/****************************************************************************
*
* Copyright (c) 2014 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 sf0x.cpp
* @author Lorenz Meier <lm@inf.ethz.ch>
* @author Greg Hulands
*
* Driver for the Lightware SF0x laser rangefinder series
*/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdbool.h>
#include <semaphore.h>
#include <string.h>
#include <fcntl.h>
#include <poll.h>
#include <errno.h>
#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <termios.h>
#include <nuttx/arch.h>
#include <nuttx/wqueue.h>
#include <nuttx/clock.h>
#include <systemlib/perf_counter.h>
#include <systemlib/err.h>
#include <drivers/drv_hrt.h>
#include <drivers/drv_range_finder.h>
#include <drivers/device/device.h>
#include <drivers/device/ringbuffer.h>
#include <uORB/uORB.h>
#include <uORB/topics/subsystem_info.h>
#include <board_config.h>
/* Configuration Constants */
/* oddly, ERROR is not defined for c++ */
#ifdef ERROR
# undef ERROR
#endif
static const int ERROR = -1;
#ifndef CONFIG_SCHED_WORKQUEUE
# error This requires CONFIG_SCHED_WORKQUEUE.
#endif
#define SF0X_CONVERSION_INTERVAL 83334
#define SF0X_TAKE_RANGE_REG 'd'
#define SF02F_MIN_DISTANCE 0.0f
#define SF02F_MAX_DISTANCE 40.0f
#define SF0X_DEFAULT_PORT "/dev/ttyS2"
class SF0X : public device::CDev
{
public:
SF0X(const char *port = SF0X_DEFAULT_PORT);
virtual ~SF0X();
virtual int init();
virtual ssize_t read(struct file *filp, char *buffer, size_t buflen);
virtual int ioctl(struct file *filp, int cmd, unsigned long arg);
/**
* Diagnostics - print some basic information about the driver.
*/
void print_info();
protected:
virtual int probe();
private:
float _min_distance;
float _max_distance;
work_s _work;
RingBuffer *_reports;
bool _sensor_ok;
int _measure_ticks;
bool _collect_phase;
int _fd;
char _linebuf[10];
unsigned _linebuf_index;
hrt_abstime _last_read;
orb_advert_t _range_finder_topic;
unsigned _consecutive_fail_count;
perf_counter_t _sample_perf;
perf_counter_t _comms_errors;
perf_counter_t _buffer_overflows;
/**
* Initialise the automatic measurement state machine and start it.
*
* @note This function is called at open and error time. It might make sense
* to make it more aggressive about resetting the bus in case of errors.
*/
void start();
/**
* Stop the automatic measurement state machine.
*/
void stop();
/**
* Set the min and max distance thresholds if you want the end points of the sensors
* range to be brought in at all, otherwise it will use the defaults SF0X_MIN_DISTANCE
* and SF0X_MAX_DISTANCE
*/
void set_minimum_distance(float min);
void set_maximum_distance(float max);
float get_minimum_distance();
float get_maximum_distance();
/**
* Perform a poll cycle; collect from the previous measurement
* and start a new one.
*/
void cycle();
int measure();
int collect();
/**
* Static trampoline from the workq context; because we don't have a
* generic workq wrapper yet.
*
* @param arg Instance pointer for the driver that is polling.
*/
static void cycle_trampoline(void *arg);
};
/*
* Driver 'main' command.
*/
extern "C" __EXPORT int sf0x_main(int argc, char *argv[]);
SF0X::SF0X(const char *port) :
CDev("SF0X", RANGE_FINDER_DEVICE_PATH),
_min_distance(SF02F_MIN_DISTANCE),
_max_distance(SF02F_MAX_DISTANCE),
_reports(nullptr),
_sensor_ok(false),
_measure_ticks(0),
_collect_phase(false),
_fd(-1),
_linebuf_index(0),
_last_read(0),
_range_finder_topic(-1),
_consecutive_fail_count(0),
_sample_perf(perf_alloc(PC_ELAPSED, "sf0x_read")),
_comms_errors(perf_alloc(PC_COUNT, "sf0x_comms_errors")),
_buffer_overflows(perf_alloc(PC_COUNT, "sf0x_buffer_overflows"))
{
/* open fd */
_fd = ::open(port, O_RDWR | O_NOCTTY | O_NONBLOCK);
if (_fd < 0) {
warnx("FAIL: laser fd");
}
/* tell it to stop auto-triggering */
char stop_auto = ' ';
(void)::write(_fd, &stop_auto, 1);
usleep(100);
(void)::write(_fd, &stop_auto, 1);
struct termios uart_config;
int termios_state;
/* fill the struct for the new configuration */
tcgetattr(_fd, &uart_config);
/* clear ONLCR flag (which appends a CR for every LF) */
uart_config.c_oflag &= ~ONLCR;
/* no parity, one stop bit */
uart_config.c_cflag &= ~(CSTOPB | PARENB);
unsigned speed = B9600;
/* set baud rate */
if ((termios_state = cfsetispeed(&uart_config, speed)) < 0) {
warnx("ERR CFG: %d ISPD", termios_state);
}
if ((termios_state = cfsetospeed(&uart_config, speed)) < 0) {
warnx("ERR CFG: %d OSPD\n", termios_state);
}
if ((termios_state = tcsetattr(_fd, TCSANOW, &uart_config)) < 0) {
warnx("ERR baud %d ATTR", termios_state);
}
// disable debug() calls
_debug_enabled = false;
// work_cancel in the dtor will explode if we don't do this...
