaw, thrust */
+ struct mixer_rotor_output_s rotors[0]; /**< actual size of the array is set by rotor_count */
+};
/**
- * Copy a mixer from the device into *(struct MixInfo *)arg.
- *
- * The num_controls field indicates the number of controls for which space
- * is allocated following the MixInfo structure. If the allocation
- * is too small, no mixer data is retured. The control_count field in
- * the MixInfo.mixer structure is always updated.
- *
- * If no mixer is assigned for the given index, the ioctl returns ENOENT.
+ * Add a multirotor mixer in (struct mixer_multirotor_s *)arg
*/
-#define MIXERIOCGETMIXER(_mixer) _MIXERIOC(0x20 + _mixer)
+#define MIXERIOCADDMULTIROTOR _MIXERIOC(3)
/**
- * Copy a mixer from *(struct mixer_s *)arg to the device.
+ * Add mixers(s) from a the file in (const char *)arg
+ */
+#define MIXERIOCLOADFILE _MIXERIOC(4)
+
+/*
+ * XXX Thoughts for additional operations:
*
- * If arg is zero, the mixer is deleted.
+ * - get/set output scale, for tuning center/limit values.
+ * - save/serialise for saving tuned mixers.
*/
-#define MIXERIOCSETMIXER(_mixer) _MIXERIOC(0x40 + _mixer)
#endif /* _DRV_ACCEL_H */
diff --git a/apps/px4/fmu/fmu.cpp b/apps/px4/fmu/fmu.cpp
index 3021321da..779df4ba1 100644
--- a/apps/px4/fmu/fmu.cpp
+++ b/apps/px4/fmu/fmu.cpp
@@ -57,12 +57,14 @@
#include <drivers/device/device.h>
#include <drivers/drv_pwm_output.h>
#include <drivers/drv_gpio.h>
+
+#include <systemlib/mixer/mixer.h>
#include <drivers/drv_mixer.h>
+#include <arch/board/up_pwm_servo.h>
+
#include <uORB/topics/actuator_controls.h>
-#include <systemlib/mixer.h>
-#include <arch/board/up_pwm_servo.h>
class FMUServo : public device::CDev
{
@@ -91,10 +93,20 @@ private:
volatile bool _task_should_exit;
bool _armed;
- mixer_s *_mixer[_max_actuators];
+ MixerGroup *_mixers;
+
+ actuator_controls_s _controls;
static void task_main_trampoline(int argc, char *argv[]);
void task_main();
+
+ static int control_callback_trampoline(uintptr_t handle,
+ uint8_t control_group,
+ uint8_t control_index,
+ float &input);
+ int control_callback(uint8_t control_group,
+ uint8_t control_index,
+ float &input);
};
namespace
@@ -111,10 +123,9 @@ FMUServo::FMUServo(Mode mode) :
_t_actuators(-1),
_t_armed(-1),
_task_should_exit(false),
- _armed(false)
+ _armed(false),
+ _mixers(nullptr)
{
- for (unsigned i = 0; i < _max_actuators; i++)
- _mixer[i] = nullptr;
}
FMUServo::~FMUServo()
@@ -226,23 +237,19 @@ FMUServo::task_main()
/* do we have a control update? */
if (fds[0].revents & POLLIN) {
- struct actuator_controls_s ac;
- float *controls[1] = { &ac.control[0] };
+ float outputs[num_outputs];
/* get controls */
- orb_copy(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, _t_actuators, &ac);
+ orb_copy(ORB_ID_VEHICLE_ATTITUDE_CONTROLS, _t_actuators, &_controls);
+
+ /* do mixing */
+ _mixers->mix(&outputs[0], num_outputs);
/* iterate actuators */
for (unsigned i = 0; i < num_outputs; i++) {
- /* if the actuator is configured */
- if (_mixer[i] != nullptr) {
- /* mix controls to the actuator */
- float output = mixer_mix(_mixer[i], &controls[0]);
-
- /* scale for PWM output 900 - 2100us */
- up_pwm_servo_set(i, 1500 + (600 * output));
- }
+ /* scale for PWM output 900 - 2100us */
+ up_pwm_servo_set(i, 1500 + (600 * outputs[i]));
}
}
@@ -274,12 +281,32 @@ FMUServo::task_main()
}
int
+FMUServo::control_callback_trampoline(uintptr_t handle,
+ uint8_t control_group,
+ uint8_t control_index,
+ float &input)
+{
+ return ((FMUServo *)handle)->control_callback(control_group, control_index, input);
+}
+
+int
+FMUServo::control_callback(uint8_t control_group,
+ uint8_t control_index,
+ float &input)
+{
+ /* XXX currently only supporting group zero */
+ if ((control_group != 0) || (control_index > NUM_ACTUATOR_CONTROLS))
+ return -1;
+
+ input = _controls.control[control_index];
+ return 0;
+}
+
+int
FMUServo::ioctl(struct file *filp, int cmd, unsigned long arg)
{
int ret = OK;
int channel;
- struct MixInfo *mi;
- struct mixer_s *mm, *tmm;
switch (cmd) {
case PWM_SERVO_ARM:
@@ -325,89 +352,57 @@ FMUServo::ioctl(struct file *filp, int cmd, unsigned long arg)
break;
}
- case MIXERIOCGETMIXERCOUNT:
+ case MIXERIOCGETOUTPUTCOUNT:
if (_mode == MODE_4PWM) {
*(unsigned *)arg = 4;
} else {
*(unsigned *)arg = 2;
}
-
break;
- case MIXERIOCGETMIXER(3):
- case MIXERIOCGETMIXER(2):
- if (_mode != MODE_4PWM) {
- ret = -EINVAL;
- break;
- }
-
- /* FALLTHROUGH */
- case MIXERIOCGETMIXER(1):
- case MIXERIOCGETMIXER(0):
- channel = cmd - MIXERIOCGETMIXER(0);
-
- /* if no mixer is assigned, we return ENOENT */
- if (_mixer[channel] == nullptr) {
- ret = -ENOENT;
- break;
+ case MIXERIOCRESET:
+ if (_mixers != nullptr) {
+ delete _mixers;
+ _mixers = nullptr;
}
+ break;
- /* caller's MixInfo */
- mi = (struct MixInfo *)arg;
-
- /* if MixInfo claims to be big enough, copy mixer info */
- if (mi->num_controls >= _mixer[channel]->control_count) {
- memcpy(&mi->mixer, _mixer[channel], MIXER_SIZE(_mixer[channel]->control_count));
+ case MIXERIOCADDSIMPLE: {
+ mixer_simple_s *mixinfo = (mixer_simple_s *)arg;
+ SimpleMixer *mixer = new SimpleMixer(control_callback_trampoline, (uintptr_t)this, mixinfo);
+ if (mixer->check()) {
+ delete mixer;
+ ret = -EINVAL;
} else {
- /* just update MixInfo with actual size of the mixer */
