From 988b912d3c1352fcc1e383fce50cfb90f84b87c2 Mon Sep 17 00:00:00 2001
From: John Greb <hexameron@spam.no>
Date: Thu, 5 Feb 2015 19:38:46 +0000
Subject: [PATCH] Big Endian.

---
 plugins/channel/lora/lorabits.h      | 28 ++++++++++++++++++++++++++++
 plugins/channel/lora/lorademod.cpp   | 10 ++++++----
 plugins/channel/lora/lorademod.h     |  3 +++
 plugins/channel/lora/lorademodgui.ui |  4 ++--
 4 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/plugins/channel/lora/lorabits.h b/plugins/channel/lora/lorabits.h
index 046d6a0ce..7c53b4fda 100644
--- a/plugins/channel/lora/lorabits.h
+++ b/plugins/channel/lora/lorabits.h
@@ -23,3 +23,31 @@ short LoRaDemod::toGray(short num)
         return (num >> 1) ^ num;
 }
 
+// ignore FEC, data in lsb
+void LoRaDemod::hamming(char* inout, int size)
+{
+	int i;
+	char c;
+	for (i = 0; i < size; i++) {
+		c = inout[i];
+		c = ((c&1)<<3) | ((c&2)<<1) | ((c&4)>>1) | ((c&8)>>3);
+		inout[i] = c;
+	}
+	inout[i] = 0;
+}
+
+// data whitening
+void LoRaDemod::prng(char* inout, int size)
+{
+	const char otp[] = {
+	"                                                                                                                                                                              "
+	};
+	int i, maxchars;
+
+	maxchars = sizeof( otp );
+	if (size < maxchars)
+		maxchars = size;
+	for (i = 0; i < maxchars; i++)
+		inout[i] ^= otp[i] - 32;
+}
+
diff --git a/plugins/channel/lora/lorademod.cpp b/plugins/channel/lora/lorademod.cpp
index 194b940b5..8ffa9f3c4 100644
--- a/plugins/channel/lora/lorademod.cpp
+++ b/plugins/channel/lora/lorademod.cpp
@@ -75,8 +75,8 @@ void LoRaDemod::dumpRaw()
 {
 	short bin, j, max;
 	max = m_time / 4 - 3;
-	if (max > 36)
-		max = 36;
+	if (max > 80)
+		max = 80; // 80 symbols is  about 40 chars
 	char text[256];
 	for ( j=0; j < max; j++) {
 		bin = (history[j * 4 + 12] + m_tune ) & (LORA_SFFT_LEN - 1);
@@ -84,10 +84,12 @@ void LoRaDemod::dumpRaw()
 	}
 	for ( j=0; j < max; j+=6)
 		interleave(&text[j]);
+	prng(text, max); // ??
+	hamming(text, max);
 	for ( j=0; j < max; j++)
-		text[j] += 32;
+		text[j] += 64; // 4 bits per symbol
 	text[j] = 0;
-	printf(">%s..(%d)\n", text, m_time / 4 - 2);
+	printf(">%s<\n", text);
 }
 
 short LoRaDemod::synch(short bin)
diff --git a/plugins/channel/lora/lorademod.h b/plugins/channel/lora/lorademod.h
index 3675a850d..312ae66d0 100644
--- a/plugins/channel/lora/lorademod.h
+++ b/plugins/channel/lora/lorademod.h
@@ -48,6 +48,9 @@ private:
 	void dumpRaw(void);
 	short synch (short bin);
 	short toGray(short bin);
+	void hamming(char* inout, int size);
+	void prng(char* inout, int size);
+
 	class MsgConfigureLoRaDemod : public Message {
 		MESSAGE_CLASS_DECLARATION
 
diff --git a/plugins/channel/lora/lorademodgui.ui b/plugins/channel/lora/lorademodgui.ui
index 7f3eedebf..068f86aae 100644
--- a/plugins/channel/lora/lorademodgui.ui
+++ b/plugins/channel/lora/lorademodgui.ui
@@ -71,7 +71,7 @@
        <number>0</number>
       </property>
       <property name="maximum">
-       <number>1</number>
+       <number>2</number>
       </property>
       <property name="pageStep">
        <number>1</number>
@@ -109,7 +109,7 @@
        </size>
       </property>
       <property name="text">
-       <string>2^8</string>
+       <string>6:4 2^8</string>
       </property>
       <property name="alignment">
        <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>