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AP_HAL: Change to shared CRC16 method

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murata 2019-04-04 14:32:58 +09:00 committed by Andrew Tridgell
parent 987966a6d7
commit dc452d41d2
2 changed files with 8 additions and 43 deletions
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30
libraries/AP_HAL/utility/srxl.cpp
View File

@ -23,6 +23,7 @@
#include <stdio.h> #include <stdio.h>
#include <stdint.h> #include <stdint.h>
#include <string.h> #include <string.h>
#include <AP_Math/crc.h>
#include "srxl.h" #include "srxl.h"
@ -69,31 +70,6 @@ static uint16_t crc_receiver = 0U; /* CRC extracted from srxl d
static uint16_t max_channels; static uint16_t max_channels;
/**
* 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
*/
static uint16_t 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;
}
/** /**
* Get RC channel information as microsecond pulsewidth representation from srxl version 1 and 2 * Get RC channel information as microsecond pulsewidth representation from srxl version 1 and 2
* *
@ -297,7 +273,7 @@ int srxl_decode(uint64_t timestamp_us, uint8_t byte, uint8_t *num_values, uint16
switch (decode_state) { switch (decode_state) {
case STATE_NEW: /* buffer header byte and prepare for frame reception and decoding */ case STATE_NEW: /* buffer header byte and prepare for frame reception and decoding */
buffer[0U]=byte; buffer[0U]=byte;
crc_fmu = srxl_crc16(0U,byte); crc_fmu = crc_xmodem_update(0U,byte);
buflen = 1U; buflen = 1U;
decode_state_next = STATE_COLLECT; decode_state_next = STATE_COLLECT;
break; break;
@ -315,7 +291,7 @@ int srxl_decode(uint64_t timestamp_us, uint8_t byte, uint8_t *num_values, uint16
buflen++; buflen++;
/* CRC not over last 2 frame bytes as these bytes inhabitate the crc */ /* CRC not over last 2 frame bytes as these bytes inhabitate the crc */
if (buflen <= (frame_len_full-2)) { 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 ) { if( buflen == frame_len_full ) {
/* CRC check here */ /* CRC check here */

21
libraries/AP_HAL/utility/sumd.cpp
View File

@ -45,6 +45,7 @@
#include <stdio.h> #include <stdio.h>
#include <stdint.h> #include <stdint.h>
#include <AP_Math/crc.h>
#include "sumd.h" #include "sumd.h"
#define SUMD_MAX_CHANNELS 32 #define SUMD_MAX_CHANNELS 32
@ -116,18 +117,6 @@ static uint8_t _rxlen;
static ReceiverFcPacketHoTT _rxpacket; static ReceiverFcPacketHoTT _rxpacket;
static uint16_t 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;
}
static uint8_t sumd_crc8(uint8_t crc, uint8_t value) static uint8_t sumd_crc8(uint8_t crc, uint8_t value)
{ {
crc += value; crc += value;
@ -153,7 +142,7 @@ int sumd_decode(uint8_t byte, uint8_t *rssi, uint8_t *rx_count, uint16_t *channe
_crc16 = 0x0000; _crc16 = 0x0000;
_crc8 = 0x00; _crc8 = 0x00;
_crcOK = false; _crcOK = false;
_crc16 = sumd_crc16(_crc16, byte); _crc16 = crc_xmodem_update(_crc16, byte);
_crc8 = sumd_crc8(_crc8, byte); _crc8 = sumd_crc8(_crc8, byte);
_decode_state = SUMD_DECODE_STATE_GOT_HEADER; _decode_state = SUMD_DECODE_STATE_GOT_HEADER;
@ -176,7 +165,7 @@ int sumd_decode(uint8_t byte, uint8_t *rssi, uint8_t *rx_count, uint16_t *channe
} }
if (_sumd) { if (_sumd) {
_crc16 = sumd_crc16(_crc16, byte); _crc16 = crc_xmodem_update(_crc16, byte);
} else { } else {
_crc8 = sumd_crc8(_crc8, byte); _crc8 = sumd_crc8(_crc8, byte);
@ -199,7 +188,7 @@ int sumd_decode(uint8_t byte, uint8_t *rssi, uint8_t *rx_count, uint16_t *channe
_rxpacket.length = byte; _rxpacket.length = byte;
if (_sumd) { if (_sumd) {
_crc16 = sumd_crc16(_crc16, byte); _crc16 = crc_xmodem_update(_crc16, byte);
} else { } else {
_crc8 = sumd_crc8(_crc8, byte); _crc8 = sumd_crc8(_crc8, byte);
@ -222,7 +211,7 @@ int sumd_decode(uint8_t byte, uint8_t *rssi, uint8_t *rx_count, uint16_t *channe
_rxpacket.sumd_data[_rxlen] = byte; _rxpacket.sumd_data[_rxlen] = byte;
if (_sumd) { if (_sumd) {
_crc16 = sumd_crc16(_crc16, byte); _crc16 = crc_xmodem_update(_crc16, byte);
} else { } else {
_crc8 = sumd_crc8(_crc8, byte); _crc8 = sumd_crc8(_crc8, byte);