Line data    Source code

       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_DSM_ENABLED
      23             : 
      24             : #include "AP_RCProtocol_Backend.h"
      25             : 
      26             : #include "SoftSerial.h"
      27             : 
      28             : #define AP_DSM_MAX_CHANNELS 12
      29             : 
      30             : class AP_RCProtocol_DSM : public AP_RCProtocol_Backend {
      31             : public:
      32        2094 :     AP_RCProtocol_DSM(AP_RCProtocol &_frontend) : AP_RCProtocol_Backend(_frontend) {}
      33             :     void process_pulse(uint32_t width_s0, uint32_t width_s1) override;
      34             :     void process_byte(uint8_t byte, uint32_t baudrate) override;
      35             :     void start_bind(void) override;
      36             :     void update(void) override;
      37             : 
      38             : private:
      39             :     void _process_byte(uint32_t timestamp_ms, uint8_t byte);
      40             :     void dsm_decode();
      41             :     bool dsm_decode_channel(uint16_t raw, unsigned shift, unsigned *channel, unsigned *value);
      42             :     void dsm_guess_format(bool reset, const uint8_t dsm_frame[16], unsigned frame_channels);
      43             :     bool dsm_parse_byte(uint32_t frame_time_ms, uint8_t b, uint16_t *values,
      44             :                         uint16_t *num_values, uint16_t max_channels);
      45             :     bool dsm_decode(uint32_t frame_time_ms, const uint8_t dsm_frame[16],
      46             :                     uint16_t *values, uint16_t *num_values, uint16_t max_values);
      47             : 
      48             :     /**< Channel resolution, 0=unknown, 10=10 bit, 11=11 bit */
      49             :     uint8_t channel_shift;
      50             : 
      51             :     // format guessing state
      52             :     uint32_t    cs10;
      53             :     uint32_t    cs11;
      54             :     uint32_t samples;
      55             : 
      56             :     // bind state machine
      57             :     enum {
      58             :         BIND_STATE_NONE,
      59             :         BIND_STATE1,
      60             :         BIND_STATE2,
      61             :         BIND_STATE3,
      62             :         BIND_STATE4,
      63             :     } bind_state;
      64             :     uint32_t bind_last_ms;
      65             :     uint32_t bind_mode_saved;
      66             : 
      67             :     uint16_t last_values[AP_DSM_MAX_CHANNELS];
      68             : 
      69             :     struct {
      70             :         uint8_t buf[16];
      71             :         uint8_t ofs;
      72             :     } byte_input;
      73             : 
      74             :     enum DSM_DECODE_STATE {
      75             :         DSM_DECODE_STATE_DESYNC = 0,
      76             :         DSM_DECODE_STATE_SYNC
      77             :     } dsm_decode_state;
      78             : 
      79             :     uint32_t last_frame_time_ms;
      80             :     uint32_t last_rx_time_ms;
      81             :     uint16_t chan_count;
      82             : 
      83             :     SoftSerial ss{115200, SoftSerial::SERIAL_CONFIG_8N1};
      84             : };
      85             : 
      86             : #endif  // AP_RCPROTOCOL_DSM_ENABLED