dsm.h

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/**
 * @file dsm.h
 *
 * RC protocol definition for Spektrum RC
 *
 * @author Lorenz Meier <lorenz@px4.io>
 */

#pragma once

#include <stdint.h>

#include <px4_platform_common/px4_config.h>
#include <px4_platform_common/defines.h>

__BEGIN_DECLS

#define DSM_FRAME_SIZE      16      /**< DSM frame size in bytes */
#define DSM_FRAME_CHANNELS  7       /**< Max supported DSM channels per frame */
#define DSM_MAX_CHANNEL_COUNT   18  /**< Max channel count of any DSM RC */
#define DSM_BUFFER_SIZE     (DSM_FRAME_SIZE + DSM_FRAME_SIZE / 2)


#pragma pack(push, 1)
typedef   uint8_t dsm_frame_t[DSM_BUFFER_SIZE]; /**< DSM dsm frame receive buffer */
typedef   uint8_t dsm_buf_t[DSM_FRAME_SIZE * 2]; // Define working buffer

typedef  struct dsm_decode_t {
    dsm_frame_t frame;
    dsm_buf_t buf;
} dsm_decode_t;

#pragma pack(pop)

__EXPORT int    dsm_init(const char *device);
__EXPORT void   dsm_deinit(void);
__EXPORT void   dsm_proto_init(void);
__EXPORT int    dsm_config(int dsm_fd);
__EXPORT bool   dsm_input(int dsm_fd, uint16_t *values, uint16_t *num_values, bool *dsm_11_bit, uint8_t *n_bytes,
              uint8_t **bytes, int8_t *rssi, unsigned max_values);

__EXPORT bool   dsm_parse(const uint64_t now, const uint8_t *frame, const unsigned len, uint16_t *values,
              uint16_t *num_values, bool *dsm_11_bit, unsigned *frame_drops, int8_t *rssi_percent, uint16_t max_channels);

#ifdef SPEKTRUM_POWER
__EXPORT void   dsm_bind(uint16_t cmd, int pulses);
#endif

enum DSM_CMD {                          /* DSM bind states */
    DSM_CMD_BIND_POWER_DOWN = 0,
    DSM_CMD_BIND_POWER_UP,
    DSM_CMD_BIND_SET_RX_OUT,
    DSM_CMD_BIND_SEND_PULSES,
    DSM_CMD_BIND_REINIT_UART
};

#define DSM2_BIND_PULSES 3  /* DSM_BIND_START parameter, pulses required to start dsm2 pairing */
#define DSMX_BIND_PULSES 7  /* DSM_BIND_START parameter, pulses required to start dsmx pairing */
#define DSMX8_BIND_PULSES 9 /* DSM_BIND_START parameter, pulses required to start 8 or more channel dsmx pairing */

__END_DECLS