memset(&_work, 0, sizeof(_work));
}
SF0X::~SF0X()
{
/* make sure we are truly inactive */
stop();
/* free any existing reports */
if (_reports != nullptr) {
delete _reports;
}
}
int
SF0X::init()
{
int ret = ERROR;
unsigned i = 0;
/* do regular cdev init */
if (CDev::init() != OK) {
goto out;
}
/* allocate basic report buffers */
_reports = new RingBuffer(2, sizeof(range_finder_report));
if (_reports == nullptr) {
warnx("mem err");
goto out;
}
/* get a publish handle on the range finder topic */
struct range_finder_report zero_report;
memset(&zero_report, 0, sizeof(zero_report));
_range_finder_topic = orb_advertise(ORB_ID(sensor_range_finder), &zero_report);
if (_range_finder_topic < 0) {
warnx("advert err");
}
/* close the fd */
::close(_fd);
_fd = -1;
out:
return OK;
}
int
SF0X::probe()
{
return measure();
}
void
SF0X::set_minimum_distance(float min)
{
_min_distance = min;
}
void
SF0X::set_maximum_distance(float max)
{
_max_distance = max;
}
float
SF0X::get_minimum_distance()
{
return _min_distance;
}
float
SF0X::get_maximum_distance()
{
return _max_distance;
}
int
SF0X::ioctl(struct file *filp, int cmd, unsigned long arg)
{
switch (cmd) {
case SENSORIOCSPOLLRATE: {
switch (arg) {
/* switching to manual polling */
case SENSOR_POLLRATE_MANUAL:
stop();
_measure_ticks = 0;
return OK;
/* external signalling (DRDY) not supported */
case SENSOR_POLLRATE_EXTERNAL:
/* zero would be bad */
case 0:
return -EINVAL;
/* set default/max polling rate */
case SENSOR_POLLRATE_MAX:
case SENSOR_POLLRATE_DEFAULT: {
/* do we need to start internal polling? */
bool want_start = (_measure_ticks == 0);
/* set interval for next measurement to minimum legal value */
_measure_ticks = USEC2TICK(SF0X_CONVERSION_INTERVAL);
/* if we need to start the poll state machine, do it */
if (want_start) {
start();
}
return OK;
}
/* adjust to a legal polling interval in Hz */
default: {
/* do we need to start internal polling? */
bool want_start = (_measure_ticks == 0);
/* convert hz to tick interval via microseconds */
unsigned ticks = USEC2TICK(1000000 / arg);
/* check against maximum rate */
if (ticks < USEC2TICK(SF0X_CONVERSION_INTERVAL)) {
return -EINVAL;
}
/* update interval for next measurement */
_measure_ticks = ticks;
/* if we need to start the poll state machine, do it */
if (want_start) {
start();
}
return OK;
}
}
}
case SENSORIOCGPOLLRATE:
if (_measure_ticks == 0) {
return SENSOR_POLLRATE_MANUAL;
}
return (1000 / _measure_ticks);
case SENSORIOCSQUEUEDEPTH: {
/* lower bound is mandatory, upper bound is a sanity check */
if ((arg < 1) || (arg > 100)) {
return -EINVAL;
}
irqstate_t flags = irqsave();
if (!_reports->resize(arg)) {
irqrestore(flags);
return -ENOMEM;
}
irqrestore(flags);
return OK;
}
case SENSORIOCGQUEUEDEPTH:
return _reports->size();
case SENSORIOCRESET:
/* XXX implement this */
return -EINVAL;
case RANGEFINDERIOCSETMINIUMDISTANCE: {
set_minimum_distance(*(float *)arg);
return 0;
}
break;
case RANGEFINDERIOCSETMAXIUMDISTANCE: {
set_maximum_distance(*(float *)arg);
return 0;
}
break;
default:
/* give it to the superclass */
return CDev::ioctl(filp, cmd, arg);
}
}
ssize_t
SF0X::read(struct file *filp, char *buffer, size_t buflen)
{
unsigned count = buflen / sizeof(struct range_finder_report);
struct range_finder_report *rbuf = reinterpret_cast<struct range_finder_report *>(buffer);
int ret = 0;
/* buffer must be large enough */
if (count < 1) {
return -ENOSPC;
}
/* if automatic measurement is enabled */
if (_measure_ticks > 0) {
/*
* While there is space in the caller's buffer, and reports, copy them.
