Cast M10SPG altitude to float

src/collectors/m10spg_clctr.c

@@ -16,6 +16,7 @@ typedef struct {
         int32_t I32;   /**< The message payload, interpreted as a int32_t */
         uint8_t U8;    /**< The message payload, interpreted as a uint8_t */
         vec2d_t VEC2D; /**< The message payload, interpreted as a vec2d_t */
+        float FLOAT;   /**< The message payload, interpreted as a float */
     };
 } __attribute__((packed)) message_t;
 
@@ -76,7 +77,7 @@ void *m10spg_collector(void *args) {
                 fprintf(stderr, "M10SPG couldn't send message: %s.\n", strerror(errno));
             }
             msg.type = TAG_ALTITUDE_SEA;
-            msg.I32 = buf.pos.hMSL;
+            msg.FLOAT = ((float)buf.pos.hMSL / ALT_SCALE_TO_METERS);
             if (mq_send(sensor_q, (char *)&msg, sizeof(msg), 0) == -1) {
                 fprintf(stderr, "M10SPG couldn't send message: %s.\n", strerror(errno));
             }

src/drivers/m10spg/ubx_def.h

@@ -87,9 +87,14 @@ typedef struct {
     uint32_t vAcc;  /**< Vertical accuracy measurement in millimeters */
 } UBXNavPositionPayload;
 
-/** A conversion constant to go from the scale of the UBX lat/lon (1E-7deg) to regular degrees */
-#define LAT_SCALE_TO_DEGREES 10000000
-#define LON_SCALE_TO_DEGREES 10000000
+/** A conversion constant to go from the scale of UBX latitude (1E-7deg) to regular degrees */
+#define LAT_SCALE_TO_DEGREES 1e7f
+
+/** A conversion constant to go from the scale of UBX longitude (1E-7deg) to regular degrees */
+#define LON_SCALE_TO_DEGREES 1e7f
+
+/** A conversion constant to go from the scale of UBX altitude (mm) to meters */
+#define ALT_SCALE_TO_METERS 1e3f
 
 /** A struct representing the UBX-NAV-VELNED (velocity) payload */
 typedef struct {