File syn_msp.h¶

FileList > proto > syn_msp.h

Zero-Heap MSP (MultiWii Serial Protocol v1/v2) Encoder & Decoder. More...

#include "syntropic/common/syn_defs.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Classes¶

Type	Name
struct	SYN_MSP_Frame
struct	SYN_MSP_Parser

Public Types¶

Type	Name
enum	SYN_MSP_Cmd

Public Functions¶

Type	Name
SYN_Status	syn_msp_encode_response (uint8_t cmd, const uint8_t * payload, uint8_t len, uint8_t * buf_out, size_t buf_size, size_t * out_len) Encode an MSP response frame into raw serial bytes buffer.
SYN_Status	syn_msp_init (SYN_MSP_Parser * parser) Initialize MSP parser instance.
SYN_Status	syn_msp_parse_byte (SYN_MSP_Parser * parser, uint8_t byte, SYN_MSP_Frame * frame) Process incoming byte from serial stream.

Macros¶

Type	Name
define	SYN_MSP_ERR_CHAR `'!'`
define	SYN_MSP_HEADER_CHAR `'$'`
define	SYN_MSP_MAX_PAYLOAD `64U`
define	SYN_MSP_REQ_CHAR `'<'`
define	SYN_MSP_RESP_CHAR `'>'`
define	SYN_MSP_V1_CHAR `'[M](syn__x25519_8c.md#function-m)'`

Detailed Description¶

MSP Specifications: * Frame Format: $M + [Direction] + [Size] + [Command] + [Payload...] + [Checksum] * Direction: < (Inbound Request), > (Outbound Response), ! (Error Response). * Checksum: XOR sum over Size ^ Command ^ Payload[0] ^ ... ^ Payload[N-1]. * Common Commands: * 101: MSP_STATUS (Cycle time, I2C errors, sensors active, flight mode flags). * 102: MSP_RAW_IMU (Gyro X/Y/Z, Accel X/Y/Z, Mag X/Y/Z). * 108: MSP_ATTITUDE (Roll 10x deg, Pitch 10x deg, Yaw deg). * 109: MSP_ALTITUDE (Estimated altitude in cm & variometer rate). * 130: MSP_BATTERY_STATE (Cell count, capacity mAh, voltage 0.1V, current 0.01A).

Public Types Documentation¶

enum SYN_MSP_Cmd¶

enum SYN_MSP_Cmd {
    SYN_MSP_API_VERSION = 1U,
    SYN_MSP_FC_VARIANT = 2U,
    SYN_MSP_STATUS = 101U,
    SYN_MSP_RAW_IMU = 102U,
    SYN_MSP_ATTITUDE = 108U,
    SYN_MSP_ALTITUDE = 109U,
    SYN_MSP_BATTERY_STATE = 130U
};

Common MSP Command IDs.

Public Functions Documentation¶

function syn_msp_encode_response¶

Encode an MSP response frame into raw serial bytes buffer.

SYN_Status syn_msp_encode_response (
    uint8_t cmd,
    const uint8_t * payload,
    uint8_t len,
    uint8_t * buf_out,
    size_t buf_size,
    size_t * out_len
)

Parameters:

cmd Command ID.
payload Pointer to payload buffer (or NULL if 0 length).
len Payload length in bytes.
buf_out Output buffer (must hold at least len + 6 bytes).
buf_size Capacity of buf_out in bytes.
out_len Pointer to receive total generated frame length in bytes.

Returns:

SYN_OK on success.

function syn_msp_init¶

Initialize MSP parser instance.

SYN_Status syn_msp_init (
    SYN_MSP_Parser * parser
)

Parameters:

parser Pointer to parser struct.

Returns:

SYN_OK on success.

function syn_msp_parse_byte¶

Process incoming byte from serial stream.

SYN_Status syn_msp_parse_byte (
    SYN_MSP_Parser * parser,
    uint8_t byte,
    SYN_MSP_Frame * frame
)

Parameters:

parser Pointer to parser struct.
byte Incoming serial byte.
frame Pointer to destination frame (populated on complete valid frame).

Returns:

SYN_OK on complete frame, SYN_BUSY if byte accepted but frame incomplete, SYN_ERROR on checksum failure.

Macro Definition Documentation¶

define SYN_MSP_ERR_CHAR¶

#define SYN_MSP_ERR_CHAR `'!'`

MSP direction character for error '!'

define SYN_MSP_HEADER_CHAR¶

#define SYN_MSP_HEADER_CHAR `'$'`

MSP preamble start character '$'

define SYN_MSP_MAX_PAYLOAD¶

#define SYN_MSP_MAX_PAYLOAD `64U`

Maximum MSP v1 payload byte length

define SYN_MSP_REQ_CHAR¶

#define SYN_MSP_REQ_CHAR `'<'`

MSP direction character for request '<'

define SYN_MSP_RESP_CHAR¶

#define SYN_MSP_RESP_CHAR `'>'`

MSP direction character for response '>'

define SYN_MSP_V1_CHAR¶

#define SYN_MSP_V1_CHAR `' M '`

MSP v1 protocol identifier 'M'

The documentation for this class was generated from the following file src/syntropic/proto/syn_msp.h