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ISO15693 device side improvements (#652)
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* ISO15693 device side improvements
* increase accuracy by doubling the sample frequency (hi_read_rx_xcorr.v)
* adjust armsrc/iso15693.c and client/cmdhf15.c accordingly
* use more accurate approximation for sqrt(ci^2 + cq^2)
* improve EOF detection (was often mistaken for Logic0, resulting in "error, uneven octet! (extra bits!)")
* hi_read_r_xcorr.v: avoid overflows during accumulation and truncation
* explicitely cast unsigned ADC samples to signed
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@pwpiwi
pwpiwi committed Aug 15, 2018
1 parent c80eb8b commit 315e18e
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Showing 4 changed files with 175 additions and 131 deletions.
126 changes: 62 additions & 64 deletions armsrc/iso15693.c
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Expand Up @@ -81,7 +81,10 @@
#define AddCrc(data,datalen) Iso15693AddCrc(data,datalen)
#define sprintUID(target,uid) Iso15693sprintUID(target,uid)

int DEBUG=0;
// approximate amplitude=sqrt(ci^2+cq^2)
#define AMPLITUDE(ci, cq) (MAX(ABS(ci), ABS(cq)) + (MIN(ABS(ci), ABS(cq))>>1))

static int DEBUG = 0;


// ---------------------------
Expand Down Expand Up @@ -303,13 +306,9 @@ static int GetIso15693AnswerFromTag(uint8_t *receivedResponse, int maxLen, int *

// NOW READ RESPONSE
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR);
//spindelay(60); // greg - experiment to get rid of some of the 0 byte/failed reads
c = 0;
getNext = false;
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = 0x43;
}
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
int8_t b;
b = (int8_t)AT91C_BASE_SSC->SSC_RHR;
Expand All @@ -319,11 +318,11 @@ static int GetIso15693AnswerFromTag(uint8_t *receivedResponse, int maxLen, int *
// every other is Q. We just want power, so abs(I) + abs(Q) is
// close to what we want.
if(getNext) {
uint8_t r = ABS(b) + ABS(prev);
uint8_t r = AMPLITUDE(b, prev);

dest[c++] = (uint8_t)r;
dest[c++] = r;

if(c >= 2000) {
if(c >= 4000) {
break;
}
} else {
Expand All @@ -341,12 +340,10 @@ static int GetIso15693AnswerFromTag(uint8_t *receivedResponse, int maxLen, int *
int i, j;
int max = 0, maxPos=0;

int skip = 4;

// if(GraphTraceLen < 1000) return; // THIS CHECKS FOR A BUFFER TO SMALL
int skip = 2;

// First, correlate for SOF
for(i = 0; i < 100; i++) {
for(i = 0; i < 200; i++) { // usually, SOF is found around i = 60
int corr = 0;
for(j = 0; j < arraylen(FrameSOF); j += skip) {
corr += FrameSOF[j]*dest[i+(j/skip)];
Expand All @@ -356,7 +353,7 @@ static int GetIso15693AnswerFromTag(uint8_t *receivedResponse, int maxLen, int *
maxPos = i;
}
}
// Dbprintf("SOF at %d, correlation %d", maxPos,max/(arraylen(FrameSOF)/skip));
if (DEBUG) Dbprintf("SOF at %d, correlation %d", maxPos, max/(arraylen(FrameSOF)/skip));

int k = 0; // this will be our return value

Expand All @@ -370,22 +367,30 @@ static int GetIso15693AnswerFromTag(uint8_t *receivedResponse, int maxLen, int *
memset(outBuf, 0, sizeof(outBuf));
uint8_t mask = 0x01;
for(;;) {
int corr0 = 0, corr1 = 0, corrEOF = 0;
int corr0 = 0, corr00 = 0, corr01 = 0, corr1 = 0, corrEOF = 0;
for(j = 0; j < arraylen(Logic0); j += skip) {
corr0 += Logic0[j]*dest[i+(j/skip)];
}
corr01 = corr00 = corr0;
for(j = 0; j < arraylen(Logic0); j += skip) {
corr00 += Logic0[j]*dest[i+arraylen(Logic0)/skip+(j/skip)];
corr01 += Logic1[j]*dest[i+arraylen(Logic0)/skip+(j/skip)];
}
for(j = 0; j < arraylen(Logic1); j += skip) {
corr1 += Logic1[j]*dest[i+(j/skip)];
}
for(j = 0; j < arraylen(FrameEOF); j += skip) {
corrEOF += FrameEOF[j]*dest[i+(j/skip)];
}
// Even things out by the length of the target waveform.
corr00 *= 2;
corr01 *= 2;
corr0 *= 4;
corr1 *= 4;

if(corrEOF > corr1 && corrEOF > corr0) {
// Dbprintf("EOF at %d", i);
if(corrEOF > corr1 && corrEOF > corr00 && corrEOF > corr01) {
if (DEBUG) Dbprintf("EOF at %d, correlation %d (corr01: %d, corr00: %d, corr1: %d, corr0: %d)",
i, corrEOF, corr01, corr00, corr1, corr0);
break;
} else if(corr1 > corr0) {
i += arraylen(Logic1)/skip;
Expand All @@ -398,7 +403,7 @@ static int GetIso15693AnswerFromTag(uint8_t *receivedResponse, int maxLen, int *
k++;
mask = 0x01;
}
if((i+(int)arraylen(FrameEOF)) >= 2000) {
if((i+(int)arraylen(FrameEOF)/skip) >= 4000) {
DbpString("ran off end!");
break;
}
Expand Down Expand Up @@ -446,9 +451,6 @@ static int GetIso15693AnswerFromSniff(uint8_t *receivedResponse, int maxLen, int
c = 0;
getNext = false;
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = 0x43;
}
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
int8_t b = (int8_t)AT91C_BASE_SSC->SSC_RHR;

