From 4469412e88d37b988729fed47c6bc21d98cc6e88 Mon Sep 17 00:00:00 2001
From: iceman1001 <iceman@iuse.se>
Date: Sun, 14 Feb 2016 11:58:25 +0100
Subject: [PATCH] ADD:  adding a presco demod, given 0x10D as preamble,  .. 
 *work in progress*

---
 client/cmdlfpresco.c | 39 ++++++++++++++++++++++++++++++++-------
 common/lfdemod.c     | 14 ++++++++++++++
 common/lfdemod.h     |  1 +
 3 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/client/cmdlfpresco.c b/client/cmdlfpresco.c
index 4986071c..e6ac19e4 100644
--- a/client/cmdlfpresco.c
+++ b/client/cmdlfpresco.c
@@ -74,19 +74,44 @@ int GetPrescoBits(uint32_t sitecode, uint32_t usercode, uint8_t	*prescoBits) {
 	if (bitLen != 88) return 0;
 	return 1;
 }
+//see ASKDemod for what args are accepted
+int CmdPrescoDemod(const char *Cmd) {
+	if (!ASKDemod(Cmd, false, false, 1)) {
+		if (g_debugMode) PrintAndLog("ASKDemod failed");
+		return 0;
+	}
+	size_t size = DemodBufferLen;
+	//call lfdemod.c demod for Viking
+	int ans = PrescoDemod(DemodBuffer, &size);
+	if (ans < 0) {
+		if (g_debugMode) PrintAndLog("Error Presco_Demod %d", ans);
+		return 0;
+	}
+	//got a good demod
+	uint32_t raw1 = bytebits_to_byte(DemodBuffer+ans, 32);
+	uint32_t raw2 = bytebits_to_byte(DemodBuffer+ans+32, 32);
+	uint32_t cardid = bytebits_to_byte(DemodBuffer+ans+24, 32);
+	PrintAndLog("Presco Tag Found: Card ID %08X", cardid);
+	PrintAndLog("Raw: %08X%08X", raw1,raw2);
+	setDemodBuf(DemodBuffer+ans, 64, 0);
+	
+	// uint32_t sitecode = 0, usercode = 0;
+	// GetWiegandFromPresco(id, &sitecode, &usercode);
+	// PrintAndLog8("SiteCode %d  |  UserCode %d", sitecode, usercode);
+	
+	return 1;
+}
 
 //see ASKDemod for what args are accepted
 int CmdPrescoRead(const char *Cmd) {
-	PrintAndLog("Number: 123456789 --> Sitecode 30 | usercode 8665");
-//	GetWiegandFromPresco("123456789");
+	//	Presco Number: 123456789 --> Sitecode 30 | usercode 8665
 
 	// read lf silently
-	//CmdLFRead("s");
+	CmdLFRead("s");
 	// get samples silently
-	//getSamples("30000",false);
-	// demod and output viking ID	
-	//return CmdVikingDemod(Cmd);
-	return 0;
+	getSamples("30000",false);
+	// demod and output Presco ID	
+	return CmdPrescoDemod(Cmd);
 }
 
 int CmdPrescoClone(const char *Cmd) {
diff --git a/common/lfdemod.c b/common/lfdemod.c
index 23b9c8b5..967a98a8 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -677,6 +677,20 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) {
 	return (int) startIdx;
 }
 
+// find presco preamble 0x10D in already demoded data
+int PrescoDemod(uint8_t *dest, size_t *size) {
+	//make sure buffer has data
+	if (*size < 64*2) return -2;
+
+	size_t startIdx = 0;
+	uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
+	uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+	if (errChk == 0) return -4; //preamble not found
+	//return start position
+	return (int) startIdx;
+}
+
+
 // Ask/Biphase Demod then try to locate an ISO 11784/85 ID
 // BitStream must contain previously askrawdemod and biphasedemoded data
 int FDXBdemodBI(uint8_t *dest, size_t *size)
diff --git a/common/lfdemod.h b/common/lfdemod.h
index a1d99e11..f4ed9107 100644
--- a/common/lfdemod.h
+++ b/common/lfdemod.h
@@ -53,5 +53,6 @@ int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert);
 int ParadoxdemodFSK(uint8_t *dest, size_t *size, uint32_t *hi2, uint32_t *hi, uint32_t *lo);
 int PyramiddemodFSK(uint8_t *dest, size_t *size);
 int VikingDemod_AM(uint8_t *dest, size_t *size);
+int PrescoDemod(uint8_t *dest, size_t *size);
 
 #endif
-- 
2.39.2