- mi->mixer.control_count = _mixer[channel]->control_count;
+ if (_mixers == nullptr)
+ _mixers = new MixerGroup(control_callback_trampoline, (uintptr_t)this);
+ _mixers->add_mixer(mixer);
}
-
break;
+ }
- case MIXERIOCSETMIXER(3):
- case MIXERIOCSETMIXER(2):
- if (_mode != MODE_4PWM) {
- ret = -EINVAL;
- break;
- }
-
- /* FALLTHROUGH */
- case MIXERIOCSETMIXER(1):
- case MIXERIOCSETMIXER(0):
- channel = cmd - MIXERIOCSETMIXER(0);
-
- /* get the caller-supplied mixer and check */
- mm = (struct mixer_s *)arg;
-
- /* allocate local storage and copy from the caller*/
- if (mm != nullptr) {
-
- if (mixer_check(mm, 1, NUM_ACTUATOR_CONTROLS)) {
- /* only the attitude group is supported */
- ret = -EINVAL;
- break;
- }
+ case MIXERIOCADDMULTIROTOR:
+ /* XXX not yet supported */
+ ret = -ENOTTY;
+ break;
- /* allocate a new mixer struct */
- tmm = (struct mixer_s *)malloc(MIXER_SIZE(mm->control_count));
- memcpy(tmm, mm, MIXER_SIZE(mm->control_count));
+ case MIXERIOCLOADFILE: {
+ const char *path = (const char *)arg;
- } else {
- tmm = nullptr;
+ if (_mixers != nullptr) {
+ delete _mixers;
+ _mixers = nullptr;
+ }
+ _mixers = new MixerGroup(control_callback_trampoline, (uintptr_t)this);
+ if (_mixers->load_from_file(path) != 0) {
+ delete _mixers;
+ _mixers = nullptr;
+ ret = -EINVAL;
}
-
- /* swap in new mixer for old */
- mm = _mixer[channel];
- _mixer[channel] = tmm;
-
- /* if there was an old mixer, free it */
- if (mm != nullptr)
- free(mm);
-
break;
+ }
default:
ret = -ENOTTY;
diff --git a/apps/systemcmds/mixer/mixer.c b/apps/systemcmds/mixer/mixer.c
index bdf54bc20..9d52557e7 100644
--- a/apps/systemcmds/mixer/mixer.c
+++ b/apps/systemcmds/mixer/mixer.c
@@ -44,7 +44,6 @@
#include <fcntl.h>
#include <errno.h>
-#include <systemlib/mixer.h>
#include <drivers/drv_mixer.h>
#include <uORB/topics/actuator_controls.h>
@@ -52,8 +51,6 @@ __EXPORT int mixer_main(int argc, char *argv[]);
static void usage(const char *reason);
static void load(const char *devname, const char *fname);
-static void save(const char *devname, const char *fname);
-static void show(const char *devname);
int
mixer_main(int argc, char *argv[])
@@ -67,18 +64,6 @@ mixer_main(int argc, char *argv[])
load(argv[2], argv[3]);
- } else if (!strcmp(argv[1], "save")) {
- if (argc < 4)
- usage("missing device or filename");
-
- save(argv[2], argv[3]);
-
- } else if (!strcmp(argv[1], "show")) {
- if (argc < 3)
- usage("missing device name");
-
- show(argv[2]);
-
} else {
usage("unrecognised command");
}
@@ -93,146 +78,15 @@ usage(const char *reason)
fprintf(stderr, "%s\n", reason);
fprintf(stderr, "usage:\n");
- fprintf(stderr, " mixer show <device>\n");
- fprintf(stderr, " mixer {load|save} <device> [<filename>]\n");
+ fprintf(stderr, " mixer load <device> <filename>\n");
+ /* XXX automatic setups for quad, etc. */
exit(1);
}
static void
load(const char *devname, const char *fname)
{
- int defs = -1;
- int dev = -1;
- unsigned num_mixers = 0;
- int ret, result = 1;
- struct mixer_s *mixer = NULL;
-
- /* open the device */
- if ((dev = open(devname, 0)) < 0) {
- fprintf(stderr, "can't open %s\n", devname);
- goto out;
- }
-
- /* open the definition file */
- if ((defs = open(fname, O_RDONLY)) < 0) {
- fprintf(stderr, "can't open %s\n", fname);
- goto out;
- }
-
- /* find out how many mixers the device supports */
- ioctl(dev, MIXERIOCGETMIXERCOUNT, (unsigned long)&num_mixers);
-
- if (num_mixers < 1) {
- fprintf(stderr, "can't get mixer count from %s\n", devname);
- goto out;
- }
-
- /* send mixers to the device */
- for (unsigned i = 0; i < num_mixers; i++) {
- ret = mixer_load(defs, &mixer);
-
- if (ret < 0) {
- fprintf(stderr, "read for mixer %d failed\n", i);
- goto out;
- }
-
- /* end of file? */
- if (ret == 0)
- break;
-
- if (mixer != NULL) {
- /* sanity check the mixer */
- ret = mixer_check(mixer, NUM_ACTUATOR_CONTROL_GROUPS, NUM_ACTUATOR_CONTROLS);
-
- if (ret != 0) {
- fprintf(stderr, "mixer %u fails sanity check %d\n", i, ret);
- goto out;
- }
-
- /* send the mixer to the device */
- ret = ioctl(dev, MIXERIOCSETMIXER(i), (unsigned long)mixer);
-
- if (ret < 0) {
- fprintf(stderr, "mixer %d set failed\n", i);
- goto out;
- }
-
- free(mixer);
- mixer = NULL;
-
- } else {
- /* delete the mixer */
- ret = ioctl(dev, MIXERIOCSETMIXER(i), 0);
-
- if (ret < 0) {
- fprintf(stderr, "mixer %d clear failed\n", i);
- goto out;
- }
- }
- }
-
- result = 0;
-
-out:
-
- /* free the mixers array */
- if (mixer != NULL)
- free(mixer);
-
- if (defs != -1)
- close(defs);
-
- if (dev != -1)
- close(dev);
-
- exit(result);
-}
-
-static int
-getmixer(int dev, unsigned mixer_number, struct MixInfo **mip)
-{
- struct MixInfo *mi = *mip;
- int ret;
-
- /* first-round initialisation */
- if (mi == NULL) {
- mi = (struct MixInfo *)malloc(MIXINFO_SIZE(0));
- mi->num_controls = 0;
- }
-
- /* loop trying to get the next mixer until the buffer is big enough */
- do {
- /* try to get the mixer into the buffer as it stands */
- ret = ioctl(dev, MIXERIOCGETMIXER(mixer_number), (unsigned long)mi);
-
- if (ret < 0)
- return -1;
-
- /* did the mixer fit? */
- if (mi->mixer.control_count <= mi->num_controls)
- break;
-
- /* re-allocate to suit */
- mi->num_controls = mi->mixer.control_count;
- mi = (struct MixInfo *)realloc(mi, MIXINFO_SIZE(mi->num_controls));
-
- /* oops, blew up the heap */
