From 70f0ce45d336f7bd856f215d2244db36315d8915 Mon Sep 17 00:00:00 2001
From: Marco <49691247+marcoSchr@users.noreply.github.com>
Date: Sun, 31 Mar 2024 15:30:15 +0200
Subject: [PATCH] GPS: using 16-bit integers for course over ground

---
 openrtx/include/core/gps.h          |  4 ++--
 openrtx/src/core/gps.c              |  4 ++--
 openrtx/src/core/voicePromptUtils.c |  4 ++--
 openrtx/src/ui/default/ui.c         | 11 +++++------
 4 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/openrtx/include/core/gps.h b/openrtx/include/core/gps.h
index 448058d3..73be489e 100644
--- a/openrtx/include/core/gps.h
+++ b/openrtx/include/core/gps.h
@@ -52,8 +52,8 @@ typedef struct
     int32_t    longitude;            // Longitude coordinates
     int16_t    altitude;             // Antenna altitude above mean sea level (geoid) in m
     uint16_t   speed;                // Ground speed in km/h
-    float      tmg_mag;              // Course over ground, degrees, magnetic
-    float      tmg_true;             // Course over ground, degrees, true
+    int16_t    tmg_mag;              // Course over ground, degrees, magnetic
+    int16_t    tmg_true;             // Course over ground, degrees, true
 }
 gps_t;
 
diff --git a/openrtx/src/core/gps.c b/openrtx/src/core/gps.c
index af4ad891..54934968 100644
--- a/openrtx/src/core/gps.c
+++ b/openrtx/src/core/gps.c
@@ -167,8 +167,8 @@ void gps_task()
             if (minmea_parse_vtg(&frame, sentence))
             {
                 gps_data.speed = minmea_toint(&frame.speed_kph);
-                gps_data.tmg_mag = minmea_tofloat(&frame.magnetic_track_degrees);
-                gps_data.tmg_true = minmea_tofloat(&frame.true_track_degrees);
+                gps_data.tmg_mag = minmea_toint(&frame.magnetic_track_degrees);
+                gps_data.tmg_true = minmea_toint(&frame.true_track_degrees);
             }
         }
         break;
diff --git a/openrtx/src/core/voicePromptUtils.c b/openrtx/src/core/voicePromptUtils.c
index f18b7d9b..a0c9cadb 100644
--- a/openrtx/src/core/voicePromptUtils.c
+++ b/openrtx/src/core/voicePromptUtils.c
@@ -550,7 +550,7 @@ void vp_announceM17Info(const channel_t* channel, bool isEditing,
 
 static bool IsCompassCloseEnoughToCardinalPoint()
 {
-    float tmg_true = state.gps_data.tmg_true;
+    int16_t tmg_true = state.gps_data.tmg_true;
 
     return (tmg_true < (0   + margin) || tmg_true > (360 - margin)) || // north
            (tmg_true > (90  - margin) && tmg_true < (90  + margin)) || // east
@@ -638,7 +638,7 @@ void vp_announceGPSInfo(vpGPSInfoFlags_t gpsInfoFlags)
         vp_queuePrompt(PROMPT_COMPASS);
         if (!IsCompassCloseEnoughToCardinalPoint())
         {
-            sniprintf(buffer, 16, "%3.1f", state.gps_data.tmg_true);
+            sniprintf(buffer, 16, "%d", state.gps_data.tmg_true);
             vp_queueString(buffer, vpAnnounceCommonSymbols);
             vp_queuePrompt(PROMPT_DEGREES);
         }
diff --git a/openrtx/src/ui/default/ui.c b/openrtx/src/ui/default/ui.c
index e219a684..0a51604d 100644
--- a/openrtx/src/ui/default/ui.c
+++ b/openrtx/src/ui/default/ui.c
@@ -1272,10 +1272,10 @@ void ui_saveState()
 #ifdef CONFIG_GPS
 static uint16_t priorGPSSpeed = 0;
 static int16_t  priorGPSAltitude = 0;
-static float  priorGPSDirection = 500; // impossible value init.
-static uint8_t priorGPSFixQuality= 0;
-static uint8_t priorGPSFixType = 0;
-static uint8_t    priorSatellitesInView = 0;
+static int16_t  priorGPSDirection = 500; // impossible value init.
+static uint8_t  priorGPSFixQuality= 0;
+static uint8_t  priorGPSFixType = 0;
+static uint8_t  priorSatellitesInView = 0;
 static uint32_t vpGPSLastUpdate = 0;
 
 static vpGPSInfoFlags_t GetGPSDirectionOrSpeedChanged()
@@ -1313,8 +1313,7 @@ static vpGPSInfoFlags_t GetGPSDirectionOrSpeedChanged()
         priorGPSAltitude = state.gps_data.altitude;
     }
 
-    float degreeDiff = fabs(state.gps_data.tmg_true - priorGPSDirection);
-    if (degreeDiff  >= 1)
+    if (state.gps_data.tmg_true != priorGPSDirection)
     {
         whatChanged |= vpGPSDirection;
         priorGPSDirection = state.gps_data.tmg_true;