sumd.cpp File Reference

#include <stdbool.h>
#include <stdio.h>
#include "sumd.h"
#include "common_rc.h"

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Macros
#define	SUMD_RANGE_MIN   0.0f
#define	SUMD_RANGE_MAX   4096.0f
#define	SUMD_TARGET_MIN   1000.0f
#define	SUMD_TARGET_MAX   2000.0f
#define	SUMD_SCALE_FACTOR   ((SUMD_TARGET_MAX - SUMD_TARGET_MIN) / (SUMD_RANGE_MAX - SUMD_RANGE_MIN))
#define	SUMD_SCALE_OFFSET   (int)(SUMD_TARGET_MIN - (SUMD_SCALE_FACTOR * SUMD_RANGE_MIN + 0.5f))

Enumerations
enum	SUMD_DECODE_STATE {   SUMD_DECODE_STATE_UNSYNCED = 0, SUMD_DECODE_STATE_GOT_HEADER, SUMD_DECODE_STATE_GOT_STATE, SUMD_DECODE_STATE_GOT_LEN,   SUMD_DECODE_STATE_GOT_DATA, SUMD_DECODE_STATE_GOT_CRC, SUMD_DECODE_STATE_GOT_CRC16_BYTE_1, SUMD_DECODE_STATE_GOT_CRC16_BYTE_2 }

Functions
uint16_t	sumd_crc16 (uint16_t crc, uint8_t value)
	CRC16 implementation for SUMD protocol. More...
uint8_t	sumd_crc8 (uint8_t crc, uint8_t value)
	CRC8 implementation for SUMH protocol. More...
int	sumd_decode (uint8_t byte, uint8_t *rssi, uint8_t *rx_count, uint16_t *channel_count, uint16_t *channels, uint16_t max_chan_count, bool *failsafe)
	Decoder for SUMD/SUMH protocol. More...

Variables
uint8_t	_crc8 = 0x00
uint16_t	_crc16 = 0x0000
bool	_sumd = true
bool	_crcOK = false
bool	_debug = false
static enum SUMD_DECODE_STATE	_decode_state = SUMD_DECODE_STATE_UNSYNCED
static uint8_t	_rxlen
static ReceiverFcPacketHoTT &	_rxpacket = rc_decode_buf._hottrxpacket

Macro Definition Documentation

SUMD_RANGE_MAX

#define SUMD_RANGE_MAX   4096.0f

Definition at line 79 of file sumd.cpp.

SUMD_RANGE_MIN

#define SUMD_RANGE_MIN   0.0f

Definition at line 78 of file sumd.cpp.

SUMD_SCALE_FACTOR

#define SUMD_SCALE_FACTOR   ((SUMD_TARGET_MAX - SUMD_TARGET_MIN) / (SUMD_RANGE_MAX - SUMD_RANGE_MIN))

Definition at line 85 of file sumd.cpp.

SUMD_SCALE_OFFSET

#define SUMD_SCALE_OFFSET   (int)(SUMD_TARGET_MIN - (SUMD_SCALE_FACTOR * SUMD_RANGE_MIN + 0.5f))

Definition at line 86 of file sumd.cpp.

SUMD_TARGET_MAX

#define SUMD_TARGET_MAX   2000.0f

Definition at line 82 of file sumd.cpp.

SUMD_TARGET_MIN

#define SUMD_TARGET_MIN   1000.0f

Definition at line 81 of file sumd.cpp.

Enumeration Type Documentation

SUMD_DECODE_STATE

enum SUMD_DECODE_STATE

Enumerator
SUMD_DECODE_STATE_UNSYNCED
SUMD_DECODE_STATE_GOT_HEADER
SUMD_DECODE_STATE_GOT_STATE
SUMD_DECODE_STATE_GOT_LEN
SUMD_DECODE_STATE_GOT_DATA
SUMD_DECODE_STATE_GOT_CRC
SUMD_DECODE_STATE_GOT_CRC16_BYTE_1
SUMD_DECODE_STATE_GOT_CRC16_BYTE_2

Definition at line 47 of file sumd.cpp.