- if (mi == NULL)
- return -1;
-
- } while (true);
-
- *mip = mi;
- return 0;
-}
-
-static void
-save(const char *devname, const char *fname)
-{
- struct MixInfo *mi = NULL;
- int defs = -1;
int dev = -1;
- unsigned num_mixers = 0;
int ret, result = 1;
/* open the device */
@@ -241,120 +95,17 @@ save(const char *devname, const char *fname)
goto out;
}
- /* find out how many mixers the device supports */
- ioctl(dev, MIXERIOCGETMIXERCOUNT, (unsigned long)&num_mixers);
-
- if (num_mixers < 1) {
- fprintf(stderr, "can't get mixer count from %s\n", devname);
- goto out;
- }
-
- /* open the definition file */
- if ((defs = open(fname, O_WRONLY | O_CREAT)) < 0) {
- fprintf(stderr, "can't open %s\n", fname);
- goto out;
- }
-
- /* get mixers from the device and save them */
- for (unsigned i = 0; i < num_mixers; i++) {
- struct mixer_s *mm;
-
- ret = getmixer(dev, i, &mi);
- mm = &mi->mixer;
-
- if (ret < 0) {
- if (errno != ENOENT)
- goto out;
-
- mm = NULL;
- }
-
- ret = mixer_save(defs, mm);
-
- if (ret < 0)
- goto out;
+ /* tell it to load the file */
+ ret = ioctl(dev, MIXERIOCLOADFILE, (unsigned long)fname);
+ if (ret != 0) {
+ fprintf(stderr, "failed loading %s\n", fname);
}
result = 0;
-
out:
- /* free the mixinfo */
- if (mi != NULL)
- free(mi);
-
- if (defs != -1)
- close(defs);
-
if (dev != -1)
close(dev);
exit(result);
}
-
-static void
-show(const char *devname)
-{
- struct MixInfo *mi = NULL;
- int dev = -1;
- unsigned num_mixers = 0;
- int ret;
-
- /* open the device */
- if ((dev = open(devname, 0)) < 0) {
- fprintf(stderr, "can't open %s\n", devname);
- goto out;
- }
-
- /* find out how many mixers the device supports */
- ioctl(dev, MIXERIOCGETMIXERCOUNT, (unsigned long)&num_mixers);
-
- if (num_mixers < 1) {
- fprintf(stderr, "can't get mixer count from %s\n", devname);
- goto out;
- }
-
- /* get mixers from the device and print them */
- for (unsigned i = 0; i < num_mixers; i++) {
-
- ret = getmixer(dev, i, &mi);
-
- if (ret < 0) {
- if (errno != ENOENT)
- goto out;
-
- continue;
- }
-
- printf("mixer %d:\n", i);
- printf(" -ve scale +ve scale offset low limit high limit\n");
- printf("output %8.4f %8.4f %8.4f %8.4f %8.4f\n",
- mi->mixer.output_scaler.negative_scale,
- mi->mixer.output_scaler.positive_scale,
- mi->mixer.output_scaler.offset,
- mi->mixer.output_scaler.lower_limit,
- mi->mixer.output_scaler.upper_limit);
-
- for (unsigned j = 0; j < mi->mixer.control_count; j++) {
- printf("(%u,%u) %8.4f %8.4f %8.4f %8.4f %8.4f\n",
- mi->mixer.control_scaler[j].control_group,
- mi->mixer.control_scaler[j].control_index,
- mi->mixer.control_scaler[j].negative_scale,
- mi->mixer.control_scaler[j].positive_scale,
- mi->mixer.control_scaler[j].offset,
- mi->mixer.control_scaler[j].lower_limit,
- mi->mixer.control_scaler[j].upper_limit);
- }
- }
-
-out:
-
- /* free the mixinfo */
- if (mi != NULL)
- free(mi);
-
- if (dev != -1)
- close(dev);
-
- exit(0);
-}
diff --git a/apps/systemlib/Makefile b/apps/systemlib/Makefile
index cb126825d..13cf8271e 100644
--- a/apps/systemlib/Makefile
+++ b/apps/systemlib/Makefile
@@ -36,7 +36,6 @@
#
CSRCS = hx_stream.c \
- mixer.c \
perf_counter.c
#
diff --git a/apps/systemlib/mixer.c b/apps/systemlib/mixer.c
deleted file mode 100644
index b068d3958..000000000
--- a/apps/systemlib/mixer.c
+++ /dev/null
@@ -1,345 +0,0 @@
-/****************************************************************************
- *
- * 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,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- ****************************************************************************/
-
-/**
- * @file mixer.c
- *
- * Generic control value mixing library.
- *
- * This library implements a generic mixer function that can be used
- * by any driver or subsytem that wants to combine several control signals
- * into a single output.
- *
- * See mixer.h for more details.
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
-
-#include "mixer.h"
-
-static int
-scale_check(struct scaler_s *scale)
-{
- if (scale->offset > 1.1f)
- return 1;
-
- if (scale->offset < -1.1f)
- return 2;
-
- if (scale->lower_limit > scale->upper_limit)
- return 3;
-
- if (scale->lower_limit < -1.1f)
- return 4;
-
- if (scale->upper_limit > 1.1f)
- return 5;
-
- return 0;
-}
-
-int
-mixer_check(struct mixer_s *mixer, unsigned group_count, unsigned control_count)
-{
- int ret;
-
- /* sanity that presumes that a mixer includes a control no more than once */
- if (mixer->control_count > (group_count * control_count))
- return -2;
-
- /* validate the output scaler */
- ret = scale_check(&mixer->output_scaler);
-
- if (ret != 0)
- return ret;
-
- /* validate input scalers */
- for (unsigned i = 0; i < mixer->control_count; i++) {
-
- /* range-check input controls */
- if (mixer->control_scaler[i].control_group >= group_count)
- return -3;
-
- if (mixer->control_scaler[i].control_index >= control_count)
- return -3;
-
- /* validate the scaler */
- ret = scale_check(&mixer->control_scaler[i]);
-
- if (ret != 0)
- return (10 * i + ret);
- }
-
- return 0;
-}
-
-void
-mixer_requires(struct mixer_s *mixer, uint32_t *groups)
-{
- for (unsigned i = 0; i < mixer->control_count; i++)
- *groups |= 1 << mixer->control_scaler[i].control_group;
-}
-
-/**
- * Apply a scaler to a value.
