Improved algorithm for keeping track of active satellites

openrtx/include/interfaces/graphics.h

@@ -267,8 +267,9 @@ void gfx_drawSmeter(point_t start, uint16_t width, uint16_t height, float rssi,
  * @param width: Bar graph width
  * @param height: Bar graph height
  * @param sats: pointer to the array of satellites data
+ * @param active_sats: bitset representing which sats are part of the fix
  */
-void gfx_drawGPSgraph(point_t start, uint16_t width, uint16_t height, sat_t *sats);
+void gfx_drawGPSgraph(point_t start, uint16_t width, uint16_t height, sat_t *sats, uint16_t active_sats);
 
 /**
  * Function to draw a compass of arbitrary size.

openrtx/include/state.h

@@ -35,7 +35,6 @@ typedef struct
     uint8_t elevation;    // Elevation in degrees
     uint16_t azimuth;     // Azimuth in degrees
     uint8_t snr;          // Quality of the signal in range 0-99
-    bool active;          // True if this satellite is part of the fix
 }
 sat_t;
 
@@ -50,6 +49,7 @@ typedef struct
     uint8_t satellites_tracked; // Number of tracked satellites
     uint8_t satellites_in_view; // Satellites in view
     sat_t satellites[12]; // Details about satellites in view
+    uint16_t active_sats; // Bitmap representing which sats are part of the fix
     float latitude;       // Latitude coordinates
     float longitude;      // Longitude coordinates
     float altitude;       // Antenna altitude above mean sea level (geoid) in m

openrtx/src/gps.c

@@ -58,6 +58,7 @@ void gps_taskFunc(char *line, int len, gps_t *state)
 
         case MINMEA_SENTENCE_GSA:
         {
+            state->active_sats = 0;
             struct minmea_sentence_gsa frame;
             if (minmea_parse_gsa(&frame, line))
             {
@@ -66,14 +67,7 @@ void gps_taskFunc(char *line, int len, gps_t *state)
                 {
                     if (frame.sats[i] != 0)
                     {
-                        for (int j = 0; j < 12; j++)
+                        state->active_sats |= 1 << frame.sats[i];
-                        {
-                            if (state->satellites[j].id == frame.sats[i])
-                            {
-                                state->satellites[j].active = true;
-                                break;
-                            }
-                        }
                     }
                 }
             }
@@ -92,7 +86,6 @@ void gps_taskFunc(char *line, int len, gps_t *state)
                     state->satellites[index].elevation = frame.sats[i].elevation;
                     state->satellites[index].azimuth = frame.sats[i].azimuth;
                     state->satellites[index].snr = frame.sats[i].snr;
-                    state->satellites[index].active = false;
                 }
                 // Zero out unused satellite slots
                 if (frame.msg_nr == frame.total_msgs && frame.total_msgs < 3)

openrtx/src/graphics.c

@@ -641,7 +641,8 @@ void gfx_drawSmeter(point_t start, uint16_t width, uint16_t height, float rssi,
 void gfx_drawGPSgraph(point_t start,
                       uint16_t width,
                       uint16_t height,
-                      sat_t *sats)
+                      sat_t *sats,
+                      uint16_t active_sats)
 {
     color_t white =  {255, 255, 255, 255};
     color_t yellow = {250, 180, 19 , 255};
@@ -655,11 +656,11 @@ void gfx_drawGPSgraph(point_t start,
         bar_height = (height - 8) * sats[i].snr / 100 + 1;
         point_t bar_pos = {start.x + 2 + i * (bar_width + 2),
                            start.y + (height - 8) - bar_height};
-        color_t bar_color = (sats[i].active) ? yellow : white;
+        color_t bar_color = (active_sats & 1 << sats[i].id) ? yellow : white;
         gfx_drawRect(bar_pos, bar_width, bar_height, bar_color, true);
         snprintf(id_buf, 5, "%2d ", sats[i].id);
         point_t id_pos = {bar_pos.x, start.y + height};
-        gfx_print(id_pos, id_buf, FONT_SIZE_5PT, TEXT_ALIGN_LEFT, white);
+        gfx_print(id_pos, id_buf, FONT_SIZE_5PT, TEXT_ALIGN_LEFT, bar_color);
     }
     uint8_t bars_width = 9 + 11 * (bar_width + 2);
     point_t left_line_end = {start.x, start.y + height - 9};
@@ -683,19 +684,20 @@ void gfx_drawGPScompass(point_t start,
     gfx_drawCircle(circle_pos, radius, white);
     point_t n_box = {start.x + radius - 5, start.y};
     gfx_drawRect(n_box, 13, 13, black, true);
+    float needle_radius = radius - 4;
     if (active)
     {
         // Needle
         deg = -deg;
         deg -= 90.0f;
-        point_t p1 = {circle_pos.x + radius * COS(deg),
+        point_t p1 = {circle_pos.x + needle_radius * COS(deg),
-                      circle_pos.y + radius * SIN(deg)};
+                      circle_pos.y + needle_radius * SIN(deg)};
-        point_t p2 = {circle_pos.x + radius * COS(deg + 145.0f),
+        point_t p2 = {circle_pos.x + needle_radius * COS(deg + 145.0f),
-                      circle_pos.y + radius * SIN(deg + 145.0f)};
+                      circle_pos.y + needle_radius * SIN(deg + 145.0f)};
-        point_t p3 = {circle_pos.x + radius / 2 * COS(deg + 180.0f),
+        point_t p3 = {circle_pos.x + needle_radius / 2 * COS(deg + 180.0f),
-                      circle_pos.y + radius / 2 * SIN(deg + 180.0f)};
+                      circle_pos.y + needle_radius / 2 * SIN(deg + 180.0f)};
-        point_t p4 = {circle_pos.x + radius * COS(deg - 145.0f),
+        point_t p4 = {circle_pos.x + needle_radius * COS(deg - 145.0f),
-                      circle_pos.y + radius * SIN(deg - 145.0f)};
+                      circle_pos.y + needle_radius * SIN(deg - 145.0f)};
         gfx_drawLine(p1, p2, yellow);
         gfx_drawLine(p2, p3, yellow);
         gfx_drawLine(p3, p4, yellow);

openrtx/src/ui/ui_menu.c

@@ -316,7 +316,8 @@ void _ui_drawMenuGPS(ui_state_t* ui_state)
     gfx_drawGPSgraph(bar_pos,
                      (SCREEN_WIDTH * 2 / 3) - layout.horizontal_pad,
                      SCREEN_HEIGHT / 3,
-                     last_state.gps_data.satellites);
+                     last_state.gps_data.satellites,
+                     last_state.gps_data.active_sats);
 }
 
 void _ui_drawMenuSettings(ui_state_t* ui_state)