* Note that we may be pre-empted by the workq thread while we are doing this;
* we are careful to avoid racing with them.
*/
while (count--) {
if (_reports->get(rbuf)) {
ret += sizeof(*rbuf);
rbuf++;
}
}
/* if there was no data, warn the caller */
return ret ? ret : -EAGAIN;
}
/* manual measurement - run one conversion */
do {
_reports->flush();
/* trigger a measurement */
if (OK != measure()) {
ret = -EIO;
break;
}
/* wait for it to complete */
usleep(SF0X_CONVERSION_INTERVAL);
/* run the collection phase */
if (OK != collect()) {
ret = -EIO;
break;
}
/* state machine will have generated a report, copy it out */
if (_reports->get(rbuf)) {
ret = sizeof(*rbuf);
}
} while (0);
return ret;
}
int
SF0X::measure()
{
int ret;
/*
* Send the command to begin a measurement.
*/
char cmd = SF0X_TAKE_RANGE_REG;
ret = ::write(_fd, &cmd, 1);
if (ret != sizeof(cmd)) {
perf_count(_comms_errors);
log("write fail %d", ret);
return ret;
}
ret = OK;
return ret;
}
int
SF0X::collect()
{
int ret;
perf_begin(_sample_perf);
/* clear buffer if last read was too long ago */
uint64_t read_elapsed = hrt_elapsed_time(&_last_read);
if (read_elapsed > (SF0X_CONVERSION_INTERVAL * 2)) {
_linebuf_index = 0;
} else if (_linebuf_index > 0) {
/* increment to next read position */
_linebuf_index++;
}
/* the buffer for read chars is buflen minus null termination */
unsigned readlen = sizeof(_linebuf) - 1;
/* read from the sensor (uart buffer) */
ret = ::read(_fd, &_linebuf[_linebuf_index], readlen - _linebuf_index);
if (ret < 0) {
_linebuf[sizeof(_linebuf) - 1] = '\0';
debug("read err: %d lbi: %d buf: %s", ret, (int)_linebuf_index, _linebuf);
perf_count(_comms_errors);
perf_end(_sample_perf);
/* only throw an error if we time out */
if (read_elapsed > (SF0X_CONVERSION_INTERVAL * 2)) {
return ret;
} else {
return -EAGAIN;
}
} else if (ret == 0) {
return -EAGAIN;
}
/* we did increment the index to the next position already, so just add the additional fields */
_linebuf_index += (ret - 1);
_last_read = hrt_absolute_time();
if (_linebuf_index < 1) {
/* we need at least the two end bytes to make sense of this string */
return -EAGAIN;
} else if (_linebuf[_linebuf_index - 1] != '\r' || _linebuf[_linebuf_index] != '\n') {
if (_linebuf_index >= readlen - 1) {
/* we have a full buffer, but no line ending - abort */
_linebuf_index = 0;
perf_count(_comms_errors);
return -ENOMEM;
} else {
/* incomplete read, reschedule ourselves */
return -EAGAIN;
}
}
char *end;
float si_units;
bool valid;
/* enforce line ending */
unsigned lend = (_linebuf_index < (sizeof(_linebuf) - 1)) ? _linebuf_index : (sizeof(_linebuf) - 1);
_linebuf[lend] = '\0';
if (_linebuf[0] == '-' && _linebuf[1] == '-' && _linebuf[2] == '.') {
si_units = -1.0f;
valid = false;
} else {
/* we need to find a dot in the string, as we're missing the meters part else */
valid = false;
/* wipe out partially read content from last cycle(s), check for dot */
for (int i = 0; i < (lend - 2); i++) {
if (_linebuf[i] == '\n') {
char buf[sizeof(_linebuf)];
memcpy(buf, &_linebuf[i+1], (lend + 1) - (i + 1));
memcpy(_linebuf, buf, (lend + 1) - (i + 1));
}
if (_linebuf[i] == '.') {
valid = true;
}
}
if (valid) {
si_units = strtod(_linebuf, &end);
/* we require at least 3 characters for a valid number */
if (end > _linebuf + 3) {
valid = true;
} else {
si_units = -1.0f;
valid = false;
}
}
}
