From 3bc66a96fe60139015ddaa0b8fb12259675ff897 Mon Sep 17 00:00:00 2001
From: marshmellow42 <marshmellowrf@gmail.com>
Date: Sat, 21 Feb 2015 22:54:52 -0500
Subject: [PATCH] added PSK2 to lf simpsk

testing still ongoing.
---
 client/cmdlf.c   | 12 ++++++++++--
 common/lfdemod.c | 17 +++++++++++++++++
 common/lfdemod.h |  1 +
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/client/cmdlf.c b/client/cmdlf.c
index b2372101..d3ea8eea 100644
--- a/client/cmdlf.c
+++ b/client/cmdlf.c
@@ -28,6 +28,7 @@
 #include "cmdlft55xx.h"
 #include "cmdlfpcf7931.h"
 #include "cmdlfio.h"
+#include "lfdemod.h"
 
 static int CmdHelp(const char *Cmd);
 
@@ -853,13 +854,20 @@ int CmdLFpskSim(const char *Cmd)
   }
   if (dataLen == 0){ //using DemodBuffer
     if (clk==0) clk = GetPskClock(NULL, FALSE, FALSE);
-    if (!carrier) carrier = GetPskCarrier(NULL, FALSE, FALSE);
+    if (!carrier) carrier = GetPskCarrier(NULL, FALSE, FALSE); 
   } else {
     setDemodBuf(data, dataLen, 0);
   }
   if (clk <= 0) clk = 32;
   if (carrier == 0) carrier = 2;
-
+  if (pskType != 1){
+    if (pskType == 2){
+      //need to convert psk2 to psk1 data before sim
+      psk2TOpsk1(DemodBuffer, DemodBufferLen);
+    } else {
+      PrintAndLog("Sorry, PSK3 not yet available");
+    }
+  }
   uint16_t arg1, arg2;
   arg1 = clk << 8 | carrier;
   arg2 = invert;
diff --git a/common/lfdemod.c b/common/lfdemod.c
index 79252dd9..bee87ece 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -1068,6 +1068,23 @@ void psk1TOpsk2(uint8_t *BitStream, size_t size)
 	return;
 }
 
+// by marshmellow
+// convert psk2 demod to psk1 demod
+// from only transition waves are 1s to phase shifts change bit
+void psk2TOpsk1(uint8_t *BitStream, size_t size)
+{
+	size_t i;
+	uint8_t phase=BitStream[0];
+	//uint8_t lastBit=BitStream[0];
+	for (i=1; i<size; i++){
+		if (phase!=BitStream[i]){
+			phase ^=1;
+		}
+		BitStream[i]=phase;
+	}
+	return;
+}
+
 // redesigned by marshmellow adjusted from existing decode functions
 // indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
diff --git a/common/lfdemod.h b/common/lfdemod.h
index 2880ff82..9d55d064 100644
--- a/common/lfdemod.h
+++ b/common/lfdemod.h
@@ -28,6 +28,7 @@ int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t
 uint32_t bytebits_to_byte(uint8_t* src, size_t numbits);
 int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert, int maxErr);
 void psk1TOpsk2(uint8_t *BitStream, size_t size);
+void psk2TOpsk1(uint8_t *BitStream, size_t size);
 int DetectNRZClock(uint8_t dest[], size_t size, int clock);
 int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert);
 void pskCleanWave(uint8_t *bitStream, size_t size);
-- 
2.39.2