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finish LF ASK Sequence Terminator detection

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This commit is contained in:
marshmellow42 2016-02-19 15:09:51 -05:00
parent e452cfb4be
commit b96bcc795b
1 changed files with 20 additions and 12 deletions
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32
common/lfdemod.c
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@ -1529,11 +1529,12 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
uint8_t fndClk[] = {8,16,32,40,50,64,128}; uint8_t fndClk[] = {8,16,32,40,50,64,128};
int clk = 0; int clk = 0;
int tol = 0; int tol = 0;
int i, j, skip, start, end, low, high, minClk; int i, j, skip, start, end, low, high, minClk, waveStart;
bool complete = false; bool complete = false;
int tmpbuff[bufsize / 64]; int tmpbuff[bufsize / 64];
int waveLen[bufsize / 64];
size_t testsize = (bufsize < 512) ? bufsize : 512; size_t testsize = (bufsize < 512) ? bufsize : 512;
//int phaseoff = 0; int phaseoff = 0;
high = low = 128; high = low = 128;
memset(tmpbuff, 0, sizeof(tmpbuff)); memset(tmpbuff, 0, sizeof(tmpbuff));
@ -1541,7 +1542,6 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting"); if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
return false; //just noise return false; //just noise
} }
i = 0; i = 0;
j = 0; j = 0;
minClk = 255; minClk = 255;
@ -1560,11 +1560,14 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
start= i; start= i;
while ((buffer[i] < high) && (i < bufsize)) while ((buffer[i] < high) && (i < bufsize))
++i; ++i;
//first high point for this wave
waveStart = i;
while ((buffer[i] > low) && (i < bufsize)) while ((buffer[i] > low) && (i < bufsize))
++i; ++i;
if (j >= (bufsize/64)) { if (j >= (bufsize/64)) {
break; break;
} }
waveLen[j] = i - waveStart; //first high to first low
tmpbuff[j++] = i - start; tmpbuff[j++] = i - start;
if (i-start < minClk && i < bufsize) { if (i-start < minClk && i < bufsize) {
minClk = i - start; minClk = i - start;
@ -1592,10 +1595,10 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
start = -1; start = -1;
for (i = 0; i < j - 4; ++i) { for (i = 0; i < j - 4; ++i) {
skip += tmpbuff[i]; skip += tmpbuff[i];
if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior
if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol) { //2 clocks if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol) { //1 1/2 to 2 clocks if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= (clk*3)/2+tol) { //1 to 1 1/2 clocks for end of ST + first bit if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
start = i + 3; start = i + 3;
break; break;
} }
@ -1608,7 +1611,11 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting"); if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
return false; return false;
} }
if (waveLen[i+2] > clk*1+tol)
phaseoff = 0;
else
phaseoff = clk/2;
// skip over the remainder of ST // skip over the remainder of ST
skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
@ -1617,9 +1624,9 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
for (i += 3; i < j - 4; ++i) { for (i += 3; i < j - 4; ++i) {
end += tmpbuff[i]; end += tmpbuff[i];
if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior
if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol) { //2 clocks if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol) { //1 1/2 to 2 clocks if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= (clk*3)/2+tol) { //1 to 1 1/2 clocks for end of ST + first bit if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
complete = true; complete = true;
break; break;
} }
@ -1627,12 +1634,13 @@ bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
} }
} }
} }
end -= phaseoff;
//didn't find second ST - ERROR //didn't find second ST - ERROR
if (!complete) { if (!complete) {
if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting"); if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
return false; return false;
} }
if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d", skip, end, end-skip, clk, (end-skip)/clk); if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff);
//now begin to trim out ST so we can use normal demod cmds //now begin to trim out ST so we can use normal demod cmds
start = skip; start = skip;
size_t datalen = end - start; size_t datalen = end - start;