px4-firmware/apps/drivers/drv_accel.h

/****************************************************************************
 *
 *   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
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 * 1. Redistributions of source code must retain the above copyright
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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/**
 * @file Accelerometer driver interface.
 */

#ifndef _DRV_ACCEL_H
#define _DRV_ACCEL_H

#include <stdint.h>
#include <sys/ioctl.h>

#include "drv_sensor.h"
#include "drv_orb_dev.h"

#define ACCEL_DEVICE_PATH	"/dev/accel"

/**
 * accel report structure.  Reads from the device must be in multiples of this
 * structure.
 */
struct accel_report {
	uint64_t timestamp;
	float x;		/**< acceleration in the NED X board axis in m/s^2 */
	float y;		/**< acceleration in the NED Y board axis in m/s^2 */
	float z;		/**< acceleration in the NED Z board axis in m/s^2 */
	float temperature;	/**< temperature in degrees celsius */
	float range_m_s2;	/**< range in m/s^2 (+- this value) */
	float scaling;

	int16_t x_raw;
	int16_t y_raw;
	int16_t z_raw;
	int16_t temperature_raw;
};

/** accel scaling factors; Vout = (Vin * Vscale) + Voffset */
struct accel_scale {
	float	x_offset;
	float	x_scale;
	float	y_offset;
	float	y_scale;
	float	z_offset;
	float	z_scale;
};

/*
 * ObjDev tag for raw accelerometer data.
 */
ORB_DECLARE(sensor_accel);

/*
 * ioctl() definitions
 *
 * Accelerometer drivers also implement the generic sensor driver 
 * interfaces from drv_sensor.h
 */

#define _ACCELIOCBASE		(0x2100)
#define _ACCELIOC(_n)		(_IOC(_ACCELIOCBASE, _n))


/** set the accel internal sample rate to at least (arg) Hz */
#define ACCELIOCSSAMPLERATE	_ACCELIOC(0)

/** return the accel internal sample rate in Hz */
#define ACCELIOCGSAMPLERATE	_ACCELIOC(1)

/** set the accel internal lowpass filter to no lower than (arg) Hz */
#define ACCELIOCSLOWPASS	_ACCELIOC(2)

/** return the accel internal lowpass filter in Hz */
#define ACCELIOCGLOWPASS	_ACCELIOC(3)

/** set the accel scaling constants to the structure pointed to by (arg) */
#define ACCELIOCSSCALE		_ACCELIOC(5)

/** get the accel scaling constants into the structure pointed to by (arg) */
#define ACCELIOCGSCALE		_ACCELIOC(6)

/** set the accel measurement range to handle at least (arg) g */
#define ACCELIOCSRANGE		_ACCELIOC(7)

/** get the current accel measurement range in g */
#define ACCELIOCGRANGE		_ACCELIOC(8)

#endif /* _DRV_ACCEL_H */