src/main/rx/sbus_channels.h

   1 /*
   2  * This file is part of Cleanflight.
   3  *
   4  * Cleanflight is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Cleanflight is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #pragma once
  19
  20 #include <stdint.h>
  21 #include "rx/rx.h"
  22
  23 #define SBUS_MAX_CHANNEL 18
  24
  25 #define SBUS_FLAG_CHANNEL_17        (1 << 0)
  26 #define SBUS_FLAG_CHANNEL_18        (1 << 1)
  27 #define SBUS_FLAG_SIGNAL_LOSS       (1 << 2)
  28 #define SBUS_FLAG_FAILSAFE_ACTIVE   (1 << 3)
  29
  30 #define SBUS_CHANNEL_DATA_LENGTH sizeof(sbusChannels_t)
  31 #define SBUS_FRAME_SIZE (SBUS_CHANNEL_DATA_LENGTH + 2)
  32
  33 #define SBUS_FRAME_BEGIN_BYTE 0x0F
  34
  35 #define SBUS_BAUDRATE       100000
  36 #define SBUS_BAUDRATE_FAST  200000
  37
  38 #if !defined(SBUS_PORT_OPTIONS)
  39 #define SBUS_PORT_OPTIONS (SERIAL_STOPBITS_2 | SERIAL_PARITY_EVEN)
  40 #endif
  41
  42 typedef struct sbusChannels_s {
  43     // 176 bits of data (11 bits per channel * 16 channels) = 22 bytes.
  44     unsigned int chan0 : 11;
  45     unsigned int chan1 : 11;
  46     unsigned int chan2 : 11;
  47     unsigned int chan3 : 11;
  48     unsigned int chan4 : 11;
  49     unsigned int chan5 : 11;
  50     unsigned int chan6 : 11;
  51     unsigned int chan7 : 11;
  52     unsigned int chan8 : 11;
  53     unsigned int chan9 : 11;
  54     unsigned int chan10 : 11;
  55     unsigned int chan11 : 11;
  56     unsigned int chan12 : 11;
  57     unsigned int chan13 : 11;
  58     unsigned int chan14 : 11;
  59     unsigned int chan15 : 11;
  60     uint8_t flags;
  61 } __attribute__((__packed__)) sbusChannels_t;
  62
  63 typedef struct sbusFrame_s {
  64     uint8_t syncByte;
  65     sbusChannels_t channels;
  66     /**
  67      * The endByte is 0x00 on FrSky and some futaba RX's, on Some SBUS2 RX's the value indicates the telemetry byte that is sent after every 4th sbus frame.
  68      *
  69      * See https://github.com/cleanflight/cleanflight/issues/590#issuecomment-101027349
  70      * and
  71      * https://github.com/cleanflight/cleanflight/issues/590#issuecomment-101706023
  72      */
  73     uint8_t endByte;
  74 } __attribute__ ((__packed__)) sbusFrame_t;
  75
  76
  77 uint16_t sbusDecodeChannelValue(uint16_t sbusValue, bool safeValuesOnly);
  78 uint16_t sbusEncodeChannelValue(uint16_t rcValue);
  79
  80 uint8_t sbusChannelsDecode(rxRuntimeConfig_t *rxRuntimeConfig, const sbusChannels_t *channels);
  81
  82 void sbusChannelsInit(rxRuntimeConfig_t *rxRuntimeConfig);