debug("val (float): %8.4f, raw: %s, valid: %s\n", si_units, _linebuf, ((valid) ? "OK" : "NO"));
/* done with this chunk, resetting - even if invalid */
_linebuf_index = 0;
/* if its invalid, there is no reason to forward the value */
if (!valid) {
perf_count(_comms_errors);
return -EINVAL;
}
struct range_finder_report report;
/* this should be fairly close to the end of the measurement, so the best approximation of the time */
report.timestamp = hrt_absolute_time();
report.error_count = perf_event_count(_comms_errors);
report.distance = si_units;
report.valid = valid && (si_units > get_minimum_distance() && si_units < get_maximum_distance() ? 1 : 0);
/* publish it */
orb_publish(ORB_ID(sensor_range_finder), _range_finder_topic, &report);
if (_reports->force(&report)) {
perf_count(_buffer_overflows);
}
/* notify anyone waiting for data */
poll_notify(POLLIN);
ret = OK;
perf_end(_sample_perf);
return ret;
}
void
SF0X::start()
{
/* reset the report ring and state machine */
_collect_phase = false;
_reports->flush();
/* schedule a cycle to start things */
work_queue(HPWORK, &_work, (worker_t)&SF0X::cycle_trampoline, this, 1);
// /* notify about state change */
// struct subsystem_info_s info = {
// true,
// true,
// true,
// SUBSYSTEM_TYPE_RANGEFINDER
// };
// static orb_advert_t pub = -1;
// if (pub > 0) {
// orb_publish(ORB_ID(subsystem_info), pub, &info);
// } else {
// pub = orb_advertise(ORB_ID(subsystem_info), &info);
// }
}
void
SF0X::stop()
{
work_cancel(HPWORK, &_work);
}
void
SF0X::cycle_trampoline(void *arg)
{
SF0X *dev = static_cast<SF0X *>(arg);
dev->cycle();
}
void
SF0X::cycle()
{
/* fds initialized? */
if (_fd < 0) {
/* open fd */
_fd = ::open(SF0X_DEFAULT_PORT, O_RDWR | O_NOCTTY | O_NONBLOCK);
}
/* collection phase? */
if (_collect_phase) {
/* perform collection */
int collect_ret = collect();
if (collect_ret == -EAGAIN) {
/* reschedule to grab the missing bits, time to transmit 10 bytes @9600 bps */
work_queue(HPWORK,
&_work,
(worker_t)&SF0X::cycle_trampoline,
this,
USEC2TICK(1100));
return;
}
if (OK != collect_ret) {
/* we know the sensor needs about four seconds to initialize */
if (hrt_absolute_time() > 5 * 1000 * 1000LL && _consecutive_fail_count < 5) {
log("collection error #%u", _consecutive_fail_count);
}
_consecutive_fail_count++;
/* restart the measurement state machine */
start();
return;
} else {
/* apparently success */
_consecutive_fail_count = 0;
}
/* next phase is measurement */
_collect_phase = false;
/*
* Is there a collect->measure gap?
*/
if (_measure_ticks > USEC2TICK(SF0X_CONVERSION_INTERVAL)) {
/* schedule a fresh cycle call when we are ready to measure again */
work_queue(HPWORK,
&_work,
(worker_t)&SF0X::cycle_trampoline,
this,
_measure_ticks - USEC2TICK(SF0X_CONVERSION_INTERVAL));
return;
}
}
/* measurement phase */
if (OK != measure()) {
log("measure error");
}
/* next phase is collection */
_collect_phase = true;
/* schedule a fresh cycle call when the measurement is done */
work_queue(HPWORK,
&_work,
(worker_t)&SF0X::cycle_trampoline,
this,
USEC2TICK(SF0X_CONVERSION_INTERVAL));
}
void
SF0X::print_info()
{
perf_print_counter(_sample_perf);
perf_print_counter(_comms_errors);
perf_print_counter(_buffer_overflows);
printf("poll interval: %d ticks\n", _measure_ticks);
_reports->print_info("report queue");
}
/**
* Local functions in support of the shell command.
