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*
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*
* 1. Redistributions of source code must retain the above copyright
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/**
* @file meas_airspeed.cpp
* @author Lorenz Meier
* @author Sarthak Kaingade
* @author Simon Wilks
*
* Driver for the MEAS Spec series connected via I2C.
*
* Supported sensors:
*
* - MS4525DO (http://www.meas-spec.com/downloads/MS4525DO.pdf)
* - untested: MS5525DSO (http://www.meas-spec.com/downloads/MS5525DSO.pdf)
*
* Interface application notes:
*
* - Interfacing to MEAS Digital Pressure Modules (http://www.meas-spec.com/downloads/Interfacing_to_MEAS_Digital_Pressure_Modules.pdf)
*/
#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 <uORB/uORB.h>
#include <uORB/topics/differential_pressure.h>
#include <uORB/topics/subsystem_info.h>
#include <drivers/airspeed/airspeed.h>
/* I2C bus address is 1010001x */
#define I2C_ADDRESS_MS4525DO 0x28 //0x51 /* 7-bit address. */
/* The MS5525DSO address is 111011Cx, where C is the complementary value of the pin CSB */
#define I2C_ADDRESS_MS5525DSO 0x77 //0x77/* 7-bit address, addr. pin pulled low */
/* Register address */
#define ADDR_READ_MR 0x00 /* write to this address to start conversion */
/* Measurement rate is 100Hz */
#define CONVERSION_INTERVAL (1000000 / 100) /* microseconds */
class MEASAirspeed : public Airspeed
{
public:
MEASAirspeed(int bus, int address = I2C_ADDRESS_MS4525DO);
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 meas_airspeed_main(int argc, char *argv[]);
MEASAirspeed::MEASAirspeed(int bus, int address) : Airspeed(bus, address,
CONVERSION_INTERVAL)
{
}
int
MEASAirspeed::measure()
{
int ret;
/*
* Send the command to begin a measurement.
*/
uint8_t cmd = 0;
ret = transfer(&cmd, 1, nullptr, 0);
if (OK != ret) {
perf_count(_comms_errors);
log("i2c::transfer returned %d", ret);
return ret;
}
ret = OK;
return ret;
}
int
MEASAirspeed::collect()
{
int ret = -EIO;
/* read from the sensor */
uint8_t val[4] = {0, 0, 0, 0};
perf_begin(_sample_perf);
ret = transfer(nullptr, 0, &val[0], 4);
if (ret < 0) {
log("error reading from sensor: %d", ret);
return ret;
}
uint8_t status = val[0] & 0xC0;
if (status == 2) {
log("err: stale data");
} else if (status == 3) {
log("err: fault");
}
//uint16_t diff_pres_pa = (val[1]) | ((val[0] & ~(0xC0)) << 8);
uint16_t temp = (val[3] & 0xE0) << 8 | val[2];
// XXX leaving this in until new calculation method has been cross-checked
//diff_pres_pa = abs(diff_pres_pa - (16384 / 2.0f));
//diff_pres_pa -= _diff_pres_offset;
int16_t dp_raw = 0, dT_raw = 0;
dp_raw = (val[0] << 8) + val[1];
dp_raw = 0x3FFF & dp_raw;
dT_raw = (val[2] << 8) + val[3];
dT_raw = (0xFFE0 & dT_raw) >> 5;
float temperature = ((200 * dT_raw) / 2047) - 50;
// XXX we may want to smooth out the readings to remove noise.
// Calculate differential pressure. As its centered around 8000
// and can go positive or negative, enforce absolute value
uint16_t diff_press_pa = abs(dp_raw - (16384 / 2.0f));
_reports[_next_report].timestamp = hrt_absolute_time();
_reports[_next_report].temperature = temperature;
_reports[_next_report].differential_pressure_pa = diff_press_pa;
// Track maximum differential pressure measured (so we can work out top speed).
if (diff_press_pa > _reports[_next_report].max_differential_pressure_pa) {
_reports[_next_report].max_differential_pressure_pa = diff_press_pa;
}
/* announce the airspeed if needed, just publish else */
orb_publish(ORB_ID(differential_pressure), _airspeed_pub, &_reports[_next_report]);
/* post a report to the ring - note, not locked */
INCREMENT(_next_report, _num_reports);
/* if we are running up against the oldest report, toss it */
if (_next_report == _oldest_report) {
perf_count(_buffer_overflows);
INCREMENT(_oldest_report, _num_reports);
}
/* notify anyone waiting for data */
poll_notify(POLLIN);
ret = OK;
perf_end(_sample_perf);
return ret;
}
void
MEASAirspeed::cycle()
{
/* collection phase? */
if (_collect_phase) {
/* perform collection */
if (OK != collect()) {
log("collection error");
/* restart the measurement state machine */
start();
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 */
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)&Airspeed::cycle_trampoline,
this,
USEC2TICK(CONVERSION_INTERVAL));
}
/**
* Local functions in support of the shell command.
*/
namespace meas_airspeed
{
/* oddly, ERROR is not defined for c++ */
#ifdef ERROR
# undef ERROR
#endif
const int ERROR = -1;
MEASAirspeed *g_dev = nullptr;
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, try the MS4525DO first */
g_dev = new MEASAirspeed(i2c_bus, I2C_ADDRESS_MS4525DO);
/* check if the MS4525DO was instantiated */
if (g_dev == nullptr)
goto fail;
/* try the MS5525DSO next if init fails */
if (OK != g_dev->Airspeed::init()) {
delete g_dev;
g_dev = new MEASAirspeed(i2c_bus, I2C_ADDRESS_MS5525DSO);
/* check if the MS5525DSO was instantiated */
if (g_dev == nullptr)
goto fail;
/* both versions failed if the init for the MS5525DSO fails, give up */
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, "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 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 'meas_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);
warnx("temperature: %d C (0x%02x)", (int)report.temperature, (unsigned) report.temperature);
}
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
meas_airspeed_usage()
{
warnx("usage: meas_airspeed command [options]");
warnx("options:");
warnx("\t-b --bus i2cbus (%d)", PX4_I2C_BUS_DEFAULT);
warnx("command:");
warnx("\tstart|stop|reset|test|info");
}
int
meas_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"))
meas_airspeed::start(i2c_bus);
/*
* Stop the driver
*/
if (!strcmp(argv[1], "stop"))
meas_airspeed::stop();
/*
* Test the driver/device.
*/
if (!strcmp(argv[1], "test"))
meas_airspeed::test();
/*
* Reset the driver.
*/
if (!strcmp(argv[1], "reset"))
meas_airspeed::reset();
/*
* Print driver information.
*/
if (!strcmp(argv[1], "info") || !strcmp(argv[1], "status"))
meas_airspeed::info();
meas_airspeed_usage();
exit(0);
}