Expand All @@ -457,11 +459,11 @@ static int GetIso15693AnswerFromSniff(uint8_t *receivedResponse, int maxLen, int
// every other is Q. We just want power, so abs(I) + abs(Q) is
// close to what we want.
if(getNext) {
uint8_t r = ABS(b) + ABS(prev);
uint8_t r = AMPLITUDE(b, prev);

dest[c++] = (uint8_t)r;
dest[c++] = r;

if(c >= 20000) {
if(c >= BIGBUF_SIZE) {
break;
}
} else {
Expand All @@ -479,12 +481,10 @@ static int GetIso15693AnswerFromSniff(uint8_t *receivedResponse, int maxLen, int
int i, j;
int max = 0, maxPos=0;

int skip = 4;

// if(GraphTraceLen < 1000) return; // THIS CHECKS FOR A BUFFER TO SMALL
int skip = 2;

// First, correlate for SOF
for(i = 0; i < 19000; i++) {
for(i = 0; i < 38000; i++) {
int corr = 0;
for(j = 0; j < arraylen(FrameSOF); j += skip) {
corr += FrameSOF[j]*dest[i+(j/skip)];
Expand All @@ -494,7 +494,7 @@ static int GetIso15693AnswerFromSniff(uint8_t *receivedResponse, int maxLen, int
maxPos = i;
}
}
// DbpString("SOF at %d, correlation %d", maxPos,max/(arraylen(FrameSOF)/skip));
if (DEBUG) Dbprintf("SOF at %d, correlation %d", maxPos,max/(arraylen(FrameSOF)/skip));

int k = 0; // this will be our return value

Expand All @@ -508,22 +508,30 @@ static int GetIso15693AnswerFromSniff(uint8_t *receivedResponse, int maxLen, int
memset(outBuf, 0, sizeof(outBuf));
uint8_t mask = 0x01;
for(;;) {
int corr0 = 0, corr1 = 0, corrEOF = 0;
int corr0 = 0, corr00 = 0, corr01 = 0, corr1 = 0, corrEOF = 0;
for(j = 0; j < arraylen(Logic0); j += skip) {
corr0 += Logic0[j]*dest[i+(j/skip)];
}
corr01 = corr00 = corr0;
for(j = 0; j < arraylen(Logic0); j += skip) {
corr00 += Logic0[j]*dest[i+arraylen(Logic0)/skip+(j/skip)];
corr01 += Logic1[j]*dest[i+arraylen(Logic0)/skip+(j/skip)];
}
for(j = 0; j < arraylen(Logic1); j += skip) {
corr1 += Logic1[j]*dest[i+(j/skip)];
}
for(j = 0; j < arraylen(FrameEOF); j += skip) {
corrEOF += FrameEOF[j]*dest[i+(j/skip)];
}
// Even things out by the length of the target waveform.
corr00 *= 2;
corr01 *= 2;
corr0 *= 4;
corr1 *= 4;

if(corrEOF > corr1 && corrEOF > corr0) {
// DbpString("EOF at %d", i);
if(corrEOF > corr1 && corrEOF > corr00 && corrEOF > corr01) {
if (DEBUG) Dbprintf("EOF at %d, correlation %d (corr01: %d, corr00: %d, corr1: %d, corr0: %d)",
i, corrEOF, corr01, corr00, corr1, corr0);
break;
} else if(corr1 > corr0) {
i += arraylen(Logic1)/skip;
Expand All @@ -536,7 +544,7 @@ static int GetIso15693AnswerFromSniff(uint8_t *receivedResponse, int maxLen, int
k++;
mask = 0x01;
}
if((i+(int)arraylen(FrameEOF)) >= 2000) {
if((i+(int)arraylen(FrameEOF)/skip) >= BIGBUF_SIZE) {
DbpString("ran off end!");
break;
}
Expand Down Expand Up @@ -602,10 +610,6 @@ void AcquireRawAdcSamplesIso15693(void)
break;
}
}
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR;
(void)r;
}
WDT_HIT();
}