*/
namespace sf0x
{
/* oddly, ERROR is not defined for c++ */
#ifdef ERROR
# undef ERROR
#endif
const int ERROR = -1;
SF0X *g_dev;
void start();
void stop();
void test();
void reset();
void info();
/**
* Start the driver.
*/
void
start(const char *port)
{
int fd;
if (g_dev != nullptr) {
errx(1, "already started");
}
/* create the driver */
g_dev = new SF0X(port);
if (g_dev == nullptr) {
goto fail;
}
if (OK != g_dev->init()) {
goto fail;
}
/* set the poll rate to default, starts automatic data collection */
fd = open(RANGE_FINDER_DEVICE_PATH, 0);
if (fd < 0) {
warnx("device open fail");
goto fail;
}
if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0) {
goto fail;
}
exit(0);
fail:
if (g_dev != nullptr) {
delete g_dev;
g_dev = nullptr;
}
errx(1, "driver start failed");
}
/**
* Stop the driver
*/
void stop()
{
if (g_dev != nullptr) {
delete g_dev;
g_dev = nullptr;
} else {
errx(1, "driver not running");
}
exit(0);
}
/**
* Perform some basic functional tests on the driver;
* make sure we can collect data from the sensor in polled
* and automatic modes.
*/
void
test()
{
struct range_finder_report report;
ssize_t sz;
int fd = open(RANGE_FINDER_DEVICE_PATH, O_RDONLY);
if (fd < 0) {
err(1, "%s open failed (try 'sf0x start' if the driver is not running", RANGE_FINDER_DEVICE_PATH);
}
/* do a simple demand read */
sz = read(fd, &report, sizeof(report));
if (sz != sizeof(report)) {
err(1, "immediate read failed");
}
warnx("single read");
warnx("val: %0.2f m", (double)report.distance);
warnx("time: %lld", report.timestamp);
/* start the sensor polling at 2 Hz rate */
if (OK != ioctl(fd, SENSORIOCSPOLLRATE, 2)) {
errx(1, "failed to set 2Hz poll rate");
}
/* read the sensor 5x and report each value */
for (unsigned i = 0; i < 5; i++) {
struct pollfd fds;
/* wait for data to be ready */
fds.fd = fd;
fds.events = POLLIN;
int ret = poll(&fds, 1, 2000);
if (ret != 1) {
warnx("timed out");
break;
}
/* now go get it */
sz = read(fd, &report, sizeof(report));
if (sz != sizeof(report)) {
warnx("read failed: got %d vs exp. %d", sz, sizeof(report));
break;
}
warnx("read #%u", i);
warnx("val: %0.3f m", (double)report.distance);
warnx("time: %lld", report.timestamp);
}
/* reset the sensor polling to the default rate */
if (OK != ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT)) {
errx(1, "ERR: DEF RATE");
}
errx(0, "PASS");
}
/**
* Reset the driver.
*/
void
reset()
{
int fd = open(RANGE_FINDER_DEVICE_PATH, O_RDONLY);
if (fd < 0) {
err(1, "failed ");
}
if (ioctl(fd, SENSORIOCRESET, 0) < 0) {
err(1, "driver reset failed");
}
if (ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT) < 0) {
err(1, "driver poll restart failed");
}
exit(0);
}
/**
* Print a little info about the driver.
*/
void
info()
{
if (g_dev == nullptr) {
errx(1, "driver not running");
}
printf("state @ %p\n", g_dev);
g_dev->print_info();
exit(0);
}
} // namespace
int
sf0x_main(int argc, char *argv[])
{
/*
* Start/load the driver.
*/
if (!strcmp(argv[1], "start")) {
if (argc > 2) {
sf0x::start(argv[2]);
} else {
sf0x::start(SF0X_DEFAULT_PORT);
}
}
/*
* Stop the driver
*/
if (!strcmp(argv[1], "stop")) {
sf0x::stop();
}
/*
* Test the driver/device.
*/
if (!strcmp(argv[1], "test")) {
sf0x::test();
}
/*
* Reset the driver.
*/
if (!strcmp(argv[1], "reset")) {
sf0x::reset();
}
/*
* Print driver information.
*/
if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status")) {
sf0x::info();
}
errx(1, "unrecognized command, try 'start', 'test', 'reset' or 'info'");
}