airspeed.cpp 3.75 KB
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/**
 * @file airspeed.cpp
 * @author Simon Wilks <simon@px4.io>
 * @author Lorenz Meier <lorenz@px4.io>
 *
 */

#include <px4_platform_common/px4_config.h>
#include <drivers/device/device.h>

#include <drivers/device/i2c.h>

#include <systemlib/err.h>
#include <parameters/param.h>
#include <perf/perf_counter.h>

#include <drivers/drv_airspeed.h>
#include <drivers/drv_hrt.h>

#include <uORB/uORB.h>
#include <uORB/topics/differential_pressure.h>

#include <drivers/airspeed/airspeed.h>

Airspeed::Airspeed(int bus, int bus_frequency, int address, unsigned conversion_interval) :
	I2C(0, "Airspeed", bus, address, bus_frequency),
	_sensor_ok(false),
	_measure_interval(conversion_interval),
	_collect_phase(false),
	_diff_pres_offset(0.0f),
	_airspeed_orb_class_instance(-1),
	_class_instance(-1),
	_conversion_interval(conversion_interval),
	_sample_perf(perf_alloc(PC_ELAPSED, "aspd_read")),
	_comms_errors(perf_alloc(PC_COUNT, "aspd_com_err"))
{
}

Airspeed::~Airspeed()
{
	if (_class_instance != -1) {
		unregister_class_devname(AIRSPEED_BASE_DEVICE_PATH, _class_instance);
	}

	// free perf counters
	perf_free(_sample_perf);
	perf_free(_comms_errors);
}

int
Airspeed::init()
{
	/* do I2C init (and probe) first */
	if (I2C::init() != PX4_OK) {
		return PX4_ERROR;
	}

	/* register alternate interfaces if we have to */
	_class_instance = register_class_devname(AIRSPEED_BASE_DEVICE_PATH);

	/* advertise sensor topic, measure manually to initialize valid report */
	measure();

	return PX4_OK;
}

int
Airspeed::probe()
{
	/* on initial power up the device may need more than one retry
	   for detection. Once it is running the number of retries can
	   be reduced
	*/
	_retries = 4;
	int ret = measure();

	// drop back to 2 retries once initialised
	_retries = 2;
	return ret;
}

int
Airspeed::ioctl(device::file_t *filp, int cmd, unsigned long arg)
{
	switch (cmd) {
	case AIRSPEEDIOCSSCALE: {
			struct airspeed_scale *s = (struct airspeed_scale *)arg;
			_diff_pres_offset = s->offset_pa;
			return OK;
		}

	default:
		/* give it to the superclass */
		return I2C::ioctl(filp, cmd, arg);
	}
}