#include "crc16.h"
#include "string.h"
-// split into two routines so we can avoid timing issues after sending commands //
-void DoAcquisition125k_internal(bool silent)
+
+/**
+* Does the sample acquisition. If threshold is specified, the actual sampling
+* is not commenced until the threshold has been reached.
+* @param trigger_threshold - the threshold
+* @param silent - is true, now outputs are made. If false, dbprints the status
+*/
+void DoAcquisition125k_internal(int trigger_threshold,bool silent)
{
uint8_t *dest = (uint8_t *)BigBuf;
int n = sizeof(BigBuf);
}
if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY) {
dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
- i++;
LED_D_OFF();
- if (i >= n) break;
+ if (trigger_threshold != -1 && dest[i] < trigger_threshold)
+ continue;
+ else
+ trigger_threshold = -1;
+ if (++i >= n) break;
}
}
- if( ! silent)
+ if(!silent)
{
Dbprintf("buffer samples: %02x %02x %02x %02x %02x %02x %02x %02x ...",
dest[0], dest[1], dest[2], dest[3], dest[4], dest[5], dest[6], dest[7]);
+
}
}
-
-void DoAcquisition125k(void)
+/**
+* Perform sample aquisition.
+*/
+void DoAcquisition125k(int trigger_threshold)
{
- DoAcquisition125k_internal(false);
+ DoAcquisition125k_internal(trigger_threshold, false);
}
-void SetupToAcquireRawAdcSamples(int divisor)
+/**
+* Setup the FPGA to listen for samples. This method downloads the FPGA bitstream
+* if not already loaded, sets divisor and starts up the antenna.
+* @param divisor : 1, 88> 255 or negative ==> 134.8 KHz
+* 0 or 95 ==> 125 KHz
+*
+**/
+void LFSetupFPGAForADC(int divisor, bool lf_field)
{
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
if ( (divisor == 1) || (divisor < 0) || (divisor > 255) )
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
else if (divisor == 0)
else
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor);
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | (lf_field ? FPGA_LF_ADC_READER_FIELD : 0));
// Connect the A/D to the peak-detected low-frequency path.
SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
-
// Give it a bit of time for the resonant antenna to settle.
SpinDelay(50);
-
// Now set up the SSC to get the ADC samples that are now streaming at us.
FpgaSetupSsc();
}
-
+/**
+* Initializes the FPGA, and acquires the samples.
+**/
void AcquireRawAdcSamples125k(int divisor)
{
- SetupToAcquireRawAdcSamples(divisor);
+ LFSetupFPGAForADC(divisor, true);
// Now call the acquisition routine
- DoAcquisition125k_internal(false);
+ DoAcquisition125k_internal(-1,false);
+}
+/**
+* Initializes the FPGA for snoop-mode, and acquires the samples.
+**/
+
+void SnoopLFRawAdcSamples(int divisor, int trigger_threshold)
+{
+ LFSetupFPGAForADC(divisor, false);
+ DoAcquisition125k(trigger_threshold);
}
void ModThenAcquireRawAdcSamples125k(int delay_off, int period_0, int period_1, uint8_t *command)
{
- int at134khz;
/* Make sure the tag is reset */
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
SpinDelay(2500);
+
+ int divisor_used = 95; // 125 KHz
// see if 'h' was specified
- if (command[strlen((char *) command) - 1] == 'h')
- at134khz = TRUE;
- else
- at134khz = FALSE;
- if (at134khz)
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
- else
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+ if (command[strlen((char *) command) - 1] == 'h')
+ divisor_used = 88; // 134.8 KHz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
// Give it a bit of time for the resonant antenna to settle.
SpinDelay(50);
+
// And a little more time for the tag to fully power up
SpinDelay(2000);
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LED_D_OFF();
SpinDelayUs(delay_off);
- if (at134khz)
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
- else
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used);
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
LED_D_ON();
if(*(command++) == '0')
SpinDelayUs(period_0);
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LED_D_OFF();
SpinDelayUs(delay_off);
- if (at134khz)
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
- else
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, divisor_used);
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
// now do the read
- DoAcquisition125k();
+ DoAcquisition125k(-1);
}
/* blank r/w tag data stream
uint32_t threshold = (sampleslo - sampleshi + 1)>>1;
// TI tags charge at 134.2Khz
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 88); //134.8Khz
// Place FPGA in passthrough mode, in this mode the CROSS_LO line
// if not provided a valid crc will be computed from the data and written.
void WriteTItag(uint32_t idhi, uint32_t idlo, uint16_t crc)
{
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
if(crc == 0) {
crc = update_crc16(crc, (idlo)&0xff);
crc = update_crc16(crc, (idlo>>8)&0xff);
int i;
uint8_t *tab = (uint8_t *)BigBuf;
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_EDGE_DETECT);
AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT | GPIO_SSC_CLK;
if (ledcontrol)
LED_A_OFF();
}
-void setup_for_125khz()
-{
- FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
-
- // Connect the A/D to the peak-detected low-frequency path.
