Mirror
/
ardupilot
mirror of https://github.com/ArduPilot/ardupilot
5
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

AP_RCProtocol: Change to shared CRC16 method

This commit is contained in:
murata 2019-04-04 14:32:24 +09:00 committed by Andrew Tridgell
parent 428d4d4574
commit 987966a6d7
4 changed files with 8 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
libraries/AP_RCProtocol/AP_RCProtocol_SRXL.cpp
View File

@ -21,32 +21,11 @@
*/
#include "AP_RCProtocol_SRXL.h"
#include <AP_Math/crc.h>
// #define SUMD_DEBUG
extern const AP_HAL::HAL& hal;
/**
* This function calculates the 16bit crc as used throughout the srxl protocol variants
*
* This function is intended to be called whenever a new byte shall be added to the crc.
* Simply provide the old crc and the new data byte and the function return the new crc value.
*
* To start a new crc calculation for a new srxl frame, provide parameter crc=0 and the first byte of the frame.
*
* @param[in] crc - start value for crc
* @param[in] new_byte - byte that shall be included in crc calculation
* @return calculated crc
*/
uint16_t AP_RCProtocol_SRXL::srxl_crc16(uint16_t crc, uint8_t new_byte)
{
uint8_t loop;
crc = crc ^ (uint16_t)new_byte << 8;
for (loop = 0; loop < 8; loop++) {
crc = (crc & 0x8000) ? (crc << 1) ^ 0x1021 : (crc << 1);
}
return crc;
}
void AP_RCProtocol_SRXL::process_pulse(uint32_t width_s0, uint32_t width_s1)
{
uint8_t b;
@ -229,7 +208,7 @@ void AP_RCProtocol_SRXL::_process_byte(uint32_t timestamp_us, uint8_t byte)
switch (decode_state) {
case STATE_NEW: /* buffer header byte and prepare for frame reception and decoding */
buffer[0U]=byte;
crc_fmu = srxl_crc16(0U,byte);
crc_fmu = crc_xmodem_update(0U,byte);
buflen = 1U;
decode_state_next = STATE_COLLECT;
break;
@ -247,7 +226,7 @@ void AP_RCProtocol_SRXL::_process_byte(uint32_t timestamp_us, uint8_t byte)
buflen++;
/* CRC not over last 2 frame bytes as these bytes inhabitate the crc */
if (buflen <= (frame_len_full-2)) {
crc_fmu = srxl_crc16(crc_fmu,byte);
crc_fmu = crc_xmodem_update(crc_fmu,byte);
}
if (buflen == frame_len_full) {
/* CRC check here */

1
libraries/AP_RCProtocol/AP_RCProtocol_SRXL.h
View File

@ -43,7 +43,6 @@ public:
void process_byte(uint8_t byte, uint32_t baudrate) override;
private:
void _process_byte(uint32_t timestamp_us, uint8_t byte);
static uint16_t srxl_crc16(uint16_t crc, uint8_t new_byte);
int srxl_channels_get_v1v2(uint16_t max_values, uint8_t *num_values, uint16_t *values, bool *failsafe_state);
int srxl_channels_get_v5(uint16_t max_values, uint8_t *num_values, uint16_t *values, bool *failsafe_state);
uint8_t buffer[SRXL_FRAMELEN_MAX]; /* buffer for raw srxl frame data in correct order --> buffer[0]=byte0 buffer[1]=byte1 */

22
libraries/AP_RCProtocol/AP_RCProtocol_SUMD.cpp
View File

@ -43,6 +43,7 @@
* @author Marco Bauer <marco@wtns.de>
*/
#include "AP_RCProtocol_SUMD.h"
#include <AP_Math/crc.h>
#define SUMD_HEADER_LENGTH 3
#define SUMD_HEADER_ID 0xA8
@ -64,18 +65,6 @@
// #define SUMD_DEBUG
extern const AP_HAL::HAL& hal;
uint16_t AP_RCProtocol_SUMD::sumd_crc16(uint16_t crc, uint8_t value)
{
int i;
crc ^= (uint16_t)value << 8;
for (i = 0; i < 8; i++) {
crc = (crc & 0x8000) ? (crc << 1) ^ 0x1021 : (crc << 1);
}
return crc;
}
uint8_t AP_RCProtocol_SUMD::sumd_crc8(uint8_t crc, uint8_t value)
{
crc += value;
@ -107,7 +96,7 @@ void AP_RCProtocol_SUMD::_process_byte(uint32_t timestamp_us, uint8_t byte)
_crc16 = 0x0000;
_crc8 = 0x00;
_crcOK = false;
_crc16 = sumd_crc16(_crc16, byte);
_crc16 = crc_xmodem_update(_crc16, byte);
_crc8 = sumd_crc8(_crc8, byte);
_decode_state = SUMD_DECODE_STATE_GOT_HEADER;
@ -127,7 +116,7 @@ void AP_RCProtocol_SUMD::_process_byte(uint32_t timestamp_us, uint8_t byte)
}
if (_sumd) {
_crc16 = sumd_crc16(_crc16, byte);
_crc16 = crc_xmodem_update(_crc16, byte);
} else {
_crc8 = sumd_crc8(_crc8, byte);
@ -150,7 +139,7 @@ void AP_RCProtocol_SUMD::_process_byte(uint32_t timestamp_us, uint8_t byte)
_rxpacket.length = byte;
if (_sumd) {
_crc16 = sumd_crc16(_crc16, byte);
_crc16 = crc_xmodem_update(_crc16, byte);
} else {
_crc8 = sumd_crc8(_crc8, byte);
@ -173,7 +162,7 @@ void AP_RCProtocol_SUMD::_process_byte(uint32_t timestamp_us, uint8_t byte)
_rxpacket.sumd_data[_rxlen] = byte;
if (_sumd) {
_crc16 = sumd_crc16(_crc16, byte);
_crc16 = crc_xmodem_update(_crc16, byte);
} else {
_crc8 = sumd_crc8(_crc8, byte);
@ -341,4 +330,3 @@ void AP_RCProtocol_SUMD::process_byte(uint8_t byte, uint32_t baudrate)
}
_process_byte(AP_HAL::micros(), byte);
}

1
libraries/AP_RCProtocol/AP_RCProtocol_SUMD.h
View File

@ -30,7 +30,6 @@ public:
private:
void _process_byte(uint32_t timestamp_us, uint8_t byte);
static uint16_t sumd_crc16(uint16_t crc, uint8_t value);
static uint8_t sumd_crc8(uint8_t crc, uint8_t value);
#pragma pack(push, 1)