- *
- * @param scaler The applied scaler.
- * @param input The value to scale.
- * @output The scaled value.
- */
-static float
-scale(struct scaler_s *scaler, float input)
-{
- float output;
-
- if (input < 0.0f) {
- output = (input * scaler->negative_scale) + scaler->offset;
-
- } else {
- output = (input * scaler->positive_scale) + scaler->offset;
- }
-
- if (output > scaler->upper_limit) {
- output = scaler->upper_limit;
-
- } else if (output < scaler->lower_limit) {
- output = scaler->lower_limit;
- }
-
- return output;
-}
-
-float
-mixer_mix(struct mixer_s *mixer, float **controls)
-{
- float sum = 0.0f;
-
- for (unsigned i = 0; i < mixer->control_count; i++) {
-
- struct scaler_s *scaler = &mixer->control_scaler[i];
- float *cg = controls[scaler->control_group];
-
- sum += scale(scaler, cg[scaler->control_index]);
- }
-
- return scale(&mixer->output_scaler, sum);
-}
-
-/**
- * Effectively fdgets()
- */
-static int
-mixer_getline(int fd, char *line, unsigned maxlen)
-{
- /* reduce line budget by 1 to account for terminal NUL */
- maxlen--;
-
- /* loop looking for a non-comment line */
- for (;;) {
- int ret;
- char c;
- char *p = line;
-
- /* loop reading characters for this line */
- for (;;) {
- ret = read(fd, &c, 1);
-
- /* on error or EOF, return same */
- if (ret <= 0)
- return ret;
-
- /* ignore carriage returns */
- if (c == '\r')
- continue;
-
- /* line termination */
- if (c == '\n') {
- /* ignore malformed lines */
- if ((p - line) < 4)
- break;
-
- if (line[1] != ':')
- break;
-
- /* terminate line as string and return */
- *p = '\0';
- return 1;
- }
-
- /* if we have space, accumulate the byte and go on */
- if ((p - line) < maxlen)
- *p++ = c;
- }
- }
-}
-
-static int
-mixer_load_scaler(const char *buf, struct scaler_s *scaler)
-{
- unsigned u[2];
- int s[5];
-
- 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)
- return -1;
-
- scaler->control_group = u[0];
- scaler->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->lower_limit = s[3] / 10000.0f;
- scaler->upper_limit = s[4] / 10000.0f;
-
- return 0;
-}
-
-int
-mixer_load(int fd, struct mixer_s **mp)
-{
- int ret, result = -1;
- struct mixer_s *mixer = NULL;
- char buf[60];
- unsigned scalers;
-
- ret = mixer_getline(fd, buf, sizeof(buf));
-
- /* end of file? */
- if (ret == 0)
- result = 0;
-
- /* can't proceed */
- if (ret < 1)
- goto out;
-
- /* get header */
- if (sscanf(buf, "M: %u", &scalers) != 1)
- goto out;
-
- /* if there are scalers, load them */
- if (scalers > 0) {
-
- /* allocate mixer */
- scalers--;
- mixer = (struct mixer_s *)malloc(MIXER_SIZE(scalers));
-
- if (mixer == NULL)
- goto out;
-
- mixer->control_count = scalers;
-
- ret = mixer_getline(fd, buf, sizeof(buf));
-
- if (ret < 1)
- goto out;
-
- if (mixer_load_scaler(buf, &mixer->output_scaler))
- goto out;
-
- for (unsigned i = 0; i < scalers; i++) {
- ret = mixer_getline(fd, buf, sizeof(buf));
-
- if (ret < 1)
- goto out;
-
- if (mixer_load_scaler(buf, &mixer->control_scaler[i]))
- goto out;
- }
-
- } else {
- /* we return NULL for the mixer, which is interpreted elsewhere as "no mixer" */
- }
-
- result = 1;
-
-out:
-
- /* on error, discard allocated mixer */
- if ((result <= 0) && (mixer != NULL))
- free(mixer);
-
- *mp = mixer;
- return result;
-}
-
-static int
-mixer_save_scaler(char *buf, struct scaler_s *scaler)
-{
- int s[5];
-
- s[0] = 10000.0f * scaler->negative_scale;
- s[1] = 10000.0f * scaler->positive_scale;
- s[2] = 10000.0f * scaler->offset;
- s[3] = 10000.0f * scaler->lower_limit;
- s[4] = 10000.0f * scaler->upper_limit;
-
- return sprintf(buf, "S: %u %u %d %d %d %d %d\n",
- scaler->control_group, scaler->control_index,
- s[0], s[1], s[2], s[3], s[4]);
-}
-
-int
-mixer_save(int fd, struct mixer_s *mixer)
-{
- char buf[100];
- int len, ret;
-
- /* write the mixer header */
- len = sprintf(buf, "M: %u\n", (mixer != NULL) ? mixer->control_count : 0);
- ret = write(fd, buf, len);
-
- if (ret != len)
- return -1;
-
- if (mixer != NULL) {
- /* write the output scaler */
- len = mixer_save_scaler(buf, &mixer->output_scaler);
- write(fd, buf, len);
-
- if (ret != len)
- return -1;
-
- /* write the control scalers */
- for (unsigned j = 0; j < mixer->control_count; j++) {
- len = mixer_save_scaler(buf, &mixer->control_scaler[j]);
- write(fd, buf, len);
-
- if (ret != len)
- return -1;
- }
- }
-
- return 0;
-} \ No newline at end of file
diff --git a/apps/systemlib/mixer.h b/apps/systemlib/mixer.h
deleted file mode 100644
index 3a9e31bb1..000000000
--- a/apps/systemlib/mixer.h
+++ /dev/null
@@ -1,236 +0,0 @@
-/****************************************************************************
- *
- * 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,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- *
- ****************************************************************************/
-
-#ifndef _SYSTEMLIB_MIXER_H
-#define _SYSTEMLIB_MIXER_H
-
-/**
- * @file mixer.h
- *
- * Generic control value mixing library.
- *
- * This library implements a generic mixer function that can be used
- * by any driver or subsytem that wants to combine several control signals
- * into a single output.
- *
- * Terminology
- * ===========
- *
- * control value
- * A mixer input value, typically provided by some controlling
- * component of the system.
- *
- * control group
- * A collection of controls provided by a single controlling component.
