/* SUMD decoder, based on PX4Firmware/src/rc/lib/rc/sumd.c from PX4Firmware modified for use in AP_HAL_* by Andrew Tridgell */ /**************************************************************************** * * 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 */ #pragma once /** * 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 since 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 */ 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);