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Re #2999: More strict SBUS frame check (only allow 25 byte frames, ch… (#3501)

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* Re #2999: More strict SBUS frame check (only allow 25 byte frames, check end byte)

* SBUS fixes
This commit is contained in:
Damjan Adamic
2016-05-19 06:30:19 +02:00
committed by Bertrand Songis
parent 7eba760797
commit 29a139559d
2 changed files with 17 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files
radio/src/sbus.cpp
+16 -21
View File
@@ -24,40 +24,31 @@
#define SBUS_FRAME_GAP_DELAY 1000 // 500uS
#define SBUS_START_BYTE 0x0F
#define SBUS_END_BYTE 0x00
#define SBUS_FLAGS_IDX 23
#define SBUS_FRAMELOST_BIT 2
#define SBUS_FAILSAFE_BIT 3
#define SBUS_CH_BITS 11
#define SBUS_CH_MASK ((1<<SBUS_CH_BITS)-1)
#define SBUS_CH_BITS 11
#define SBUS_CH_MASK ((1<<SBUS_CH_BITS)-1)
#define SBUS_CH_CENTER 0x3E0
#define SBUS_CH_CENTER 0x3E0
uint8_t SbusFrame[SBUS_MAX_FRAME_SIZE];
uint16_t SbusTimer ;
uint8_t SbusIndex = 0 ;
// Range for pulses (ppm input) is [-512:+512]
void processSbusFrame(uint8_t * sbus, int16_t * pulses, uint32_t size)
{
uint32_t inputbitsavailable = 0;
uint32_t inputbits = 0;
if (sbus[0] != SBUS_START_BYTE) {
if (size != SBUS_FRAME_SIZE || sbus[0] != SBUS_START_BYTE || sbus[SBUS_FRAME_SIZE-1] != SBUS_END_BYTE) {
return; // not a valid SBUS frame
}
if (size < SBUS_MIN_FRAME_SIZE) {
return;
}
if (size > SBUS_FLAGS_IDX && ((sbus[SBUS_FLAGS_IDX] & (1<<SBUS_FAILSAFE_BIT)) || (sbus[SBUS_FLAGS_IDX] & (1<<SBUS_FRAMELOST_BIT)))) {
if ((sbus[SBUS_FLAGS_IDX] & (1<<SBUS_FAILSAFE_BIT)) || (sbus[SBUS_FLAGS_IDX] & (1<<SBUS_FRAMELOST_BIT))) {
return; // SBUS invalid frame or failsafe mode
}
// Skip start byte
sbus++;
sbus++; // skip start byte
uint32_t inputbitsavailable = 0;
uint32_t inputbits = 0;
for (uint32_t i=0; i<NUM_TRAINER; i++) {
while (inputbitsavailable < SBUS_CH_BITS) {
inputbits |= *sbus++ << inputbitsavailable;
@@ -76,12 +67,16 @@ void processSbusInput()
#if !defined(SIMU)
uint8_t rxchar;
uint32_t active = 0;
static uint8_t SbusIndex = 0;
static uint16_t SbusTimer;
static uint8_t SbusFrame[SBUS_FRAME_SIZE];
while (sbusGetByte(&rxchar)) {
active = 1;
SbusFrame[SbusIndex++] = rxchar;
if (SbusIndex > SBUS_MAX_FRAME_SIZE-1) {
SbusIndex = SBUS_MAX_FRAME_SIZE-1;
if (SbusIndex > SBUS_FRAME_SIZE-1) {
SbusIndex = SBUS_FRAME_SIZE-1;
}
SbusFrame[SbusIndex++] = rxchar;
}
if (active) {
SbusTimer = getTmr2MHz();
radio/src/sbus.h
+1 -2
View File
@@ -22,8 +22,7 @@
#define _SBUS_H_
#define SBUS_BAUDRATE 100000
#define SBUS_MIN_FRAME_SIZE 23
#define SBUS_MAX_FRAME_SIZE 28
#define SBUS_FRAME_SIZE 25
void processSbusInput();