altos: Restructure skytraq NMEA parsing code to save some space
authorAnthony Towns <aj@erisian.com.au>
Sun, 16 Jan 2011 00:54:45 +0000 (10:54 +1000)
committerKeith Packard <keithp@keithp.com>
Sun, 16 Jan 2011 22:34:54 +0000 (14:34 -0800)
Splitting this into several smaller functions appears to make SDCC
generate better code.

src/ao_gps_skytraq.c

index 2d3d464c881fa79342cfc1b3b79e5da203ce9386..a2d5f1dbe9cd9e988e5851fada1211a815ace17b 100644 (file)
@@ -180,6 +180,215 @@ ao_gps_parse_flag(char no_c, char yes_c) __reentrant
        return ret;
 }
 
+static void
+ao_nmea_gga()
+{
+       uint8_t i;
+
+       /* Now read the data into the gps data record
+        *
+        * $GPGGA,025149.000,4528.1723,N,12244.2480,W,1,05,2.0,103.5,M,-19.5,M,,0000*66
+        *
+        * Essential fix data
+        *
+        *         025149.000   time (02:51:49.000 GMT)
+        *         4528.1723,N  Latitude 45°28.1723' N
+        *         12244.2480,W Longitude 122°44.2480' W
+        *         1            Fix quality:
+        *                                 0 = invalid
+        *                                 1 = GPS fix (SPS)
+        *                                 2 = DGPS fix
+        *                                 3 = PPS fix
+        *                                 4 = Real Time Kinematic
+        *                                 5 = Float RTK
+        *                                 6 = estimated (dead reckoning)
+        *                                 7 = Manual input mode
+        *                                 8 = Simulation mode
+        *         05           Number of satellites (5)
+        *         2.0          Horizontal dilution
+        *         103.5,M              Altitude, 103.5M above msl
+        *         -19.5,M              Height of geoid above WGS84 ellipsoid
+        *         ?            time in seconds since last DGPS update
+        *         0000         DGPS station ID
+        *         *66          checksum
+        */
+
+       ao_gps_next_tick = ao_time();
+       ao_gps_next.flags = AO_GPS_RUNNING | ao_gps_date_flags;
+       ao_gps_next.hour = ao_gps_decimal(2);
+       ao_gps_next.minute = ao_gps_decimal(2);
+       ao_gps_next.second = ao_gps_decimal(2);
+       ao_gps_skip_field();    /* skip seconds fraction */
+
+       ao_gps_next.latitude = ao_gps_parse_pos(2);
+       if (ao_gps_parse_flag('N', 'S'))
+               ao_gps_next.latitude = -ao_gps_next.latitude;
+       ao_gps_next.longitude = ao_gps_parse_pos(3);
+       if (ao_gps_parse_flag('E', 'W'))
+               ao_gps_next.longitude = -ao_gps_next.longitude;
+
+       i = ao_gps_decimal(0xff);
+       if (i == 1)
+               ao_gps_next.flags |= AO_GPS_VALID;
+
+       i = ao_gps_decimal(0xff) << AO_GPS_NUM_SAT_SHIFT;
+       if (i > AO_GPS_NUM_SAT_MASK)
+               i = AO_GPS_NUM_SAT_MASK;
+       ao_gps_next.flags |= i;
+
+       ao_gps_lexchar();
+       ao_gps_next.hdop = ao_gps_decimal(0xff);
+       if (ao_gps_next.hdop <= 50) {
+               ao_gps_next.hdop = (uint8_t) 5 * ao_gps_next.hdop;
+               if (ao_gps_char == '.')