Expand All @@ -614,9 +618,6 @@ void AcquireRawAdcSamplesIso15693(void)
c = 0;
getNext = false;
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = 0x43;
}
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
int8_t b;
b = (int8_t)AT91C_BASE_SSC->SSC_RHR;
Expand All @@ -626,11 +627,11 @@ void AcquireRawAdcSamplesIso15693(void)
// every other is Q. We just want power, so abs(I) + abs(Q) is
// close to what we want.
if(getNext) {
uint8_t r = ABS(b) + ABS(prev);
uint8_t r = AMPLITUDE(b, prev);

dest[c++] = (uint8_t)r;
dest[c++] = r;

if(c >= 2000) {
if(c >= 4000) {
break;
}
} else {
Expand Down Expand Up @@ -668,9 +669,6 @@ void RecordRawAdcSamplesIso15693(void)
c = 0;
getNext = false;
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = 0x43;
}
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
int8_t b;
b = (int8_t)AT91C_BASE_SSC->SSC_RHR;
Expand All @@ -680,11 +678,11 @@ void RecordRawAdcSamplesIso15693(void)
// every other is Q. We just want power, so abs(I) + abs(Q) is
// close to what we want.
if(getNext) {
uint8_t r = ABS(b) + ABS(prev);
uint8_t r = AMPLITUDE(b, prev);

dest[c++] = (uint8_t)r;
dest[c++] = r;

if(c >= 7000) {
if(c >= 14000) {
break;
}
} else {
Expand Down Expand Up @@ -836,7 +834,7 @@ int SendDataTag(uint8_t *send, int sendlen, int init, int speed, uint8_t **recv)
if (init) Iso15693InitReader();

int answerLen=0;
uint8_t *answer = BigBuf_get_addr() + 3660;
uint8_t *answer = BigBuf_get_addr() + 4000;
if (recv != NULL) memset(answer, 0, 100);

if (!speed) {
Expand Down Expand Up @@ -957,7 +955,7 @@ void ReaderIso15693(uint32_t parameter)

int answerLen1 = 0;
int answerLen2 = 0;
int answerLen3 = 0;
// int answerLen3 = 0;
int i = 0;
int samples = 0;
int tsamples = 0;
Expand All @@ -967,11 +965,11 @@ void ReaderIso15693(uint32_t parameter)

FpgaDownloadAndGo(FPGA_BITSTREAM_HF);

uint8_t *answer1 = BigBuf_get_addr() + 3660;
uint8_t *answer2 = BigBuf_get_addr() + 3760;
uint8_t *answer3 = BigBuf_get_addr() + 3860;
uint8_t *answer1 = BigBuf_get_addr() + 4000;
uint8_t *answer2 = BigBuf_get_addr() + 4100;
// uint8_t *answer3 = BigBuf_get_addr() + 4200;
// Blank arrays
memset(answer1, 0x00, 300);
memset(answer1, 0x00, 200);

SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
// Setup SSC
Expand Down Expand Up @@ -1025,21 +1023,21 @@ void ReaderIso15693(uint32_t parameter)
TagUID[3],TagUID[2],TagUID[1],TagUID[0]);


Dbprintf("%d octets read from SELECT request:", answerLen2);
DbdecodeIso15693Answer(answerLen2,answer2);
Dbhexdump(answerLen2,answer2,true);
// Dbprintf("%d octets read from SELECT request:", answerLen2);
// DbdecodeIso15693Answer(answerLen2,answer2);
// Dbhexdump(answerLen2,answer2,true);

Dbprintf("%d octets read from XXX request:", answerLen3);
DbdecodeIso15693Answer(answerLen3,answer3);
Dbhexdump(answerLen3,answer3,true);
// Dbprintf("%d octets read from XXX request:", answerLen3);
// DbdecodeIso15693Answer(answerLen3,answer3);
// Dbhexdump(answerLen3,answer3,true);

// read all pages
if (answerLen1>=12 && DEBUG) {
i=0;
while (i<32) { // sanity check, assume max 32 pages
BuildReadBlockRequest(TagUID,i);
TransmitTo15693Tag(ToSend,ToSendMax,&tsamples, &wait);
answerLen2 = GetIso15693AnswerFromTag(answer2, 100, &samples, &elapsed);
TransmitTo15693Tag(ToSend,ToSendMax,&tsamples, &wait);
answerLen2 = GetIso15693AnswerFromTag(answer2, 100, &samples, &elapsed);
if (answerLen2>0) {
Dbprintf("READ SINGLE BLOCK %d returned %d octets:",i,answerLen2);
DbdecodeIso15693Answer(answerLen2,answer2);
Expand Down Expand Up @@ -1073,7 +1071,7 @@ void SimTagIso15693(uint32_t parameter, uint8_t *uid)

FpgaDownloadAndGo(FPGA_BITSTREAM_HF);

uint8_t *buf = BigBuf_get_addr() + 3660;
uint8_t *buf = BigBuf_get_addr() + 4000;
memset(buf, 0x00, 100);

SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
Expand Down Expand Up @@ -1177,7 +1175,7 @@ void DirectTag15693Command(uint32_t datalen,uint32_t speed, uint32_t recv, uint8

if (recv) {
LED_B_ON();
cmd_send(CMD_ACK,recvlen>48?48:recvlen,0,0,recvbuf,48);
cmd_send(CMD_ACK,recvlen>48?48:recvlen,0,0,recvbuf,48);
LED_B_OFF();

if (DEBUG) {
Expand Down

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