px4-firmware/apps/px4io/protocol.h

/****************************************************************************
 *
 *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
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 * 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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 * 2. Redistributions in binary form must reproduce the above copyright
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/**
 * @file PX4FMU <-> PX4IO messaging protocol.
 *
 * This initial version of the protocol is very simple; each side transmits a
 * complete update with each frame.  This avoids the sending of many small
 * messages and the corresponding complexity involved.
 */

#pragma once

#define PX4IO_CONTROL_CHANNELS	8
#define PX4IO_INPUT_CHANNELS	12
#define PX4IO_RELAY_CHANNELS	4

#pragma pack(push, 1)

/**
 * Periodic command from FMU to IO.
 */
struct px4io_command {
	uint16_t	f2i_magic;
#define F2I_MAGIC		0x636d

	uint16_t	servo_rate;
	uint16_t	output_control[PX4IO_CONTROL_CHANNELS]; /**< PWM output rate in Hz */
	bool		relay_state[PX4IO_RELAY_CHANNELS];	/**< relay states as requested by FMU */
	bool		arm_ok;					/**< FMU allows full arming */
	bool		vector_flight_mode_ok;			/**< FMU aquired a valid position lock, ready for pos control */
	bool		manual_override_ok;			/**< if true, IO performs a direct manual override */
};

/**
 * Periodic report from IO to FMU
 */
struct px4io_report {
	uint16_t	i2f_magic;
#define I2F_MAGIC		0x7570

	uint16_t	rc_channel[PX4IO_INPUT_CHANNELS];
	bool		armed;
	uint8_t		channel_count;

	uint16_t	battery_mv;
	uint16_t	adc_in;
	uint8_t		overcurrent;
};

/**
 * As-needed config message from FMU to IO
 */
struct px4io_config {
	uint16_t	f2i_config_magic;
#define F2I_CONFIG_MAGIC	 0x6366

	uint8_t		rc_map[4];	/**< channel ordering of roll, pitch, yaw, throttle */
	uint16_t	rc_min[4];	/**< min value for each channel */
	uint16_t	rc_trim[4];	/**< trim value for each channel */
	uint16_t	rc_max[4];	/**< max value for each channel */
	uint16_t	rc_rev[4];	/**< rev value for each channel */
	uint16_t	rc_dz[4];	/**< dz value for each channel */
};

/**
 * As-needed mixer data upload.
 *
 * This message adds text to the mixer text buffer; the text
 * buffer is drained as the definitions are consumed.
 */
struct px4io_mixdata {
	uint16_t	f2i_mixer_magic;
#define F2I_MIXER_MAGIC		0x6d74

	uint8_t		action;
#define F2I_MIXER_ACTION_RESET		0
#define F2I_MIXER_ACTION_APPEND		1

	char		text[0];	/* actual text size may vary */
};

/* maximum size is limited by the HX frame size */
#define F2I_MIXER_MAX_TEXT	(HX_STREAM_MAX_FRAME - sizeof(struct px4io_mixdata))

#pragma pack(pop)