CHG: this timing should be quite good. needs to be verified.

[proxmark3-svn] / client / ui.c

diff --git a/client/ui.c b/client/ui.c
index 48a55b1fdfea12e5d9d9c26cc737d9e50b3049cb..cfaec6a510dcfaadfe4edc725a41eeddf461097c 100644 (file)
--- a/client/ui.c
+++ b/client/ui.c
@@ -80,27 +80,31 @@ void SetLogFilename(char *fn) {
   logfilename = fn;
 }
  
-void iceFsk3(int * data, const size_t len){
+void iceIIR_Butterworth(int *data, const size_t len){
 
        int i,j;
        
        int * output =  (int* ) malloc(sizeof(int) * len);      
+       if ( !output ) return;
+       
+       // clear mem
        memset(output, 0x00, len);
-       float fc           = 0.1125f;          // center frequency
-       size_t adjustedLen = len;
        
+       size_t adjustedLen = len;
+       float fc = 0.1125f;          // center frequency
+               
     // create very simple low-pass filter to remove images (2nd-order Butterworth)
     float complex iir_buf[3] = {0,0,0};
     float b[3] = {0.003621681514929,  0.007243363029857, 0.003621681514929};
     float a[3] = {1.000000000000000, -1.822694925196308, 0.837181651256023};
     
-    float sample           = 0;      // input sample read from file
+    float sample           = 0;      // input sample read from array
     float complex x_prime  = 1.0f;   // save sample for estimating frequency
     float complex x;
                
-       for (i=0; i<adjustedLen; ++i) {
+       for (i = 0; i < adjustedLen; ++i) {
 
-               sample = data[i]+128;
+               sample = data[i];
                
         // remove DC offset and mix to complex baseband
         x = (sample - 127.5f) * cexpf( _Complex_I * 2 * M_PI * fc * i );
@@ -118,71 +122,36 @@ void iceFsk3(int * data, const size_t len){
         float freq = cargf(x*conjf(x_prime));
         x_prime = x;    // retain this sample for next iteration
 
-               output[i] =(freq > 0)? 10 : -10;
+               output[i] =(freq > 0) ? 127 : -127;
     } 
 
        // show data
+       //memcpy(data, output, adjustedLen);
        for (j=0; j<adjustedLen; ++j)
                data[j] = output[j];
-               
-       CmdLtrim("30");
-       adjustedLen -= 30;
-       
-       // zero crossings.
-       for (j=0; j<adjustedLen; ++j){
-               if ( data[j] == 10) break;
-       }
-       int startOne =j;
-       
-       for (;j<adjustedLen; ++j){
-               if ( data[j] == -10 ) break;
-       }
-       int stopOne = j-1;
-       
-       int fieldlen = stopOne-startOne;
-       
-       fieldlen = (fieldlen == 39 || fieldlen == 41)? 40 : fieldlen;
-       fieldlen = (fieldlen == 59 || fieldlen == 51)? 50 : fieldlen;
-       if ( fieldlen != 40 && fieldlen != 50){
-               printf("Detected field Length: %d \n", fieldlen);
-               printf("Can only handle 40 or 50.  Aborting...\n");
-               free(output);
-               return;
-       }
-       
-       // FSK sequence start == 000111
-       int startPos = 0;
-       for (i =0; i<adjustedLen; ++i){
-               int dec = 0;
-               for ( j = 0; j < 6*fieldlen; ++j){
-                       dec += data[i + j];
-               }
-               if (dec == 0) {
-                       startPos = i;
-                       break;
-               }
-       }
        
-       printf("000111 position: %d \n", startPos);
+       free(output);
+}
 
-       startPos += 6*fieldlen+5;
-       
-       int bit =0;
-       printf("BINARY\n");
-       printf("R/40 :  ");
-       for (i =startPos ; i < adjustedLen; i += 40){
-               bit = data[i]>0 ? 1:0;
-               printf("%d", bit );
+void iceSimple_Filter(int *data, const size_t len, uint8_t k){
+// ref: http://www.edn.com/design/systems-design/4320010/A-simple-software-lowpass-filter-suits-embedded-system-applications
+// parameter K
+#define FILTER_SHIFT 4 
+
+       int32_t filter_reg = 0;
+       int16_t input, output;
+       int8_t shift = (k <=8 ) ? k : FILTER_SHIFT;
+
+       for (int i = 0; i < len; ++i){
+
+               input = data[i];
+               // Update filter with current sample
+               filter_reg = filter_reg - (filter_reg >> shift) + input;
+
+               // Scale output for unity gain
+               output = filter_reg >> shift;
+               data[i] = output;
        }
-       printf("\n");   
-       
-       printf("R/50 :  ");
-       for (i =startPos ; i < adjustedLen; i += 50){
-               bit = data[i]>0 ? 1:0;
-               printf("%d", bit );     }
-       printf("\n");   
-       
-       free(output);
 }
 
 float complex cexpf (float complex Z)