+                       ao_gps_next.hdop = (ao_gps_next.hdop +
+                                           ((uint8_t) ao_gps_decimal(1) >> 1));
+       } else
+               ao_gps_next.hdop = 255;
+       ao_gps_skip_field();
+
+       ao_gps_next.altitude = ao_gps_decimal(0xff);
+       ao_gps_skip_field();    /* skip any fractional portion */
+
+       /* Skip remaining fields */
+       while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
+               ao_gps_lexchar();
+               ao_gps_skip_field();
+       }
+       if (ao_gps_char == '*') {
+               uint8_t cksum = ao_gps_cksum ^ '*';
+               if (cksum != ao_gps_hex(2))
+                       ao_gps_error = 1;
+       } else
+               ao_gps_error = 1;
+       if (!ao_gps_error) {
+               ao_mutex_get(&ao_gps_mutex);
+               ao_gps_tick = ao_gps_next_tick;
+               memcpy(&ao_gps_data, &ao_gps_next, sizeof (struct ao_gps_data));
+               ao_mutex_put(&ao_gps_mutex);
+               ao_wakeup(&ao_gps_data);
+       }
+}
+
+static void
+ao_nmea_gsv(void)
+{
+       char    c;
+       uint8_t i;
+       uint8_t done;
+       /* Now read the data into the GPS tracking data record
+        *
+        * $GPGSV,3,1,12,05,54,069,45,12,44,061,44,21,07,184,46,22,78,289,47*72<CR><LF>
+        *
+        * Satellites in view data
+        *
+        *      3               Total number of GSV messages
+        *      1               Sequence number of current GSV message
+        *      12              Total sats in view (0-12)
+        *      05              SVID
+        *      54              Elevation
+        *      069             Azimuth
+        *      45              C/N0 in dB
+        *      ...             other SVIDs
+        *      72              checksum
+        */
+       c = ao_gps_decimal(1);  /* total messages */
+       i = ao_gps_decimal(1);  /* message sequence */
+       if (i == 1) {
+               ao_gps_tracking_next.channels = 0;
+       }
+       done = (uint8_t) c == i;
+       ao_gps_lexchar();
+       ao_gps_skip_field();    /* sats in view */
+       while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
+               i = ao_gps_tracking_next.channels;
+               c = ao_gps_decimal(2);  /* SVID */
+               if (i < AO_MAX_GPS_TRACKING)
+                       ao_gps_tracking_next.sats[i].svid = c;
+               ao_gps_lexchar();
+               ao_gps_skip_field();    /* elevation */
+               ao_gps_lexchar();
+               ao_gps_skip_field();    /* azimuth */
+               c = ao_gps_decimal(2);  /* C/N0 */
+               if (i < AO_MAX_GPS_TRACKING) {
+                       if (!(ao_gps_tracking_next.sats[i].c_n_1 = c))
+                               ao_gps_tracking_next.sats[i].svid = 0;
+                       ao_gps_tracking_next.channels = i + 1;
+               }
+       }
+       if (ao_gps_char == '*') {
+               uint8_t cksum = ao_gps_cksum ^ '*';
+               if (cksum != ao_gps_hex(2))
+                       ao_gps_error = 1;
+       }
+       else
+               ao_gps_error = 1;
+       if (ao_gps_error)
+               ao_gps_tracking_next.channels = 0;
+       else if (done) {
+               ao_mutex_get(&ao_gps_mutex);
+               memcpy(&ao_gps_tracking_data, &ao_gps_tracking_next,
+                      sizeof(ao_gps_tracking_data));
+               ao_mutex_put(&ao_gps_mutex);
+               ao_wakeup(&ao_gps_tracking_data);
+       }
+}
+
+static void
+ao_nmea_rmc(void)
+{
+       char    a, c;
+       uint8_t i;
+       /* Parse the RMC record to read out the current date */
+
+       /* $GPRMC,111636.932,A,2447.0949,N,12100.5223,E,000.0,000.0,030407,,,A*61
+        *
+        * Recommended Minimum Specific GNSS Data
+        *
+        *      111636.932      UTC time 11:16:36.932
+        *      A               Data Valid (V = receiver warning)
+        *      2447.0949       Latitude
+        *      N               North/south indicator
+        *      12100.5223      Longitude
+        *      E               East/west indicator
+        *      000.0           Speed over ground
+        *      000.0           Course over ground
+        *      030407          UTC date (ddmmyy format)
+        *      A               Mode indicator:
+        *                      N = data not valid
+        *                      A = autonomous mode
+        *                      D = differential mode
+        *                      E = estimated (dead reckoning) mode
+        *                      M = manual input mode
+        *                      S = simulator mode
+        *      61              checksum
+        */
+       ao_gps_skip_field();
+       for (i = 0; i < 8; i++) {
+               ao_gps_lexchar();
+               ao_gps_skip_field();
+       }
+       a = ao_gps_decimal(2);
+       c = ao_gps_decimal(2);
+       i = ao_gps_decimal(2);
+       /* Skip remaining fields */
+       while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
+               ao_gps_lexchar();
+               ao_gps_skip_field();
+       }
+       if (ao_gps_char == '*') {
+               uint8_t cksum = ao_gps_cksum ^ '*';
+               if (cksum != ao_gps_hex(2))
+                       ao_gps_error = 1;
+       } else
+               ao_gps_error = 1;
+       if (!ao_gps_error) {
+               ao_gps_next.year = i;
+               ao_gps_next.month = c;
+               ao_gps_next.day = a;
+               ao_gps_date_flags = AO_GPS_DATE_VALID;
+       }
+}
 
 void
 ao_gps(void) __reentrant
@@ -222,197 +431,11 @@ ao_gps(void) __reentrant