- SetAdcMuxFor(GPIO_MUXSEL_LOPKD);
-
- // Give it a bit of time for the resonant antenna to settle.
- SpinDelay(50);
-
- // Now set up the SSC to get the ADC samples that are now streaming at us.
- FpgaSetupSsc();
-
-}
-void get_samples(int ledcontrol, uint8_t* dest, int size)
-{
- int i = 0;
-
- memset(dest,128,size);
- for(;;) {
- if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
- AT91C_BASE_SSC->SSC_THR = 0x43;
- if (ledcontrol) LED_D_ON();
- }
- if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
- dest[i] = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
- // we don't care about actual value, only if it's more or less than a
- // threshold essentially we capture zero crossings for later analysis
- if(dest[i] < 127) dest[i] = 0; else dest[i] = 1;
- i++;
- if (ledcontrol) LED_D_OFF();
- if(i >= size) {
- break;
- }
- }
- }
-}
-uint8_t fsk_demod(uint8_t * dest, int size)
+size_t fsk_demod(uint8_t * dest, size_t size)
{
- uint8_t last_transition = 0;
- uint8_t idx = 1;
+ uint32_t last_transition = 0;
+ uint32_t idx = 1;
// we don't care about actual value, only if it's more or less than a
// threshold essentially we capture zero crossings for later analysis
uint8_t threshold_value = 127;
- WDT_HIT();
-
// sync to first lo-hi transition, and threshold
//Need to threshold first sample
if(dest[0] < threshold_value) dest[0] = 0;
else dest[0] = 1;
- uint8_t numBits = 0;
+ size_t numBits = 0;
// count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
// or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
// between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
for(idx = 1; idx < size; idx++) {
-
// threshold current value
if (dest[idx] < threshold_value) dest[idx] = 0;
else dest[idx] = 1;
return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
}
-uint8_t aggregate_bits(uint8_t *dest,uint8_t size, uint8_t h2l_crossing_value,uint8_t l2h_crossing_value, uint8_t maxConsequtiveBits )
+
+size_t aggregate_bits(uint8_t *dest,size_t size, uint8_t h2l_crossing_value,uint8_t l2h_crossing_value, uint8_t maxConsequtiveBits )
{
uint8_t lastval=dest[0];
- uint8_t idx=0;
- uint8_t numBits=0;
- uint8_t n=1, i=0;
+ uint32_t idx=0;
+ size_t numBits=0;
+ uint32_t n=1;
for( idx=1; idx < size; idx++) {
continue;
}
//if lastval was 1, we have a 1->0 crossing
- if ( lastval ) {
- n=(n+1)/7;
+ if ( dest[idx-1] ) {
+ n=(n+1) / h2l_crossing_value;
} else {// 0->1 crossing
- n=(n+1)/6;
+ n=(n+1) / l2h_crossing_value;
}
- if(n < 13)
+ if (n == 0) n = 1;
+
+ if(n < maxConsequtiveBits)
{
- memset(dest+i, lastval ^ 1, n);
+ memset(dest+numBits, dest[idx-1] , n);
numBits += n;
}
n=0;
{
uint8_t *dest = (uint8_t *)BigBuf;
- int size=0, idx=0, found=0;
+ size_t size=0,idx=0; //, found=0;
uint32_t hi2=0, hi=0, lo=0;
// Configure to go in 125Khz listen mode
- SetupToAcquireRawAdcSamples(0);
+ LFSetupFPGAForADC(95, true);
- for(;;) {
- WDT_HIT();
- if (ledcontrol)
- LED_A_ON();
- if(BUTTON_PRESS()) {
- DbpString("Stopped");
- if (ledcontrol)
- LED_A_OFF();
- return;
- }
+ while(!BUTTON_PRESS()) {
+ WDT_HIT();
+ if (ledcontrol) LED_A_ON();
- DoAcquisition125k_internal(true);
+ DoAcquisition125k_internal(-1,true);
size = sizeof(BigBuf);
// FSK demodulator
size = fsk_demod(dest, size);
- WDT_HIT();
-
// we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
-
// 1->0 : fc/8 in sets of 6
// 0->1 : fc/10 in sets of 5
size = aggregate_bits(dest,size, 6,5,5);
// final loop, go over previously decoded manchester data and decode into usable tag ID
// 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
uint8_t frame_marker_mask[] = {1,1,1,0,0,0};
+ int numshifts = 0;
+ idx = 0;
+ while( idx + sizeof(frame_marker_mask) < size) {
+ // search for a start of frame marker
+ if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
+ { // frame marker found
+ idx+=sizeof(frame_marker_mask);
- for( idx=0; idx < size-sizeof(frame_marker_mask); idx++) {
-
- if (found) {
- if(dest[idx] == dest[idx+1])
- {// 1 1 or 00
- found=0;
- hi2=0;
- hi=0;
- lo=0;
- }else
- {
- //Shift in a bit. Start by shifting high registers
+ while(dest[idx] != dest[idx+1] && idx < size-2)
+ {
+ // Keep going until next frame marker (or error)
+ // Shift in a bit. Start by shifting high registers
hi2 = (hi2<<1)|(hi>>31);
hi = (hi<<1)|(lo>>31);
//Then, shift in a 0 or one into low
if (dest[idx] && !dest[idx+1]) // 1 0
lo=(lo<<1)|0;
else // 0 1
- lo=(lo<<1)|1;
+ lo=(lo<<1)|
+ 1;
+ numshifts ++;
+ idx += 2;
}
- idx++;
- }
-
- // search for a start of frame marker
- if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
