altos: Make APRS format (compressed/uncompressed) configurable

[fw/altos] / src / drivers / ao_aprs.c

diff --git a/src/drivers/ao_aprs.c b/src/drivers/ao_aprs.c
index 19beb78f2b51dbf89f1f0f44563d50b203357bc2..2e977612809ddbe4c41333486e85f25f3aa0f569 100644 (file)
--- a/src/drivers/ao_aprs.c
+++ b/src/drivers/ao_aprs.c
@@ -707,8 +707,7 @@ static int tncPositionPacket(void)
     static int32_t     latitude;
     static int32_t     longitude;
     static int32_t     altitude;
-    int32_t            lat, lon, alt;
-    uint8_t    *buf;
+    uint8_t            *buf;
 
     if (ao_gps_data.flags & AO_GPS_VALID) {
        latitude = ao_gps_data.latitude;
@@ -719,28 +718,93 @@ static int tncPositionPacket(void)
     }
 
     buf = tncBuffer;
-    *buf++ = '!';
 
-    /* Symbol table ID */
-    *buf++ = '/';
+    switch (ao_config.aprs_format) {
+    case AO_APRS_FORMAT_COMPRESSED:
+    default:
+    {
+           int32_t             lat, lon, alt;
+
+           *buf++ = '!';
+
+           /* Symbol table ID */
+           *buf++ = '/';
+
+           lat = ((uint64_t) 380926 * (900000000 - latitude)) / 10000000;
+           lon = ((uint64_t) 190463 * (1800000000 + longitude)) / 10000000;
+
+           alt = ao_aprs_encode_altitude(altitude);
+
+           tncCompressInt(buf, lat, 4);
+           buf += 4;
+           tncCompressInt(buf, lon, 4);
+           buf += 4;
 
-    lat = ((uint64_t) 380926 * (900000000 - latitude)) / 10000000;
-    lon = ((uint64_t) 190463 * (1800000000 + longitude)) / 10000000;
+           /* Symbol code */
+           *buf++ = '\'';
 
-    alt = ao_aprs_encode_altitude(altitude);
+           tncCompressInt(buf, alt, 2);
+           buf += 2;
 
-    tncCompressInt(buf, lat, 4);
-    buf += 4;
-    tncCompressInt(buf, lon, 4);
-    buf += 4;
+           *buf++ = 33 + ((1 << 5) | (2 << 3));
 
-    /* Symbol code */
-    *buf++ = '\'';
+           break;
+    }
+    case AO_APRS_FORMAT_UNCOMPRESSED:
+    {
+           char        lat_sign = 'N', lon_sign = 'E';
+           int32_t     lat = latitude;
+           int32_t     lon = longitude;
+           int32_t     alt = altitude;
+           uint16_t    lat_deg;
+           uint16_t    lon_deg;
+           uint16_t    lat_min;
+           uint16_t    lat_frac;
+           uint16_t    lon_min;
+           uint16_t    lon_frac;
+
+           if (lat < 0) {
+                   lat_sign = 'S';
+                   lat = -lat;
+           }
 
-    tncCompressInt(buf, alt, 2);
-    buf += 2;
+           if (lon < 0) {
+                   lon_sign = 'W';
+                   lon = -lon;
+           }
 
-    *buf++ = 33 + ((1 << 5) | (2 << 3));
+           /* Round latitude and longitude by 0.005 minutes */
+           lat = lat + 833;
+           if (lat > 900000000)
+                   lat = 900000000;
+           lon = lon + 833;
+           if (lon > 1800000000)
+                   lon = 1800000000;
+
+           lat_deg = lat / 10000000;
+           lat -= lat_deg * 10000000;
+           lat *= 60;
+           lat_min = lat / 10000000;
+           lat -= lat_min * 10000000;
+           lat_frac = lat / 100000;
+
+           lon_deg = lon / 10000000;
+           lon -= lon_deg * 10000000;
+           lon *= 60;
+           lon_min = lon / 10000000;
+           lon -= lon_min * 10000000;
+           lon_frac = lon / 100000;
+
+           /* Convert from meters to feet */
+           alt = (alt * 328 + 50) / 100;
+
+           buf += sprintf((char *) tncBuffer, "!%02u%02u.%02u%c/%03u%02u.%02u%c'/A=%06u ",
+                          lat_deg, lat_min, lat_frac, lat_sign,
+                          lon_deg, lon_min, lon_frac, lon_sign,
+                          alt);
+           break;
+    }
+    }
 
     buf += tncComment(buf);