From 32efb41613abc7931721a7015228b662181054e2 Mon Sep 17 00:00:00 2001
From: Ahmet Inan <xdsopl@googlemail.com>
Date: Sun, 7 Dec 2014 18:14:37 +0100
Subject: [PATCH] added "gray" area between data and control signal to improve
 sync detection

---
 app/src/main/rs/calibration_detector.rsh |  7 +++----
 app/src/main/rs/decoder.rs               | 11 ++++++-----
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/app/src/main/rs/calibration_detector.rsh b/app/src/main/rs/calibration_detector.rsh
index e4eed55..b600f09 100644
--- a/app/src/main/rs/calibration_detector.rsh
+++ b/app/src/main/rs/calibration_detector.rsh
@@ -20,12 +20,11 @@ limitations under the License.
 #include "constants.rsh"
 #include "state.rsh"
 
-static int calibration_detected(float dat_value, int cnt_active, int cnt_quantized)
+static int calibration_detected(float dat_value, int dat_active, int cnt_active, int cnt_quantized)
 {
     static int progress, countdown;
     static int leader_counter, break_counter;
 
-    int dat_active = !cnt_active;
     progress = countdown ? progress : 0;
     countdown -= !!countdown;
 
@@ -99,9 +98,9 @@ static int calibration_detected(float dat_value, int cnt_active, int cnt_quantiz
     return -1;
 }
 
-static int calibration_detector(float dat_value, int cnt_active, int cnt_quantized)
+static int calibration_detector(float dat_value, int dat_active, int cnt_active, int cnt_quantized)
 {
-    switch (calibration_detected(dat_value, cnt_active, cnt_quantized)) {
+    switch (calibration_detected(dat_value, dat_active, cnt_active, cnt_quantized)) {
         case 0x88:
             return mode_robot36;
         case 0x0c:
diff --git a/app/src/main/rs/decoder.rs b/app/src/main/rs/decoder.rs
index f11a3eb..2e951b0 100644
--- a/app/src/main/rs/decoder.rs
+++ b/app/src/main/rs/decoder.rs
@@ -130,10 +130,11 @@ void decode(int samples) {
         float cnt_value = demodulate(&cnt_fmd, cnt_baseband);
         float dat_value = demodulate(&dat_fmd, dat_baseband);
 
-        int cnt_active = cabs(dat_baseband) < cabs(cnt_baseband);
-        uchar cnt_level = save_cnt ? 127.5f - 127.5f * cnt_value : 0.0f;
-        uchar dat_level = save_dat ? 127.5f + 127.5f * dat_value : 0.0f;
-        value_buffer[hpos + even_hpos] = cnt_active ? cnt_level : dat_level;
+        int cnt_active = cabs(dat_baseband) < 4.0f * cabs(cnt_baseband);
+        int dat_active = cabs(cnt_baseband) < 4.0f * cabs(dat_baseband);
+        uchar cnt_level = save_cnt && cnt_active ? 127.5f - 127.5f * cnt_value : 0.0f;
+        uchar dat_level = save_dat && dat_active ? 127.5f + 127.5f * dat_value : 0.0f;
+        value_buffer[hpos + even_hpos] = cnt_level | dat_level;
 
         int cnt_quantized = round(cnt_value);
         int dat_quantized = round(dat_value);
@@ -143,7 +144,7 @@ void decode(int samples) {
         sync_counter = sync_level ? sync_counter + 1 : 0;
 
         if (*current_mode != mode_raw) {
-            int detected_mode = calibration_detector(dat_value, cnt_active, cnt_quantized);
+            int detected_mode = calibration_detector(dat_value, dat_active, cnt_active, cnt_quantized);
             if (detected_mode >= 0)
                 reset();
             switch_mode(detected_mode);