                        continue;
 
                if (a == (uint8_t) 'G' && c == (uint8_t) 'G' && i == (uint8_t) 'A') {
-                       /* Now read the data into the gps data record
-                        *
-                        * $GPGGA,025149.000,4528.1723,N,12244.2480,W,1,05,2.0,103.5,M,-19.5,M,,0000*66
-                        *
-                        * Essential fix data
-                        *
-                        *         025149.000   time (02:51:49.000 GMT)
-                        *         4528.1723,N  Latitude 45°28.1723' N
-                        *         12244.2480,W Longitude 122°44.2480' W
-                        *         1            Fix quality:
-                        *                                 0 = invalid
-                        *                                 1 = GPS fix (SPS)
-                        *                                 2 = DGPS fix
-                        *                                 3 = PPS fix
-                        *                                 4 = Real Time Kinematic
-                        *                                 5 = Float RTK
-                        *                                 6 = estimated (dead reckoning)
-                        *                                 7 = Manual input mode
-                        *                                 8 = Simulation mode
-                        *         05           Number of satellites (5)
-                        *         2.0          Horizontal dilution
-                        *         103.5,M              Altitude, 103.5M above msl
-                        *         -19.5,M              Height of geoid above WGS84 ellipsoid
-                        *         ?            time in seconds since last DGPS update
-                        *         0000         DGPS station ID
-                        *         *66          checksum
-                        */
-
-                       ao_gps_next_tick = ao_time();
-                       ao_gps_next.flags = AO_GPS_RUNNING | ao_gps_date_flags;
-                       ao_gps_next.hour = ao_gps_decimal(2);
-                       ao_gps_next.minute = ao_gps_decimal(2);
-                       ao_gps_next.second = ao_gps_decimal(2);
-                       ao_gps_skip_field();    /* skip seconds fraction */
-
-                       ao_gps_next.latitude = ao_gps_parse_pos(2);
-                       if (ao_gps_parse_flag('N', 'S'))
-                               ao_gps_next.latitude = -ao_gps_next.latitude;
-                       ao_gps_next.longitude = ao_gps_parse_pos(3);
-                       if (ao_gps_parse_flag('E', 'W'))
-                               ao_gps_next.longitude = -ao_gps_next.longitude;
-
-                       i = ao_gps_decimal(0xff);
-                       if (i == 1)
-                               ao_gps_next.flags |= AO_GPS_VALID;
-
-                       i = ao_gps_decimal(0xff) << AO_GPS_NUM_SAT_SHIFT;
-                       if (i > AO_GPS_NUM_SAT_MASK)
-                               i = AO_GPS_NUM_SAT_MASK;
-                       ao_gps_next.flags |= i;
-
-                       ao_gps_lexchar();
-                       ao_gps_next.hdop = ao_gps_decimal(0xff);
-                       if (ao_gps_next.hdop <= 50) {
-                               ao_gps_next.hdop = (uint8_t) 5 * ao_gps_next.hdop;
-                               if (ao_gps_char == '.')
-                                       ao_gps_next.hdop = (ao_gps_next.hdop +
-                                                           ((uint8_t) ao_gps_decimal(1) >> 1));
-                       } else
-                               ao_gps_next.hdop = 255;
-                       ao_gps_skip_field();
-
-                       ao_gps_next.altitude = ao_gps_decimal(0xff);
-                       ao_gps_skip_field();    /* skip any fractional portion */
-
-                       /* Skip remaining fields */
-                       while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
-                               ao_gps_lexchar();
-                               ao_gps_skip_field();
-                       }
-                       if (ao_gps_char == '*') {
-                               uint8_t cksum = ao_gps_cksum ^ '*';
-                               if (cksum != ao_gps_hex(2))
-                                       ao_gps_error = 1;
-                       } else
-                               ao_gps_error = 1;
-                       if (!ao_gps_error) {
-                               ao_mutex_get(&ao_gps_mutex);
-                               ao_gps_tick = ao_gps_next_tick;
-                               memcpy(&ao_gps_data, &ao_gps_next, sizeof (struct ao_gps_data));
-                               ao_mutex_put(&ao_gps_mutex);
-                               ao_wakeup(&ao_gps_data);
-                       }
+                       ao_nmea_gga();
                } else if (a == (uint8_t) 'G' && c == (uint8_t) 'S' && i == (uint8_t) 'V') {
-                       uint8_t done;
-                       /* Now read the data into the GPS tracking data record
-                        *
-                        * $GPGSV,3,1,12,05,54,069,45,12,44,061,44,21,07,184,46,22,78,289,47*72<CR><LF>
-                        *
-                        * Satellites in view data
-                        *
-                        *      3               Total number of GSV messages
-                        *      1               Sequence number of current GSV message
-                        *      12              Total sats in view (0-12)