- *
- * actuator
- * The mixer output value.
- *
- * Mixing basics
- * =============
- *
- * An actuator derives its value from the combination of one or more
- * control values. Each of the control values is scaled according to
- * the actuator's configuration and then combined to produce the
- * actuator value, which may then be further scaled to suit the specific
- * output type.
- *
- * Internally, all scaling is performed using floating point values.
- * Inputs and outputs are clamped to the range -1.0 to 1.0.
- *
- * control control control
- * | | |
- * v v v
- * scale scale scale
- * | | |
- * | v |
- * +-------> mix <------+
- * |
- * scale
- * |
- * v
- * out
- *
- * Scaling
- * -------
- *
- * Each scaler allows the input value to be scaled independently for
- * inputs greater/less than zero. An offset can be applied to the output,
- * as well as lower and upper boundary constraints.
- * Negative scaling factors cause the output to be inverted (negative input
- * produces positive output).
- *
- * Scaler pseudocode:
- *
- * if (input < 0)
- * output = (input * NEGATIVE_SCALE) + OFFSET
- * else
- * output = (input * POSITIVE_SCALE) + OFFSET
- *
- * if (output < LOWER_LIMIT)
- * output = LOWER_LIMIT
- * if (output > UPPER_LIMIT)
- * output = UPPER_LIMIT
- *
- *
- * Mixing
- * ------
- *
- * Mixing is performed by summing the scaled control values.
- *
- *
- * Controls
- * --------
- *
- * Each mixer is presented with an array of controls from which it
- * selects the set that will be mixed for each actuator.
- *
- * The precise assignment of controls may vary depending on the
- * application, but the following assignments should be used
- * when appropriate.
- *
- * control | standard meaning
- * --------+-----------------------
- * 0 | roll
- * 1 | pitch
- * 2 | yaw
- * 3 | primary thrust
- */
-
-struct scaler_s {
- float negative_scale; /**< scale for inputs < 0 */
- float positive_scale; /**< scale for inputs > 0 */
- float offset; /**< bias applied to output */
- float lower_limit; /**< minimum output value */
- float upper_limit; /**< maximum output value */
- uint8_t control_group; /**< control group this scaler reads from */
- uint8_t control_index; /**< control index within the group */
-};
-
-struct mixer_s {
- unsigned control_count; /**< number of control scalers */
- struct scaler_s output_scaler; /**< scaler applied to mixer output */
- struct scaler_s control_scaler[0]; /**< array of control scalers */
-};
-
-/**
- * Handy macro for determining the allocation size of a mixer.
- */
-#define MIXER_SIZE(_num_scalers) (sizeof(struct mixer_s) + ((_num_scalers) * sizeof(struct scaler_s)))
-
-__BEGIN_DECLS
-
-/**
- * Perform a mixer calculation.
- *
- * Note that the controls array, and the arrays it indexes, are assumed
- * to be sufficiently large for any control index in the mixer.
- *
- * @param mixer Mixer configuration.
- * @param controls Array of pointers to control group values.
- * @return The mixed output.
- */
-__EXPORT float mixer_mix(struct mixer_s *mixer, float **controls);
-
-/**
- * Check a mixer configuration for sanity.
- *
- * @param mixer The mixer configuration to be checked.
- * @param group_count The highest-numbered control group that
- * should be considered legal.
- * @param control_count The highest control index that should be
- * considered legal.
- * @return Zero if the mixer configuration is sane,
- * nonzero otherwise.
- */
-__EXPORT int mixer_check(struct mixer_s *mixer, unsigned group_count, unsigned control_count);
-
-/**
- * Evaluate the control inputs to a mixer and update the bitmask of
- * required control groups.
- *
- * This function allows an actuator driver to selectively fetch just
- * the control groups required to support a particular mixer or set of
- * mixers.
- *
- * @param mixer The mixer being evaluated.
- * @param groups Pointer to a bitmask to be updated with set bits
- * corresponding to the control groups used by the
- * mixer.
- */
-__EXPORT void mixer_requires(struct mixer_s *mixer, uint32_t *groups);
-
-/**
- * Read a mixer definition from a file.
- *
- * A mixer definition is a text representation of the configuration of a
- * mixer. The definition consists of a single-line header indicating the
- * number of scalers and then one line defining each scaler. The first
- * scaler in the file is always the output scaler, followed by the input
- * scalers.
- *
- * M: <scaler count>
- * S: <control group> <control index> <negative_scale*> <positive_scale*> <offset*> <lower_limit*> <upper_limit*>
- * S: ...
- *
- * The <control ...> values for the output scaler are ignored by the mixer.
- *
- * Values marked * are integers representing floating point values; values are
- * scaled by 10000 on load/save.
- *
- * Multiple mixer definitions may be stored in a single file; it is assumed that
- * the reader will know how many to expect and read accordingly.
- *
- * A mixer entry with a scaler count of zero indicates a disabled mixer. This
- * will return NULL for the mixer when processed by this function, and will be
- * generated by passing NULL as the mixer to mixer_save.
- *
- * @param fd The file to read the definitions from.
- * @param mixer Mixer is returned here.
- * @return 1 if a mixer was read, zero on EOF or negative on error.
- */
-__EXPORT int mixer_load(int fd, struct mixer_s **mixer);
-
-/**
- * Save a mixer definition to a file.
- *
- * @param fd The file to write the definitions to.
- * @param mixer The mixer definition to save.
- * @return Zero on success, negative on error.
- */
-__EXPORT int mixer_save(int fd, struct mixer_s *mixers);
-
-
-__END_DECLS
-
-#endif /* _SYSTEMLIB_MIXER_H */
diff --git a/apps/systemlib/mixer/Makefile b/apps/systemlib/mixer/Makefile
new file mode 100644
index 000000000..f8b02f194
--- /dev/null
+++ b/apps/systemlib/mixer/Makefile
@@ -0,0 +1,39 @@
+############################################################################
+#
+# 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,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+#
+# mixer library
+#
+LIBNAME = mixerlib
+
+include $(APPDIR)/mk/app.mk
diff --git a/apps/systemlib/mixer/mixer.cpp b/apps/systemlib/mixer/mixer.cpp
new file mode 100644
index 000000000..5184c2f13
--- /dev/null
+++ b/apps/systemlib/mixer/mixer.cpp
@@ -0,0 +1,211 @@
+/****************************************************************************
+ *
+ * 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,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file mixer.cpp
+ *
+ * Programmable multi-channel mixer library.