Function Documentation

sumd_crc16()

uint16_t sumd_crc16	(	uint16_t	crc,
		uint8_t	value
	)

CRC16 implementation for SUMD protocol.

Parameters

crc	Initial CRC Value
value	to accumulate in the checksum

Returns

the checksum

Definition at line 93 of file sumd.cpp.

Referenced by sumd_decode().

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sumd_crc8()

uint8_t sumd_crc8	(	uint8_t	crc,
		uint8_t	value
	)

CRC8 implementation for SUMH protocol.

Parameters

crc	Initial CRC Value
value	to accumulate in the checksum

Returns

the checksum

Definition at line 105 of file sumd.cpp.

Referenced by sumd_decode().

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sumd_decode()

int sumd_decode	(	uint8_t	byte,
		uint8_t *	rssi,
		uint8_t *	rx_count,
		uint16_t *	channel_count,
		uint16_t *	channels,
		uint16_t	max_chan_count,
		bool *	failsafe
	)

Decoder for SUMD/SUMH protocol.

Parameters

byte	current char to read
rssi	pointer to a byte where the RSSI value is written back to
rx_count	pointer to a byte where the receive count of packets signce last wireless frame is written back to
channels	pointer to a datastructure of size max_chan_count where channel values (12 bit) are written back to
max_chan_count	maximum channels to decode - if more channels are decoded, the last n are skipped and success (0) is returned
failsafe	pointer to a boolean where the decoded failsafe flag is written back to

Returns

0 for success (a decoded packet), 1 for no packet yet (accumulating), 2 for unknown packet, 3 for out of sync, 4 for checksum error

Definition at line 111 of file sumd.cpp.

References _crc16, _crc8, _crcOK, _debug, _decode_state, _rxlen, _sumd, ReceiverFcPacketHoTT::crc16_high, ReceiverFcPacketHoTT::crc16_low, ReceiverFcPacketHoTT::crc8, ReceiverFcPacketHoTT::header, ReceiverFcPacketHoTT::length, ReceiverFcPacketHoTT::status, sumd_crc16(), sumd_crc8(), ReceiverFcPacketHoTT::sumd_data, SUMD_DECODE_STATE_GOT_CRC, SUMD_DECODE_STATE_GOT_CRC16_BYTE_1, SUMD_DECODE_STATE_GOT_CRC16_BYTE_2, SUMD_DECODE_STATE_GOT_DATA, SUMD_DECODE_STATE_GOT_HEADER, SUMD_DECODE_STATE_GOT_LEN, SUMD_DECODE_STATE_GOT_STATE, SUMD_DECODE_STATE_UNSYNCED, SUMD_HEADER_ID, SUMD_ID_FAILSAFE, SUMD_ID_SUMD, SUMD_ID_SUMH, SUMD_MAX_CHANNELS, and ReceiverFcPacketHoTT::telemetry.

Referenced by RCInput::cycle(), dsm_port_input(), and RCTest::sumdTest().

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Variable Documentation

_crc16

uint16_t _crc16 = 0x0000

Definition at line 71 of file sumd.cpp.

Referenced by sumd_decode().

_crc8

uint8_t _crc8 = 0x00

Definition at line 70 of file sumd.cpp.

Referenced by sumd_decode().

_crcOK

bool _crcOK = false

Definition at line 73 of file sumd.cpp.

Referenced by sumd_decode().

_debug

bool _debug = false

Definition at line 74 of file sumd.cpp.

Referenced by sumd_decode().

_decode_state

enum SUMD_DECODE_STATE _decode_state = SUMD_DECODE_STATE_UNSYNCED

static

Definition at line 88 of file sumd.cpp.

Referenced by sumd_decode().

_rxlen

uint8_t _rxlen

static

Definition at line 89 of file sumd.cpp.

Referenced by sumd_decode().

_rxpacket

ReceiverFcPacketHoTT& _rxpacket = rc_decode_buf._hottrxpacket

static

Definition at line 91 of file sumd.cpp.

_sumd

bool _sumd = true

Definition at line 72 of file sumd.cpp.

Referenced by sumd_decode().