-                        *      05              SVID
-                        *      54              Elevation
-                        *      069             Azimuth
-                        *      45              C/N0 in dB
-                        *      ...             other SVIDs
-                        *      72              checksum
-                        */
-                       c = ao_gps_decimal(1);  /* total messages */
-                       i = ao_gps_decimal(1);  /* message sequence */
-                       if (i == 1) {
-                               ao_gps_tracking_next.channels = 0;
-                       }
-                       done = (uint8_t) c == i;
-                       ao_gps_lexchar();
-                       ao_gps_skip_field();    /* sats in view */
-                       while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
-                               i = ao_gps_tracking_next.channels;
-                               c = ao_gps_decimal(2);  /* SVID */
-                               if (i < AO_MAX_GPS_TRACKING)
-                                       ao_gps_tracking_next.sats[i].svid = c;
-                               ao_gps_lexchar();
-                               ao_gps_skip_field();    /* elevation */
-                               ao_gps_lexchar();
-                               ao_gps_skip_field();    /* azimuth */
-                               c = ao_gps_decimal(2);  /* C/N0 */
-                               if (i < AO_MAX_GPS_TRACKING) {
-                                       if (!(ao_gps_tracking_next.sats[i].c_n_1 = c))
-                                               ao_gps_tracking_next.sats[i].svid = 0;
-                                       ao_gps_tracking_next.channels = i + 1;
-                               }
-                       }
-                       if (ao_gps_char == '*') {
-                               uint8_t cksum = ao_gps_cksum ^ '*';
-                               if (cksum != ao_gps_hex(2))
-                                       ao_gps_error = 1;
-                       }
-                       else
-                               ao_gps_error = 1;
-                       if (ao_gps_error)
-                               ao_gps_tracking_next.channels = 0;
-                       else if (done) {
-                               ao_mutex_get(&ao_gps_mutex);
-                               memcpy(&ao_gps_tracking_data, &ao_gps_tracking_next,
-                                      sizeof(ao_gps_tracking_data));
-                               ao_mutex_put(&ao_gps_mutex);
-                               ao_wakeup(&ao_gps_tracking_data);
-                       }
+                       ao_nmea_gsv();
                } else if (a == (uint8_t) 'R' && c == (uint8_t) 'M' && i == (uint8_t) 'C') {
-                       /* Parse the RMC record to read out the current date */
-
-                       /* $GPRMC,111636.932,A,2447.0949,N,12100.5223,E,000.0,000.0,030407,,,A*61
-                        *
-                        * Recommended Minimum Specific GNSS Data
-                        *
-                        *      111636.932      UTC time 11:16:36.932
-                        *      A               Data Valid (V = receiver warning)
-                        *      2447.0949       Latitude
-                        *      N               North/south indicator
-                        *      12100.5223      Longitude
-                        *      E               East/west indicator
-                        *      000.0           Speed over ground
-                        *      000.0           Course over ground
-                        *      030407          UTC date (ddmmyy format)
-                        *      A               Mode indicator:
-                        *                      N = data not valid
-                        *                      A = autonomous mode
-                        *                      D = differential mode
-                        *                      E = estimated (dead reckoning) mode
-                        *                      M = manual input mode
-                        *                      S = simulator mode
-                        *      61              checksum
-                        */
-                       ao_gps_skip_field();
-                       for (i = 0; i < 8; i++) {
-                               ao_gps_lexchar();
-                               ao_gps_skip_field();
-                       }
-                       a = ao_gps_decimal(2);
-                       c = ao_gps_decimal(2);
-                       i = ao_gps_decimal(2);
-                       /* Skip remaining fields */
-                       while (ao_gps_char != '*' && ao_gps_char != '\n' && ao_gps_char != '\r') {
-                               ao_gps_lexchar();
-                               ao_gps_skip_field();
-                       }
-                       if (ao_gps_char == '*') {
-                               uint8_t cksum = ao_gps_cksum ^ '*';
-                               if (cksum != ao_gps_hex(2))
-                                       ao_gps_error = 1;
-                       } else
-                               ao_gps_error = 1;
-                       if (!ao_gps_error) {
-                               ao_gps_next.year = i;
-                               ao_gps_next.month = c;
-                               ao_gps_next.day = a;
-                               ao_gps_date_flags = AO_GPS_DATE_VALID;
-                       }
+                       ao_nmea_rmc();
                }
        }
 }