Synchronized minor FPGA orphaned change

In file hi_iso14443a.v from fpga-xc3s100e to fpga-xc2s30 and rebuilt the FPGA bitstream files for the Spartan-2

CHANGELOG.md

@@ -3,6 +3,8 @@ All notable changes to this project will be documented in this file.
 This project uses the changelog in accordance with [keepchangelog](http://keepachangelog.com/). Please use this to write notable changes, which is not the same as git commit log...
 
 ## [unreleased][unreleased]
+ - Rebuilt the Spartan-2 `fpga_*.bit` files to include the `hi_iso14443a.v` update (@d18c7db)
+ - Added minor orphaned change from `hi_iso14443a.v` in `fpga-xc3s100e` to `hi_iso14443a.v` in `fpga-xc2s30` (@d18c7db)
  - Added python3 script to convert amiibo nfc Flipper Zero files to eml files to be used with Proxmark3 (@OscarAkaElvis)
  - Changed `hf mf restore` - Auth both key A and key B with default password (@wh201906)
  - Changed `nfc decode -f` - now can detect and convert MFC dumpfiles to NDEF byte arrays (@iceman1001)

fpga-xc2s30/hi_iso14443a.v

@@ -222,17 +222,29 @@ reg signed [10:0] rx_mod_falling_edge_max;
 reg signed [10:0] rx_mod_rising_edge_max;
 reg curbit;
 
-`define EDGE_DETECT_THRESHOLD   5
+`define EDGE_DETECT_THRESHOLD   3
+`define EDGE_DETECT_THRESHOLDHIGH   20
 
 always @(negedge adc_clk)
 begin
     if(negedge_cnt[3:0] == mod_detect_reset_time)
+    begin
+          if (mod_type == `FPGA_HF_ISO14443A_SNIFFER)
+          begin
+              // detect modulation signal: if modulating, there must have been a falling AND a rising edge
+              if ((rx_mod_falling_edge_max > `EDGE_DETECT_THRESHOLDHIGH) && (rx_mod_rising_edge_max < -`EDGE_DETECT_THRESHOLDHIGH))
+                  curbit <= 1'b1; // modulation
+              else
+                  curbit <= 1'b0; // no modulation
+          end
+          else
           begin
               // detect modulation signal: if modulating, there must have been a falling AND a rising edge
               if ((rx_mod_falling_edge_max > `EDGE_DETECT_THRESHOLD) && (rx_mod_rising_edge_max < -`EDGE_DETECT_THRESHOLD))
                   curbit <= 1'b1; // modulation
               else
                   curbit <= 1'b0; // no modulation
+          end
         // reset modulation detector
         rx_mod_rising_edge_max <= 0;
         rx_mod_falling_edge_max <= 0;