+void CmdIOdemodFSK(int findone, int *high, int *low, int ledcontrol)
+{
+ uint8_t *dest = (uint8_t *)BigBuf;
+ int m=0, n=0, i=0, idx=0, lastval=0;
+ int found=0;
+ uint32_t code=0, code2=0;
+ //uint32_t hi2=0, hi=0, lo=0;
+
+ FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
+ FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
+
+ // 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();
+
+ for(;;) {
+ WDT_HIT();
+ if (ledcontrol)
+ LED_A_ON();
+ if(BUTTON_PRESS()) {
+ DbpString("Stopped");
+ if (ledcontrol)
+ LED_A_OFF();
+ return;
+ }
+
+ i = 0;
+ m = sizeof(BigBuf);
+ memset(dest,128,m);
+ 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 >= m) {
+ break;
+ }
+ }
+ }
+
+ // FSK demodulator
+
+ // sync to first lo-hi transition
+ for( idx=1; idx<m; idx++) {
+ if (dest[idx-1]<dest[idx])
+ lastval=idx;
+ break;
+ }
+ WDT_HIT();
+
+ // 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( i=0; idx<m; idx++) {
+ if (dest[idx-1]<dest[idx]) {
+ dest[i]=idx-lastval;
+ if (dest[i] <= 8) {
+ dest[i]=1;
+ } else {
+ dest[i]=0;
+ }
+
+ lastval=idx;
+ i++;
+ }
+ }
+ m=i;
+ WDT_HIT();
+
+ // we now have a set of cycle counts, loop over previous results and aggregate data into bit patterns
+ lastval=dest[0];
+ idx=0;
+ i=0;
+ n=0;
+ for( idx=0; idx<m; idx++) {
+ if (dest[idx]==lastval) {
+ n++;
+ } else {
+ // a bit time is five fc/10 or six fc/8 cycles so figure out how many bits a pattern width represents,
+ // an extra fc/8 pattern preceeds every 4 bits (about 200 cycles) just to complicate things but it gets
+ // swallowed up by rounding
+ // expected results are 1 or 2 bits, any more and it's an invalid manchester encoding
+ // special start of frame markers use invalid manchester states (no transitions) by using sequences
+ // like 111000
+ if (dest[idx-1]) {
+ n=(n+1)/7; // fc/8 in sets of 7
+ } else {
+ n=(n+1)/6; // fc/10 in sets of 6
+ }
+ switch (n) { // stuff appropriate bits in buffer
+ case 0:
+ case 1: // one bit
+ dest[i++]=dest[idx-1]^1;
+ //Dbprintf("%d",dest[idx-1]);
+ break;
+ case 2: // two bits
+ dest[i++]=dest[idx-1]^1;
+ dest[i++]=dest[idx-1]^1;
+ //Dbprintf("%d",dest[idx-1]);
+ //Dbprintf("%d",dest[idx-1]);
+ break;
+ case 3: // 3 bit start of frame markers
+ for(int j=0; j<3; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ case 4:
+ for(int j=0; j<4; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ case 5:
+ for(int j=0; j<5; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ case 6:
+ for(int j=0; j<6; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ case 7:
+ for(int j=0; j<7; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ case 8:
+ for(int j=0; j<8; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ case 9:
+ for(int j=0; j<9; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ case 10:
+ for(int j=0; j<10; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ case 11:
+ for(int j=0; j<11; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ case 12:
+ for(int j=0; j<12; j++){
+ dest[i++]=dest[idx-1]^1;
+ // Dbprintf("%d",dest[idx-1]);
+ }
+ break;
+ default: // this shouldn't happen, don't stuff any bits
+ //Dbprintf("%d",dest[idx-1]);
+ break;
+ }
+ n=0;
+ lastval=dest[idx];
+ }
+ }//end for
+ /*for(int j=0; j<64;j+=8){
+ Dbprintf("%d%d%d%d%d%d%d%d",dest[j],dest[j+1],dest[j+2],dest[j+3],dest[j+4],dest[j+5],dest[j+6],dest[j+7]);
+ }
+ Dbprintf("\n");*/
+ m=i;
+ WDT_HIT();
+
+ for( idx=0; idx<m-9; idx++) {
+ if ( !(dest[idx]) && !(dest[idx+1]) && !(dest[idx+2]) && !(dest[idx+3]) && !(dest[idx+4]) && !(dest[idx+5]) && !(dest[idx+6]) && !(dest[idx+7]) && !(dest[idx+8])&& (dest[idx+9])){
+ found=1;
+ //idx+=9;
+ if (found) {
+ Dbprintf("%d%d%d%d%d%d%d%d",dest[idx], dest[idx+1], dest[idx+2],dest[idx+3],dest[idx+4],dest[idx+5],dest[idx+6],dest[idx+7]);
+ Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+8], dest[idx+9], dest[idx+10],dest[idx+11],dest[idx+12],dest[idx+13],dest[idx+14],dest[idx+15]);
+ Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+16],dest[idx+17],dest[idx+18],dest[idx+19],dest[idx+20],dest[idx+21],dest[idx+22],dest[idx+23]);
+ Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+24],dest[idx+25],dest[idx+26],dest[idx+27],dest[idx+28],dest[idx+29],dest[idx+30],dest[idx+31]);
+ Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+32],dest[idx+33],dest[idx+34],dest[idx+35],dest[idx+36],dest[idx+37],dest[idx+38],dest[idx+39]);
+ Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+40],dest[idx+41],dest[idx+42],dest[idx+43],dest[idx+44],dest[idx+45],dest[idx+46],dest[idx+47]);
+ Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+48],dest[idx+49],dest[idx+50],dest[idx+51],dest[idx+52],dest[idx+53],dest[idx+54],dest[idx+55]);
+ Dbprintf("%d%d%d%d%d%d%d%d",dest[idx+56],dest[idx+57],dest[idx+58],dest[idx+59],dest[idx+60],dest[idx+61],dest[idx+62],dest[idx+63]);
+
+ short version='\x00';
+ char unknown='\x00';
+ uint16_t number=0;
+ for(int j=14;j<18;j++){
+ //Dbprintf("%d",dest[idx+j]);
+ version <<=1;
+ if (dest[idx+j]) version |= 1;
+ }
+ for(int j=19;j<27;j++){
+ //Dbprintf("%d",dest[idx+j]);
+ unknown <<=1;
+ if (dest[idx+j]) unknown |= 1;
+ }
+ for(int j=36;j<45;j++){
+ //Dbprintf("%d",dest[idx+j]);
+ number <<=1;
+ if (dest[idx+j]) number |= 1;
+ }
+ for(int j=46;j<53;j++){
+ //Dbprintf("%d",dest[idx+j]);
+ number <<=1;
+ if (dest[idx+j]) number |= 1;
+ }
+ for(int j=0; j<32; j++){
+ code <<=1;
+ if(dest[idx+j]) code |= 1;
+ }
+ for(int j=32; j<64; j++){
+ code2 <<=1;
+ if(dest[idx+j]) code2 |= 1;
+ }
+
+ Dbprintf("XSF(%02d)%02x:%d (%08x%08x)",version,unknown,number,code,code2);
+ if (ledcontrol)
+ LED_D_OFF();
+ }
+ // if we're only looking for one tag
+ if (findone){
+ //*high = hi;
+ //*low = lo;
+ LED_A_OFF();
+ return;
+ }
+
+ //hi=0;
+ //lo=0;
+ found=0;
+ }
+
+ }
+ }
+ WDT_HIT();
+}
projects / proxmark3-svn / blobdiff