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96 lines
3.1 KiB
C
96 lines
3.1 KiB
C
/**
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******************************************************************************
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* @addtogroup PIOS PIOS Core hardware abstraction layer
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* @{
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* @addtogroup PIOS_SRXL Multiplex SRXL receiver functions
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* @brief Code to read Multiplex SRXL receiver serial stream
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* @{
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*
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* @file pios_srxl_priv.h
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* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2015.
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* @brief Code to read Multiplex SRXL receiver serial stream
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* @see The GNU Public License (GPL) Version 3
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*
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*****************************************************************************/
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/*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifndef PIOS_SRXL_PRIV_H
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#define PIOS_SRXL_PRIV_H
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#include <pios.h>
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#include <pios_stm32.h>
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#include <pios_usart_priv.h>
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/*
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* Multiplex SRXL serial port settings:
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* 115200bps inverted serial stream, 8 bits, no parity, 1 stop bits
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* frame period is 14ms (FastResponse ON) or 21ms (FastResponse OFF)
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*
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* Frame structure:
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* 1 byte - start and version
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* 0xa1 (v1 12-channels)
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* 0xa2 (v2 16-channels)
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* 24/32 bytes - channel data (4 + 12 bit/channel, 12/16 channels, MSB first)
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* 16 bits per channel. 4 first reserved/not used. 12 bits channel data in
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* 4095 steps, 0x000(800µs) - 0x800(1500µs) - 0xfff(2200µs)
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* 2 bytes checksum (calculated over all bytes including start and version)
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*
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* Checksum calculation:
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* u16 CRC16(u16 crc, u8 value) {
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* u8 i;
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* crc = crc ^ (s16)value << 8;
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* for(i = 0; i < 8; i++) {
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* if(crc & 0x8000) {
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* crc = crc << 1 ^ 0x1021;
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* } else {
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* crc = crc << 1;
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* }
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* }
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* return crc;
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* }
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*/
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#define SRXL_V1_HEADER 0xa1
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#define SRXL_V2_HEADER 0xa2
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#define SRXL_HEADER_LENGTH 1
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#define SRXL_CHECKSUM_LENGTH 2
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#define SRXL_V1_CHANNEL_DATA_BYTES (12 * 2)
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#define SRXL_V2_CHANNEL_DATA_BYTES (16 * 2)
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#define SRXL_FRAME_LENGTH (SRXL_HEADER_LENGTH + SRXL_V2_CHANNEL_DATA_BYTES + SRXL_CHECKSUM_LENGTH)
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/*
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* Multiplex SRXL protocol provides 16 proportional channels.
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* Do not change unless driver code is updated accordingly.
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*/
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#if (PIOS_SRXL_NUM_INPUTS != 16)
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#error "Multiplex SRXL protocol provides 16 proportional channels."
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#endif
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extern const struct pios_rcvr_driver pios_srxl_rcvr_driver;
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extern int32_t PIOS_SRXL_Init(uint32_t *srxl_id,
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const struct pios_com_driver *driver,
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uint32_t lower_id);
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#endif /* PIOS_SRXL_PRIV_H */
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/**
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* @}
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* @}
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*/
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