+ */
+
+#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 "mixer.h"
+
+Mixer::Mixer(ControlCallback control_cb, uintptr_t cb_handle) :
+ _control_cb(control_cb),
+ _cb_handle(cb_handle)
+{
+}
+
+float
+Mixer::scale(const mixer_scaler_s &scaler, float input)
+{
+ float output;
+
+ if (input < 0.0f) {
+ output = (input * scaler.negative_scale) + scaler.offset;
+
+ } else {
+ output = (input * scaler.positive_scale) + scaler.offset;
+ }
+
+ if (output > scaler.max_output) {
+ output = scaler.max_output;
+
+ } else if (output < scaler.min_output) {
+ output = scaler.min_output;
+ }
+
+ return output;
+}
+
+int
+Mixer::scale_check(struct mixer_scaler_s &scaler)
+{
+ if (scaler.offset > 1.001f)
+ return 1;
+
+ if (scaler.offset < -1.001f)
+ return 2;
+
+ if (scaler.min_output > scaler.max_output)
+ return 3;
+
+ if (scaler.min_output < -1.001f)
+ return 4;
+
+ if (scaler.max_output > 1.001f)
+ return 5;
+
+ return 0;
+}
+
+/****************************************************************************/
+
+NullMixer::NullMixer() :
+ Mixer(nullptr, 0)
+{
+}
+
+unsigned
+NullMixer::mix(float *outputs, unsigned space)
+{
+ if (space > 0) {
+ *outputs = 0.0f;
+ return 1;
+ }
+ return 0;
+}
+
+void
+NullMixer::groups_required(uint32_t &groups)
+{
+
+}
+
+/****************************************************************************/
+
+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);
+}
+
+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->input_count; i++) {
+ float input;
+
+ _control_cb(_cb_handle,
+ _info->inputs[i].control_group,
+ _info->inputs[i].control_index,
+ input);
+
+ sum += scale(_info->inputs[i].scaler, input);
+ }
+ *outputs = scale(_info->output_scaler, sum);
+ return 1;
+}
+
+void
+SimpleMixer::groups_required(uint32_t &groups)
+{
+ for (unsigned i = 0; i < _info->input_count; i++)
+ groups |= 1 << _info->inputs[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->input_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->input_count; i++) {
+
+ /* verify that we can fetch the control */
+ if (_control_cb(_cb_handle,
+ _info->inputs[i].control_group,
+ _info->inputs[i].control_index,
+ junk) != 0) {
+ return -3;
+ }
+
+ /* validate the scaler */
+ ret = scale_check(_info->inputs[i].scaler);
+
+ if (ret != 0)
+ return (10 * i + ret);
+ }
+
+ return 0;
+}
diff --git a/apps/systemlib/mixer/mixer.h b/apps/systemlib/mixer/mixer.h
new file mode 100644
index 000000000..5a3857a00
--- /dev/null
+++ b/apps/systemlib/mixer/mixer.h
@@ -0,0 +1,358 @@
+/****************************************************************************
+ *
+ * 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,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file mixer.h
+ *
+ * Generic, programmable, procedural control signal mixers.
+ *
+ * This library implements a generic mixer interface that can be used
+ * by any driver or subsytem that wants to combine several control signals
+ * into a single output.
+ *
+ * Terminology
+ * ===========
+ *
+ * control value
+ * A mixer input value, typically provided by some controlling
+ * component of the system.
+ *
+ * control group
+ * A collection of controls provided by a single controlling component.
+ *
+ * actuator
+ * The mixer output value.
+ *
+ *
+ * Mixing basics
+ * =============
+ *
+ * An actuator derives its value from the combination of one or more
+ * control values. Each of the control values is scaled according to
+ * the actuator's configuration and then combined to produce the
+ * actuator value, which may then be further scaled to suit the specific
+ * output type.
+ *
+ * Internally, all scaling is performed using floating point values.
+ * Inputs and outputs are clamped to the range -1.0 to 1.0.
+ *
+ * control control control
+ * | | |
+ * v v v
+ * scale scale scale
+ * | | |
+ * | v |
+ * +-------> mix <------+
+ * |
+ * scale
+ * |
+ * v
+ * out
+ *
+ * Scaling
+ * -------
+ *
+ * Each scaler allows the input value to be scaled independently for
+ * inputs greater/less than zero. An offset can be applied to the output,
+ * as well as lower and upper boundary constraints.
+ * Negative scaling factors cause the output to be inverted (negative input
+ * produces positive output).
+ *
+ * Scaler pseudocode:
+ *
+ * if (input < 0)
+ * output = (input * NEGATIVE_SCALE) + OFFSET
+ * else
+ * output = (input * POSITIVE_SCALE) + OFFSET
+ *
+ * if (output < LOWER_LIMIT)
+ * output = LOWER_LIMIT
+ * if (output > UPPER_LIMIT)
+ * output = UPPER_LIMIT
+ *
+ *
+ * Mixing
+ * ------
+ *
+ * Mixing behaviour varies based on the specific mixer class; each
+ * mixer class describes its behaviour in more detail.
+ *
+ *
+ * Controls
+ * --------
+ *
+ * The precise assignment of controls may vary depending on the
+ * application, but the following assignments should be used
+ * when appropriate. Some mixer classes have specific assumptions
+ * about the assignment of controls.
+ *
+ * control | standard meaning
+ * --------+-----------------------
+ * 0 | roll
+ * 1 | pitch
+ * 2 | yaw
+ * 3 | primary thrust
+ */
+
+
+#ifndef _SYSTEMLIB_MIXER_MIXER_H
+#define _SYSTEMLIB_MIXER_MIXER_H value
+
+#include "drivers/drv_mixer.h"
+
+/**
+ * Abstract class defining a mixer mixing zero or more inputs to
+ * one or more outputs.
+ */
+class __EXPORT Mixer
+{
+public:
+ /** next mixer in a list */
+ Mixer *_next;
+
+ /**
+ * Fetch a control value.
+ *
+ * @param handle Token passed when the callback is registered.
+ * @param control_group The group to fetch the control from.
+ * @param control_index The group-relative index to fetch the control from.
+ * @param control The returned control
+ * @return Zero if the value was fetched, nonzero otherwise.
+ */
+ typedef int (* ControlCallback)(uintptr_t handle,
+ uint8_t control_group,
+ uint8_t control_index,
+ float &control);
+
+ /**
+ * Constructor.
+ *
+ * @param control_cb Callback invoked when reading controls.
+ */
+ Mixer(ControlCallback control_cb, uintptr_t cb_handle);
+ ~Mixer() {};
+
+ /**
+ * Perform the mixing function.
+ *
+ * @param outputs Array into which mixed output(s) should be placed.
+ * @param space The number of available entries in the output array;
+ * @return The number of entries in the output array that were populated.