- { // Found start of frame marker
- found=1;
- idx+=sizeof(frame_marker_mask);
- if (found && (hi2|hi|lo)) {
- if (hi2 != 0){
- Dbprintf("TAG ID: %x%08x%08x (%d)",
- (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
- }
- else {
- Dbprintf("TAG ID: %x%08x (%d)",
- (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
- }
- /* if we're only looking for one tag */
- if (findone)
+ //Dbprintf("Num shifts: %d ", numshifts);
+ // Hopefully, we read a tag and hit upon the next frame marker
+ if(idx + sizeof(frame_marker_mask) < size)
+ {
+ if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
{
- *high = hi;
- *low = lo;
- return;
+ if (hi2 != 0){
+ Dbprintf("TAG ID: %x%08x%08x (%d)",
+ (unsigned int) hi2, (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+ }
+ else {
+ Dbprintf("TAG ID: %x%08x (%d)",
+ (unsigned int) hi, (unsigned int) lo, (unsigned int) (lo>>1) & 0xFFFF);
+ }
}
- hi2=0;
- hi=0;
- lo=0;
- found=0;
+
}
+
+ // reset
+ hi2 = hi = lo = 0;
+ numshifts = 0;
+ }else
+ {
+ idx++;
}
}
WDT_HIT();
+
}
+ DbpString("Stopped");
+ if (ledcontrol) LED_A_OFF();
}
uint32_t bytebits_to_byte(uint8_t* src, int numbits)
void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
{
uint8_t *dest = (uint8_t *)BigBuf;
- int size=0, idx=0;
+
+ size_t size=0, idx=0;
uint32_t code=0, code2=0;
- //uint32_t hi2=0, hi=0, lo=0;
- setup_for_125khz();
+ // Configure to go in 125Khz listen mode
+ LFSetupFPGAForADC(95, true);
+
+ while(!BUTTON_PRESS()) {
+
- for(;;) {
WDT_HIT();
- if (ledcontrol)
- LED_A_ON();
- if(BUTTON_PRESS()) {
- DbpString("Stopped");
- if (ledcontrol)
- LED_A_OFF();
- return;
- }
+ if (ledcontrol) LED_A_ON();
- DoAcquisition125k_internal(true);
+ DoAcquisition125k_internal(-1,true);
size = sizeof(BigBuf);
// FSK demodulator
size = fsk_demod(dest, size);
- WDT_HIT();
+
// we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
// 1->0 : fc/8 in sets of 7
// 0->1 : fc/10 in sets of 6
WDT_HIT();
+ //Handle the data
uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1};
for( idx=0; idx < size - 64; idx++) {
return;
}
}
+ WDT_HIT();
}
- WDT_HIT();
+ DbpString("Stopped");
+ if (ledcontrol) LED_A_OFF();
}
/*------------------------------
// Write one bit to card
void T55xxWriteBit(int bit)
{
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
if (bit == 0)
SpinDelayUs(WRITE_0);
else
{
unsigned int i;
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
// Give it a bit of time for the resonant antenna to settle.
// And for the tag to fully power up
// Now perform write (nominal is 5.6 ms for T55x7 and 18ms for E5550,
// so wait a little more)
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
SpinDelay(20);
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
}
uint8_t *dest = (uint8_t *)BigBuf;
int m=0, i=0;
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
m = sizeof(BigBuf);
// Clear destination buffer before sending the command
memset(dest, 128, m);
LED_D_ON();
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
// Give it a bit of time for the resonant antenna to settle.
// And for the tag to fully power up
// Turn field on to read the response
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
// Now do the acquisition
i = 0;
uint8_t *dest = (uint8_t *)BigBuf;
int m=0, i=0;
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
m = sizeof(BigBuf);
// Clear destination buffer before sending the command
memset(dest, 128, m);
LED_D_ON();
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
// Give it a bit of time for the resonant antenna to settle.
// And for the tag to fully power up
// Turn field on to read the response
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
// Now do the acquisition
i = 0;
LED_D_ON();
//Field on
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
// Give it a bit of time for the resonant antenna to settle.
// And for the tag to fully power up
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
SpinDelayUs(55*8); //55 cycles off (8us each)for 4305
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);//field on
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
SpinDelayUs(16*8); //16 cycles on (8us each)
// now start writting
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); // field off
SpinDelayUs(23*8); //16-4 cycles off (8us each)
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
- FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_READER);//field on
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);//field on
SpinDelayUs(9*8); //16 cycles on (8us each)
}
}