libraries/AP_RCProtocol/AP_RCProtocol_ST24.h

   1 /*
   2  * This file is free software: you can redistribute it and/or modify it
   3  * under the terms of the GNU General Public License as published by the
   4  * Free Software Foundation, either version 3 of the License, or
   5  * (at your option) any later version.
   6  *
   7  * This file is distributed in the hope that it will be useful, but
   8  * WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  10  * See the GNU General Public License for more details.
  11  *
  12  * You should have received a copy of the GNU General Public License along
  13  * with this program.  If not, see <http://www.gnu.org/licenses/>.
  14  *
  15  * Code by Andrew Tridgell and Siddharth Bharat Purohit
  16  */
  17
  18 #pragma once
  19
  20 #include "AP_RCProtocol_config.h"
  21
  22 #if AP_RCPROTOCOL_ST24_ENABLED
  23
  24 #include "AP_RCProtocol_Backend.h"
  25 #include "SoftSerial.h"
  26
  27 #define ST24_DATA_LEN_MAX       64
  28 #define ST24_MAX_FRAMELEN   70
  29 #define ST24_STX1               0x55
  30 #define ST24_STX2               0x55
  31
  32 /* define range mapping here, -+100% -> 1000..2000 */
  33 #define ST24_RANGE_MIN 0.0f
  34 #define ST24_RANGE_MAX 4096.0f
  35
  36 #define ST24_TARGET_MIN 1000.0f
  37 #define ST24_TARGET_MAX 2000.0f
  38
  39 /* pre-calculate the floating point stuff as far as possible at compile time */
  40 #define ST24_SCALE_FACTOR ((ST24_TARGET_MAX - ST24_TARGET_MIN) / (ST24_RANGE_MAX - ST24_RANGE_MIN))
  41 #define ST24_SCALE_OFFSET (int)(ST24_TARGET_MIN - (ST24_SCALE_FACTOR * ST24_RANGE_MIN + 0.5f))
  42
  43 class AP_RCProtocol_ST24 : public AP_RCProtocol_Backend {
  44 public:
  45     AP_RCProtocol_ST24(AP_RCProtocol &_frontend) : AP_RCProtocol_Backend(_frontend) {}
  46     void process_pulse(uint32_t width_s0, uint32_t width_s1) override;
  47     void process_byte(uint8_t byte, uint32_t baudrate) override;
  48 private:
  49     void _process_byte(uint8_t byte);
  50     static uint8_t st24_crc8(uint8_t *ptr, uint8_t len);
  51     enum ST24_PACKET_TYPE {
  52         ST24_PACKET_TYPE_CHANNELDATA12 = 0,
  53         ST24_PACKET_TYPE_CHANNELDATA24,
  54         ST24_PACKET_TYPE_TRANSMITTERGPSDATA
  55     };
  56
  57 #pragma pack(push, 1)
  58     typedef struct {
  59         uint8_t header1;                        ///< 0x55 for a valid packet
  60         uint8_t header2;                        ///< 0x55 for a valid packet
  61         uint8_t length;                         ///< length includes type, data, and crc = sizeof(type)+sizeof(data[payload_len])+sizeof(crc8)
  62         uint8_t type;                           ///< from enum ST24_PACKET_TYPE
  63         uint8_t st24_data[ST24_DATA_LEN_MAX];
  64         uint8_t crc8;                           ///< crc8 checksum, calculated by st24_common_crc8 and including fields length, type and st24_data
  65     } ReceiverFcPacket;
  66
  67     /**
  68      * RC Channel data (12 channels).
  69      *
  70      * This is incoming from the ST24
  71      */
  72     typedef struct {
  73         uint16_t t;                     ///< packet counter or clock
  74         uint8_t rssi;                   ///< signal strength
  75         uint8_t packet_count;           ///< Number of UART packets sent since reception of last RF frame (this tells something about age / rate)
  76         uint8_t channel[18];            ///< channel data, 12 channels (12 bit numbers)
  77     } ChannelData12;
  78
  79     /**
  80      * RC Channel data (12 channels).
  81      *
  82      */
  83     typedef struct {
  84         uint16_t t;                     ///< packet counter or clock
  85         uint8_t rssi;                   ///< signal strength
  86         uint8_t packet_count;           ///< Number of UART packets sent since reception of last RF frame (this tells something about age / rate)
  87         uint8_t channel[36];            ///< channel data, 24 channels (12 bit numbers)
  88     } ChannelData24;
  89
  90     /**
  91      * Telemetry packet
  92      *
  93      * This is outgoing to the ST24
  94      *
  95      * imuStatus:
  96      * 8 bit total
  97      * bits 0-2 for status
  98      * - value 0 is FAILED
  99      * - value 1 is INITIALIZING
 100      * - value 2 is RUNNING
 101      * - values 3 through 7 are reserved
 102      * bits 3-7 are status for sensors (0 or 1)
 103      * - mpu6050
 104      * - accelerometer
 105      * - primary gyro x
 106      * - primary gyro y
 107      * - primary gyro z
 108      *
 109      * pressCompassStatus
 110      * 8 bit total
 111      * bits 0-3 for compass status
 112      * - value 0 is FAILED
 113      * - value 1 is INITIALIZING
 114      * - value 2 is RUNNING
 115      * - value 3 - 15 are reserved
 116      * bits 4-7 for pressure status
 117      * - value 0 is FAILED
 118      * - value 1 is INITIALIZING
 119      * - value 2 is RUNNING
 120      * - value 3 - 15 are reserved
 121      *
 122      */
 123     typedef struct {
 124         uint16_t t;                     ///< packet counter or clock
 125         int32_t lat;                    ///< lattitude (degrees)        +/- 90 deg
 126         int32_t lon;                    ///< longitude (degrees)        +/- 180 deg
 127         int32_t alt;                    ///< 0.01m resolution, altitude (meters)
 128         int16_t vx, vy, vz;             ///< velocity 0.01m res, +/-320.00 North-East- Down
 129         uint8_t nsat;                   ///<number of satellites
 130         uint8_t voltage;                ///< 25.4V      voltage = 5 + 255*0.1 = 30.5V, min=5V
 131         uint8_t current;                ///< 0.5A resolution
 132         int16_t roll, pitch, yaw;       ///< 0.01 degree resolution
 133         uint8_t motorStatus;            ///< 1 bit per motor for status 1=good, 0= fail
 134         uint8_t imuStatus;              ///< inertial measurement unit status
 135         uint8_t pressCompassStatus;     ///< baro / compass status
 136     } TelemetryData;
 137
 138 #pragma pack(pop)
 139
 140     enum ST24_DECODE_STATE {
 141         ST24_DECODE_STATE_UNSYNCED = 0,
 142         ST24_DECODE_STATE_GOT_STX1,
 143         ST24_DECODE_STATE_GOT_STX2,
 144         ST24_DECODE_STATE_GOT_LEN,
 145         ST24_DECODE_STATE_GOT_TYPE,
 146         ST24_DECODE_STATE_GOT_DATA
 147     };
 148
 149     enum ST24_DECODE_STATE _decode_state = ST24_DECODE_STATE_UNSYNCED;
 150     uint8_t _rxlen;
 151
 152     ReceiverFcPacket _rxpacket;
 153
 154     SoftSerial ss{115200, SoftSerial::SERIAL_CONFIG_8N1};
 155 };
 156
 157 #endif  // AP_RCPROTOCOL_ST24_ENABLED