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/****************************************************************************
*
* Copyright (c) 2015 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
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file sumd.h
*
* RC protocol definition for Graupner HoTT transmitter
*
* @author Marco Bauer <marco@wtns.de>
*/
#pragma once
#include <stdint.h>
__BEGIN_DECLS
#define SUMD_MAX_CHANNELS 32
#define SUMD_HEADER_LENGTH 3
#define SUMD_HEADER_ID 0xA8
#define SUMD_ID_SUMH 0x00
#define SUMD_ID_SUMD 0x01
#define SUMD_ID_FAILSAFE 0x81
#pragma pack(push, 1)
typedef struct {
uint8_t header; ///< 0xA8 for a valid packet
uint8_t status; ///< 0x01 valid and live SUMD data frame / 0x00 = SUMH / 0x81 = Failsafe
uint8_t length; ///< Channels
uint8_t sumd_data[SUMD_MAX_CHANNELS*2]; ///< ChannelData (High Byte/ Low Byte)
uint8_t crc16_high; ///< High Byte of 16 Bit CRC
uint8_t crc16_low; ///< Low Byte of 16 Bit CRC
uint8_t telemetry; ///< Telemetry request
uint8_t crc8; ///< SUMH CRC8
} ReceiverFcPacketHoTT;
#pragma pack(pop)
/**
* CRC16 implementation for SUMD protocol
*
* @param crc Initial CRC Value
* @param value to accumulate in the checksum
* @return the checksum
*/
uint16_t sumd_crc16(uint16_t crc, uint8_t value);
/**
* CRC8 implementation for SUMH protocol
*
* @param crc Initial CRC Value
* @param value to accumulate in the checksum
* @return the checksum
*/
uint8_t sumd_crc8(uint8_t crc, uint8_t value);
/**
* Decoder for SUMD/SUMH protocol
*
* @param byte current char to read
* @param rssi pointer to a byte where the RSSI value is written back to
* @param rx_count pointer to a byte where the receive count of packets signce last wireless frame is written back to
* @param channels pointer to a datastructure of size max_chan_count where channel values (12 bit) are written back to
* @param max_chan_count maximum channels to decode - if more channels are decoded, the last n are skipped and success (0) is returned
* @return 0 for success (a decoded packet), 1 for no packet yet (accumulating), 2 for unknown packet, 3 for out of sync, 4 for checksum error
*/
/*
__EXPORT int sumd_decode(uint8_t byte, uint8_t *rssi, uint8_t *rx_count, uint16_t *channel_count,
uint16_t *channels, uint16_t max_chan_count);
*/
int sumd_decode(uint8_t byte, uint8_t *rssi, uint8_t *rx_count, uint16_t *channel_count,
uint16_t *channels, uint16_t max_chan_count);
__END_DECLS
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