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/**
* @file ets_airspeed.cpp
* @author Simon Wilks
*
* Driver for the Eagle Tree Airspeed V3 connected via I2C.
*/
#include <nuttx/config.h>
#include <drivers/device/i2c.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 <nuttx/arch.h>
#include <nuttx/wqueue.h>
#include <nuttx/clock.h>
#include <board_config.h>
#include <systemlib/airspeed.h>
#include <systemlib/err.h>
#include <systemlib/param/param.h>
#include <systemlib/perf_counter.h>
#include <drivers/drv_airspeed.h>
#include <drivers/drv_hrt.h>
#include <drivers/device/ringbuffer.h>
#include <uORB/uORB.h>
#include <uORB/topics/differential_pressure.h>
#include <uORB/topics/subsystem_info.h>
#include <drivers/airspeed/airspeed.h>
/* I2C bus address */
#define I2C_ADDRESS 0x75 /* 7-bit address. 8-bit address is 0xEA */
#define ETS_PATH "/dev/ets_airspeed"
/* Register address */
#define READ_CMD 0x07 /* Read the data */
/**
* The Eagle Tree Airspeed V3 cannot provide accurate reading below speeds of 15km/h.
* You can set this value to 12 if you want a zero reading below 15km/h.
*/
#define MIN_ACCURATE_DIFF_PRES_PA 0
/* Measurement rate is 100Hz */
#define CONVERSION_INTERVAL (1000000 / 100) /* microseconds */
class ETSAirspeed : public Airspeed
{
public:
ETSAirspeed(int bus, int address = I2C_ADDRESS, const char* path = ETS_PATH);
protected:
/**
* Perform a poll cycle; collect from the previous measurement
* and start a new one.
*/
virtual void cycle();
virtual int measure();
virtual int collect();
};
/*
* Driver 'main' command.
*/
extern "C" __EXPORT int ets_airspeed_main(int argc, char *argv[]);
ETSAirspeed::ETSAirspeed(int bus, int address, const char* path) : Airspeed(bus, address,
CONVERSION_INTERVAL, path)
{
}
int
ETSAirspeed::measure()
{
int ret;
/*
* Send the command to begin a measurement.
*/
uint8_t cmd = READ_CMD;
ret = transfer(&cmd, 1, nullptr, 0);
if (OK != ret) {
perf_count(_comms_errors);
}
return ret;
}
int
ETSAirspeed::collect()
{
int ret = -EIO;
/* read from the sensor */
uint8_t val[2] = {0, 0};
perf_begin(_sample_perf);
ret = transfer(nullptr, 0, &val[0], 2);
if (ret < 0) {
perf_count(_comms_errors);
return ret;
}
uint16_t diff_pres_pa_raw = val[1] << 8 | val[0];
uint16_t diff_pres_pa;
if (diff_pres_pa_raw == 0) {
// a zero value means the pressure sensor cannot give us a
// value. We need to return, and not report a value or the
// caller could end up using this value as part of an
// average
perf_count(_comms_errors);
log("zero value from sensor");
return -1;
}
if (diff_pres_pa_raw < _diff_pres_offset + MIN_ACCURATE_DIFF_PRES_PA) {
diff_pres_pa = 0;
} else {
diff_pres_pa = diff_pres_pa_raw - _diff_pres_offset;
}
// Track maximum differential pressure measured (so we can work out top speed).
if (diff_pres_pa > _max_differential_pressure_pa) {
_max_differential_pressure_pa = diff_pres_pa;
}
differential_pressure_s report;
report.timestamp = hrt_absolute_time();
report.error_count = perf_event_count(_comms_errors);
report.differential_pressure_pa = (float)diff_pres_pa;
// XXX we may want to smooth out the readings to remove noise.
report.differential_pressure_filtered_pa = (float)diff_pres_pa;
report.differential_pressure_raw_pa = (float)diff_pres_pa_raw;
report.temperature = -1000.0f;
report.voltage = 0;
report.max_differential_pressure_pa = _max_differential_pressure_pa;
if (_airspeed_pub > 0 && !(_pub_blocked)) {
/* publish it */
orb_publish(ORB_ID(differential_pressure), _airspeed_pub, &report);
}
new_report(report);
/* notify anyone waiting for data */
poll_notify(POLLIN);
ret = OK;
perf_end(_sample_perf);
return ret;
}
void
ETSAirspeed::cycle()
{
int ret;
/* collection phase? */
if (_collect_phase) {
/* perform collection */
ret = collect();
if (OK != ret) {
perf_count(_comms_errors);
/* restart the measurement state machine */
start();
_sensor_ok = false;
return;
}
/* next phase is measurement */
_collect_phase = false;
/*
* Is there a collect->measure gap?