+ */
+ virtual unsigned mix(float *outputs, unsigned space) = 0;
+
+ /**
+ * Analyses the mix configuration and updates a bitmask of groups
+ * that are required.
+ *
+ * @param groups A bitmask of groups (0-31) that the mixer requires.
+ */
+ virtual void groups_required(uint32_t &groups) = 0;
+
+protected:
+ /** client-supplied callback used when fetching control values */
+ ControlCallback _control_cb;
+ uintptr_t _cb_handle;
+
+ /**
+ * Perform simpler linear scaling.
+ *
+ * @param scaler The scaler configuration.
+ * @param input The value to be scaled.
+ * @return The scaled value.
+ */
+ static float scale(const mixer_scaler_s &scaler, float input);
+
+ /**
+ * Validate a scaler
+ *
+ * @param scaler The scaler to be validated.
+ * @return Zero if good, nonzero otherwise.
+ */
+ static int scale_check(struct mixer_scaler_s &scaler);
+
+private:
+};
+
+/**
+ * Group of mixers, built up from single mixers and processed
+ * in order when mixing.
+ */
+class __EXPORT MixerGroup : public Mixer
+{
+public:
+ MixerGroup(ControlCallback control_cb, uintptr_t cb_handle);
+ ~MixerGroup();
+
+ virtual unsigned mix(float *outputs, unsigned space);
+ virtual void groups_required(uint32_t &groups);
+
+ /**
+ * Add a mixer to the group.
+ *
+ * @param mixer The mixer to be added.
+ */
+ void add_mixer(Mixer *mixer);
+
+ /**
+ * Reads a mixer definition from a file and configures a corresponding
+ * group.
+ *
+ * The mixer group must be empty when this function is called.
+ *
+ * A mixer definition is a text representation of the configuration of a
+ * mixer. Definition lines begin with a capital letter followed by a colon.
+ *
+ * Null Mixer:
+ *
+ * Z:
+ *
+ * This mixer generates a constant zero output, and is normally used to
+ * skip over outputs that are not in use.
+ *
+ * Simple Mixer:
+ *
+ * M: <scaler count>
+ * S: <control group> <control index> <negative_scale*> <positive_scale*> <offset*> <lower_limit*> <upper_limit*>
+ * S: ...
+ *
+ * The definition consists of a single-line header indicating the
+ * number of scalers and then one line defining each scaler. The first
+ * scaler in the file is always the output scaler, followed by the input
+ * scalers.
+ *
+ * The <control ...> values for the output scaler are ignored by the mixer.
+ *
+ *
+ *
+ * Values marked * are integers representing floating point values; values are
+ * scaled by 10000 on load/save.
+ *
+ * Multiple mixer definitions may be stored in a single file; it is assumed that
+ * the reader will know how many to expect and read accordingly.
+ *
+ * A mixer entry with a scaler count of zero indicates a disabled mixer. This
+ * will return NULL for the mixer when processed by this function, and will be
+ * generated by passing NULL as the mixer to mixer_save.
+ *
+ * @param path The mixer configuration file to read.
+ * @return Zero on successful load, nonzero otherwise.
+ */
+ int load_from_file(const char *path);
+
+private:
+ Mixer *_first; /**< linked list of mixers */
+};
+
+/**
+ * Null mixer; returns zero.
+ *
+ * Used as a placeholder for output channels that are unassigned in groups.
+ */
+class __EXPORT NullMixer : public Mixer
+{
+public:
+ NullMixer();
+ ~NullMixer() {};
+
+ virtual unsigned mix(float *outputs, unsigned space);
+ virtual void groups_required(uint32_t &groups);
+};
+
+/**
+ * Simple summing mixer.
+ *
+ * Collects zero or more inputs and mixes them to a single output.
+ */
+class __EXPORT SimpleMixer : public Mixer
+{
+public:
+ /**
+ * Constructor
+ *
+ * @param mixinfo Mixer configuration. The pointer passed
+ * becomes the property of the mixer and
+ * will be freed when the mixer is deleted.
+ */
+ SimpleMixer(ControlCallback control_cb,
+ uintptr_t cb_handle,
+ mixer_simple_s *mixinfo);
+ ~SimpleMixer();
+
+ virtual unsigned mix(float *outputs, unsigned space);
+ virtual void groups_required(uint32_t &groups);
+
+ /**
+ * Check that the mixer configuration as loaded is sensible.
+ *
+ * Note that this function will call control_cb, but only cares about
+ * error returns, not the input value.
+ *
+ * @return Zero if the mixer makes sense, nonzero otherwise.
+ */
+ int check();
+protected:
+
+private:
+ mixer_simple_s *_info;
+};
+
+/**
+ * Multi-rotor mixer.
+ *
+ * Collects four inputs (roll, pitch, yaw, thrust) and mixes them to
+ * a set of outputs based on the configured geometry.
+ */
+class __EXPORT MultirotorMixer : public Mixer
+{
+public:
+ enum Geometry
+ {
+ MULTIROTOR_QUAD_PLUS,
+ MULTIROTOR_QUAD_X
+ /* XXX add more here */
+ };
+
+ MultirotorMixer(ControlCallback control_cb,
+ uintptr_t cb_handle,
+ Geometry geom);
+ ~MultirotorMixer();
+
+ virtual unsigned mix(float *outputs, unsigned space);
+ virtual void groups_required(uint32_t &groups);
+
+private:
+ Geometry _geometry;
+};
+
+#endif
diff --git a/apps/systemlib/mixer/mixer_group.cpp b/apps/systemlib/mixer/mixer_group.cpp
new file mode 100644
index 000000000..72a2ff3e5
--- /dev/null
+++ b/apps/systemlib/mixer/mixer_group.cpp
@@ -0,0 +1,288 @@
+/****************************************************************************
+ *
+ * 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,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file mixer_group.cpp
+ *
+ * Mixer collection.
+ */
+
+#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 "mixer.h"
+
+namespace
+{
+
+/**
+ * Effectively fdgets() with some extra smarts.
+ */
+static int
+mixer_getline(int fd, char *line, unsigned maxlen)
+{
+ /* reduce line budget by 1 to account for terminal NUL */
+ maxlen--;
+
+ /* loop looking for a non-comment line */
+ for (;;) {
+ int ret;
+ char c;
+ char *p = line;
+
+ /* loop reading characters for this line */
+ for (;;) {
+ ret = read(fd, &c, 1);
+
+ /* on error or EOF, return same */
+ if (ret <= 0)
+ return ret;
+
+ /* ignore carriage returns */
+ if (c == '\r')
+ continue;
+
+ /* line termination */
+ if (c == '\n') {
+ /* ignore malformed lines */
+ if ((p - line) < 4)
+ break;
+
+ if (line[1] != ':')
+ break;
+
+ /* terminate line as string and return */
+ *p = '\0';
+ return 1;
+ }
+
+ /* if we have space, accumulate the byte and go on */
+ if ((p - line) < maxlen)
+ *p++ = c;
+ }
+ }
+}
+
+/**
+ * Parse a scaler from the buffer.
