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https://gitee.com/mirrors_PX4/PX4-Autopilot.git
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Lorenz Meier
86 lines
3.3 KiB
C
86 lines
3.3 KiB
C
/****************************************************************************
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*
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* Copyright (c) 2012-2015 PX4 Development Team. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name PX4 nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/**
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* @file sbus.h
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*
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* RC protocol definition for S.BUS
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*
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* @author Lorenz Meier <lorenz@px4.io>
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*/
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#pragma once
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#include <stdint.h>
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#include <stdbool.h>
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__BEGIN_DECLS
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#define SBUS_FRAME_SIZE 25
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#define SBUS_BUFFER_SIZE (SBUS_FRAME_SIZE + SBUS_FRAME_SIZE / 2)
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__EXPORT int sbus_init(const char *device, bool singlewire);
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/**
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* Parse serial bytes on the S.BUS bus
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*
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* The S.bus protocol doesn't provide reliable framing,
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* so we detect frame boundaries by the inter-frame delay.
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*
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* The minimum frame spacing is 7ms; with 25 bytes at 100000bps
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* frame transmission time is ~2ms.
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*
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* If an interval of more than 4ms (7 ms frame spacing plus margin)
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* passes between calls, the first byte we read will be the first
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* byte of a frame.
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*
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* In the case where byte(s) are dropped from a frame, this also
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* provides a degree of protection. Of course, it would be better
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* if we didn't drop bytes...
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*/
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__EXPORT int sbus_config(int sbus_fd, bool singlewire);
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__EXPORT bool sbus_input(int sbus_fd, uint16_t *values, uint16_t *num_values, bool *sbus_failsafe,
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bool *sbus_frame_drop,
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uint16_t max_channels);
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__EXPORT bool sbus_parse(uint64_t now, uint8_t *frame, unsigned len, uint16_t *values,
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uint16_t *num_values, bool *sbus_failsafe, bool *sbus_frame_drop, unsigned *frame_drops, uint16_t max_channels);
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__EXPORT void sbus1_output(int sbus_fd, uint16_t *values, uint16_t num_values);
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__EXPORT void sbus2_output(int sbus_fd, uint16_t *values, uint16_t num_values);
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/**
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* The number of incomplete frames we encountered
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*/
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__EXPORT unsigned sbus_dropped_frames(void);
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__END_DECLS
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