*/
if (_measure_ticks > USEC2TICK(CONVERSION_INTERVAL)) {
/* schedule a fresh cycle call when we are ready to measure again */
work_queue(HPWORK,
&_work,
(worker_t)&Airspeed::cycle_trampoline,
this,
_measure_ticks - USEC2TICK(CONVERSION_INTERVAL));
return;
}
}
/* measurement phase */
ret = measure();
if (OK != ret) {
debug("measure error");
}
_sensor_ok = (ret == OK);
/* next phase is collection */
_collect_phase = true;
/* schedule a fresh cycle call when the measurement is done */
work_queue(HPWORK,
&_work,
(worker_t)&Airspeed::cycle_trampoline,
this,
USEC2TICK(CONVERSION_INTERVAL));
}
/**
* Local functions in support of the shell command.
*/
namespace ets_airspeed
{
/* oddly, ERROR is not defined for c++ */
#ifdef ERROR
# undef ERROR
#endif
const int ERROR = -1;
ETSAirspeed *g_dev;
void start(int i2c_bus);
void stop();
void test();
void reset();
void info();
/**
* Start the driver.
*/
void
start(int i2c_bus)
{
int fd;
if (g_dev != nullptr)
errx(1, "already started");
/* create the driver */
g_dev = new ETSAirspeed(i2c_bus);
if (g_dev == nullptr)
goto fail;
if (OK != g_dev->Airspeed::init())
goto fail;
/* set the poll rate to default, starts automatic data collection */
fd = open(AIRSPEED_DEVICE_PATH, O_RDONLY);
if (fd < 0)
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, "no ETS airspeed sensor connected");
}
/**
* 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 differential_pressure_s report;
ssize_t sz;
int ret;
int fd = open(AIRSPEED_DEVICE_PATH, O_RDONLY);
if (fd < 0)
err(1, "%s open failed (try 'ets_airspeed start' if the driver is not running", AIRSPEED_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("diff pressure: %d pa", report.differential_pressure_pa);
/* start the sensor polling at 2Hz */
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;
ret = poll(&fds, 1, 2000);
if (ret != 1)
errx(1, "timed out waiting for sensor data");
/* now go get it */
sz = read(fd, &report, sizeof(report));
if (sz != sizeof(report))
err(1, "periodic read failed");
warnx("periodic read %u", i);
warnx("diff pressure: %d pa", report.differential_pressure_pa);
}
/* reset the sensor polling to its default rate */
if (OK != ioctl(fd, SENSORIOCSPOLLRATE, SENSOR_POLLRATE_DEFAULT))
errx(1, "failed to set default rate");
errx(0, "PASS");
}
/**
* Reset the driver.
*/
void
reset()
{
int fd = open(AIRSPEED_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
static void
ets_airspeed_usage()
{
warnx("usage: ets_airspeed command [options]");
warnx("options:");
warnx("\t-b --bus i2cbus (%d)", PX4_I2C_BUS_DEFAULT);
warnx("command:");
warnx("\tstart|stop|reset|test|info");
}
int
ets_airspeed_main(int argc, char *argv[])
{
int i2c_bus = PX4_I2C_BUS_DEFAULT;
int i;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-b") == 0 || strcmp(argv[i], "--bus") == 0) {
if (argc > i + 1) {
i2c_bus = atoi(argv[i + 1]);
}
}
}
/*
* Start/load the driver.
*/
if (!strcmp(argv[1], "start"))
ets_airspeed::start(i2c_bus);
/*
* Stop the driver
*/
if (!strcmp(argv[1], "stop"))
ets_airspeed::stop();
/*
* Test the driver/device.
*/
if (!strcmp(argv[1], "test"))
ets_airspeed::test();
/*
* Reset the driver.
*/
if (!strcmp(argv[1], "reset"))
ets_airspeed::reset();
/*
* Print driver information.
*/
if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status"))
ets_airspeed::info();
ets_airspeed_usage();
exit(0);
}