+ */
+static int
+mixer_parse_scaler(const char *buf, mixer_scaler_s &scaler, uint8_t &control_group, uint8_t &control_index)
+{
+ unsigned u[2];
+ int s[5];
+
+ 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)
+ return -1;
+
+ 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 *
+mixer_load_simple(Mixer::ControlCallback control_cb, uintptr_t cb_handle, int fd, unsigned inputs)
+{
+ mixer_simple_s *mixinfo = nullptr;
+ char buf[60];
+ uint8_t control_group, control_index;
+ int ret;
+
+ /* let's assume we're going to read a simple mixer */
+ mixinfo = (mixer_simple_s *)malloc(MIXER_SIMPLE_SIZE(inputs));
+
+ /* first, get the output scaler */
+ ret = mixer_getline(fd, buf, sizeof(buf));
+ if (ret < 1)
+ goto fail;
+ if (mixer_parse_scaler(buf, mixinfo->output_scaler, control_group, control_index))
+ goto fail;
+
+ /* now get any inputs */
+ for (unsigned i = 0; i < inputs; i++) {
+ ret = mixer_getline(fd, buf, sizeof(buf));
+ if (ret < 1)
+ goto fail;
+ if (mixer_parse_scaler(buf,
+ mixinfo->inputs[i].scaler,
+ mixinfo->inputs[i].control_group,
+ mixinfo->inputs[i].control_index)) {
+ goto fail;
+ }
+ }
+
+ /* XXX should be a factory that validates the mixinfo ... */
+ return new SimpleMixer(control_cb, cb_handle, mixinfo);
+
+fail:
+ free(mixinfo);
+ return nullptr;
+}
+
+int
+mixer_load(Mixer::ControlCallback control_cb, uintptr_t cb_handle, int fd, Mixer *&mixer)
+{
+ int ret;
+ char buf[60];
+ unsigned scalers;
+
+ ret = mixer_getline(fd, buf, sizeof(buf));
+
+ /* end of file or error ?*/
+ if (ret < 1)
+ return ret;
+
+ /* slot is empty - allocate a null mixer */
+ if (buf[0] == 'Z') {
+ mixer = new NullMixer();
+ return 0;
+ }
+
+ /* is it a simple mixer? */
+ if (sscanf(buf, "M: %u", &scalers) == 1) {
+ mixer = mixer_load_simple(control_cb, cb_handle, fd, scalers);
+ return (mixer == nullptr) ? -1 : 0;
+ }
+
+ /* we don't recognise the mixer type */
+ return -1;
+}
+
+
+} // namespace
+
+MixerGroup::MixerGroup(ControlCallback control_cb, uintptr_t cb_handle) :
+ Mixer(control_cb, cb_handle),
+ _first(nullptr)
+{
+}
+
+MixerGroup::~MixerGroup()
+{
+ Mixer *mixer;
+
+ /* discard sub-mixers */
+ while (_first != nullptr) {
+ mixer = _first;
+ _first = mixer->_next;
+ delete mixer;
+ }
+}
+
+void
+MixerGroup::add_mixer(Mixer *mixer)
+{
+ Mixer **mpp;
+
+ mpp = &_first;
+ while (*mpp != nullptr)
+ mpp = &((*mpp)->_next);
+ *mpp = mixer;
+ mixer->_next = nullptr;
+}
+
+unsigned
+MixerGroup::mix(float *outputs, unsigned space)
+{
+ Mixer *mixer = _first;
+ unsigned index = 0;
+
+ while ((mixer != nullptr) && (index < space)) {
+ index += mixer->mix(outputs + index, space - index);
+ mixer = mixer->_next;
+ }
+ return index;
+}
+
+void
+MixerGroup::groups_required(uint32_t &groups)
+{
+ Mixer *mixer = _first;
+
+ while (mixer != nullptr) {
+ mixer->groups_required(groups);
+ mixer = mixer->_next;
+ }
+}
+
+int
+MixerGroup::load_from_file(const char *path)
+{
+ if (_first != nullptr)
+ return -1;
+
+ int fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return -1;
+
+ for (;;) {
+ int result;
+ Mixer *mixer;
+
+ result = mixer_load(_control_cb,
+ _cb_handle,
+ fd,
+ mixer);
+
+ /* error? */
+ if (result < 0)
+ return -1;
+
+ /* EOF or error */
+ if (result < 1)
+ break;
+
+ add_mixer(mixer);
+ }
+
+ close(fd);
+ return 0;
+}
diff --git a/apps/systemlib/mixer/mixer_multirotor.cpp b/apps/systemlib/mixer/mixer_multirotor.cpp
new file mode 100644
index 000000000..713b1e25d
--- /dev/null
+++ b/apps/systemlib/mixer/mixer_multirotor.cpp
@@ -0,0 +1,81 @@
+/****************************************************************************
+ *
+ * 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,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file mixer_multirotor.cpp
+ *
+ * Multi-rotor mixers.
+ */
+
+#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 "mixer.h"
+
+MultirotorMixer::MultirotorMixer(ControlCallback control_cb,
+ uintptr_t cb_handle,
+ MultirotorMixer::Geometry geom) :
+ Mixer(control_cb, cb_handle),
+ _geometry(geom)
+{
+}
+
+MultirotorMixer::~MultirotorMixer()
+{
+}
+
+unsigned
+MultirotorMixer::mix(float *outputs, unsigned space)
+{
+ /* XXX implement this */
+ return 0;
+}
+
+void
+MultirotorMixer::groups_required(uint32_t &groups)
+{
+ /* XXX for now, hardcoded to indexes 0-3 in control group zero */
+ groups |= (1 << 0);
+}
+
diff --git a/nuttx/configs/px4fmu/nsh/appconfig b/nuttx/configs/px4fmu/nsh/appconfig
index 585348b81..84bfc653a 100644
--- a/nuttx/configs/px4fmu/nsh/appconfig
+++ b/nuttx/configs/px4fmu/nsh/appconfig
@@ -43,6 +43,7 @@ CONFIGURED_APPS += system/readline
# System library - utility functions
CONFIGURED_APPS += systemlib
+CONFIGURED_APPS += systemlib/mixer
CONFIGURED_APPS += systemcmds/reboot
CONFIGURED_APPS += systemcmds/perf