st24.cpp File Reference

#include <stdio.h>
#include <stdint.h>
#include "st24.h"

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Classes
struct	ReceiverFcPacket
struct	ChannelData12
struct	ChannelData24
struct	TelemetryData

Macros
#define	ST24_DATA_LEN_MAX   64
#define	ST24_STX1   0x55
#define	ST24_STX2   0x55
#define	ST24_RANGE_MIN   0.0f
#define	ST24_RANGE_MAX   4096.0f
#define	ST24_TARGET_MIN   1000.0f
#define	ST24_TARGET_MAX   2000.0f
#define	ST24_SCALE_FACTOR   ((ST24_TARGET_MAX - ST24_TARGET_MIN) / (ST24_RANGE_MAX - ST24_RANGE_MIN))
#define	ST24_SCALE_OFFSET   (int)(ST24_TARGET_MIN - (ST24_SCALE_FACTOR * ST24_RANGE_MIN + 0.5f))

Enumerations
enum	ST24_PACKET_TYPE { ST24_PACKET_TYPE_CHANNELDATA12 = 0, ST24_PACKET_TYPE_CHANNELDATA24, ST24_PACKET_TYPE_TRANSMITTERGPSDATA }
enum	ST24_DECODE_STATE {   ST24_DECODE_STATE_UNSYNCED = 0, ST24_DECODE_STATE_GOT_STX1, ST24_DECODE_STATE_GOT_STX2, ST24_DECODE_STATE_GOT_LEN,   ST24_DECODE_STATE_GOT_TYPE, ST24_DECODE_STATE_GOT_DATA }

Functions
static uint8_t	st24_common_crc8 (uint8_t *ptr, uint8_t len)
int	st24_decode (uint8_t byte, uint8_t *rssi, uint8_t *rx_count, uint16_t *channel_count, uint16_t *channels, uint16_t max_chan_count)

Variables
static enum ST24_DECODE_STATE	_decode_state = ST24_DECODE_STATE_UNSYNCED
static uint8_t	_rxlen
static ReceiverFcPacket	_rxpacket

Macro Definition Documentation

ST24_DATA_LEN_MAX

#define ST24_DATA_LEN_MAX   64

Definition at line 50 of file st24.cpp.

ST24_RANGE_MAX

#define ST24_RANGE_MAX   4096.0f

Definition at line 154 of file st24.cpp.

ST24_RANGE_MIN

#define ST24_RANGE_MIN   0.0f

Definition at line 153 of file st24.cpp.

ST24_SCALE_FACTOR

#define ST24_SCALE_FACTOR   ((ST24_TARGET_MAX - ST24_TARGET_MIN) / (ST24_RANGE_MAX - ST24_RANGE_MIN))

Definition at line 160 of file st24.cpp.

Referenced by st24_decode().

ST24_SCALE_OFFSET

#define ST24_SCALE_OFFSET   (int)(ST24_TARGET_MIN - (ST24_SCALE_FACTOR * ST24_RANGE_MIN + 0.5f))

Definition at line 161 of file st24.cpp.

Referenced by st24_decode().

ST24_STX1

#define ST24_STX1   0x55

Definition at line 51 of file st24.cpp.

Referenced by st24_decode().

ST24_STX2

#define ST24_STX2   0x55

Definition at line 52 of file st24.cpp.

Referenced by st24_decode().

ST24_TARGET_MAX

#define ST24_TARGET_MAX   2000.0f

Definition at line 157 of file st24.cpp.

ST24_TARGET_MIN

#define ST24_TARGET_MIN   1000.0f

Definition at line 156 of file st24.cpp.

Enumeration Type Documentation

ST24_DECODE_STATE

enum ST24_DECODE_STATE

Enumerator
ST24_DECODE_STATE_UNSYNCED
ST24_DECODE_STATE_GOT_STX1
ST24_DECODE_STATE_GOT_STX2
ST24_DECODE_STATE_GOT_LEN
ST24_DECODE_STATE_GOT_TYPE
ST24_DECODE_STATE_GOT_DATA

Definition at line 143 of file st24.cpp.

ST24_PACKET_TYPE

enum ST24_PACKET_TYPE

Enumerator
ST24_PACKET_TYPE_CHANNELDATA12
ST24_PACKET_TYPE_CHANNELDATA24
ST24_PACKET_TYPE_TRANSMITTERGPSDATA

Definition at line 54 of file st24.cpp.

Function Documentation

st24_common_crc8()

static uint8_t st24_common_crc8 ( uint8_t *  ptr, uint8_t  len  )

static

Definition at line 168 of file st24.cpp.

Referenced by st24_decode().

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st24_decode()

int st24_decode	(	uint8_t	byte,
		uint8_t *	rssi,
		uint8_t *	rx_count,
		uint16_t *	channel_count,
		uint16_t *	channels,
		uint16_t	max_chan_count
	)

Decoder for ST24 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

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 195 of file st24.cpp.

Referenced by Linux::RCInput::add_st24_input().

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Variable Documentation

_decode_state

enum ST24_DECODE_STATE _decode_state = ST24_DECODE_STATE_UNSYNCED

static

Definition at line 163 of file st24.cpp.

Referenced by st24_decode().

_rxlen

uint8_t _rxlen

static

Definition at line 164 of file st24.cpp.

Referenced by st24_decode().

_rxpacket

ReceiverFcPacket _rxpacket

static

Definition at line 166 of file st24.cpp.