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Diffstat (limited to 'src/ao_gps_skytraq.c')
| -rw-r--r-- | src/ao_gps_skytraq.c | 375 |
1 files changed, 375 insertions, 0 deletions
diff --git a/src/ao_gps_skytraq.c b/src/ao_gps_skytraq.c new file mode 100644 index 00000000..cd5f78b9 --- /dev/null +++ b/src/ao_gps_skytraq.c @@ -0,0 +1,375 @@ +/* + * Copyright © 2009 Keith Packard <keithp@keithp.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ + +#ifndef AO_GPS_TEST +#include "ao.h" +#endif + +#define AO_GPS_LEADER 3 + +static const char ao_gps_header[] = "GPG"; + +__xdata uint8_t ao_gps_mutex; +static __xdata char ao_gps_char; +static __xdata uint8_t ao_gps_cksum; +static __xdata uint8_t ao_gps_error; + +__xdata struct ao_gps_data ao_gps_data; +__xdata struct ao_gps_tracking_data ao_gps_tracking_data; + +static __xdata struct ao_gps_data ao_gps_next; +static __xdata struct ao_gps_tracking_data ao_gps_tracking_next; + +static const char ao_gps_config[] = { + 0xa0, 0xa1, 0x00, 0x09, /* length 9 bytes */ + 0x08, /* configure nmea */ + 1, /* gga interval */ + 1, /* gsa interval */ + 1, /* gsv interval */ + 1, /* gll interval */ + 1, /* rmc interval */ + 1, /* vtg interval */ + 1, /* zda interval */ + 0, /* attributes (0 = update to sram, 1 = update flash too) */ + 0x09, 0x0d, 0x0a, + + 0xa0, 0xa1, 0x00, 0x03, /* length: 3 bytes */ + 0x3c, /* configure navigation mode */ + 0x00, /* 0 = car, 1 = pedestrian */ + 0x00, /* 0 = update to sram, 1 = update sram + flash */ + 0x3c, 0x0d, 0x0a, +}; + +static void +ao_gps_lexchar(void) +{ + if (ao_gps_error) + ao_gps_char = '\n'; + else + ao_gps_char = ao_serial_getchar(); + ao_gps_cksum ^= ao_gps_char; +} + +void +ao_gps_skip(void) +{ + while (ao_gps_char >= '0') + ao_gps_lexchar(); +} + +void +ao_gps_skip_field(void) +{ + while (ao_gps_char != ',' && ao_gps_char != '*' && ao_gps_char != '\n') + ao_gps_lexchar(); +} + +void +ao_gps_skip_sep(void) +{ + if (ao_gps_char == ',' || ao_gps_char == '.' || ao_gps_char == '*') + ao_gps_lexchar(); +} + +__xdata static uint8_t ao_gps_num_width; + +static int16_t +ao_gps_decimal(uint8_t max_width) +{ + int16_t v; + __xdata uint8_t neg = 0; + + ao_gps_skip_sep(); + if (ao_gps_char == '-') { + neg = 1; + ao_gps_lexchar(); + } + v = 0; + ao_gps_num_width = 0; + while (ao_gps_num_width < max_width) { + if (ao_gps_char < '0' || '9' < ao_gps_char) + break; + v = v * (int16_t) 10 + ao_gps_char - '0'; + ao_gps_num_width++; + ao_gps_lexchar(); + } + if (neg) + v = -v; + return v; +} + +static uint8_t +ao_gps_hex(uint8_t max_width) +{ + uint8_t v, d; + + ao_gps_skip_sep(); + v = 0; + ao_gps_num_width = 0; + while (ao_gps_num_width < max_width) { + if ('0' <= ao_gps_char && ao_gps_char <= '9') + d = ao_gps_char - '0'; + else if ('A' <= ao_gps_char && ao_gps_char <= 'F') + d = ao_gps_char - 'A' + 10; + else if ('a' <= ao_gps_char && ao_gps_char <= 'f') + d = ao_gps_char - 'a' + 10; + else + break; + v = (v << 4) | d; + ao_gps_num_width++; + ao_gps_lexchar(); + } + return v; +} + +static int32_t +ao_gps_parse_pos(uint8_t deg_width) __reentrant +{ + int32_t d; + int32_t m; + int32_t f; + + d = ao_gps_decimal(deg_width); + m = ao_gps_decimal(2); + if (ao_gps_char == '.') { + f = ao_gps_decimal(4); + while (ao_gps_num_width < 4) { + f *= 10; + ao_gps_num_width++; + } + } else { + f = 0; + if (ao_gps_char != ',') + ao_gps_error = 1; + } + d = d * 10000000l; + m = m * 10000l + f; + d = d + m * 50 / 3; + return d; +} + +static uint8_t +ao_gps_parse_flag(char no_c, char yes_c) __reentrant +{ + uint8_t ret = 0; + ao_gps_skip_sep(); + if (ao_gps_char == yes_c) + ret = 1; + else if (ao_gps_char == no_c) + ret = 0; + else + ao_gps_error = 1; + ao_gps_lexchar(); + return ret; +} + + +void +ao_gps(void) __reentrant +{ + char c; + uint8_t i; + + ao_serial_set_speed(AO_SERIAL_SPEED_9600); + for (i = 0; i < sizeof (ao_gps_config); i++) + ao_serial_putchar(ao_gps_config[i]); + for (;;) { + /* Locate the begining of the next record */ + for (;;) { + c = ao_serial_getchar(); + if (c == '$') + break; + } + + ao_gps_cksum = 0; + ao_gps_error = 0; + + /* Skip anything other than GPG */ + for (i = 0; i < AO_GPS_LEADER; i++) { + ao_gps_lexchar(); + if (ao_gps_char != ao_gps_header[i]) + break; + } + if (i != AO_GPS_LEADER) + continue; + + /* pull the record identifier characters off the link */ + ao_gps_lexchar(); + c = ao_gps_char; + ao_gps_lexchar(); + i = ao_gps_char; + ao_gps_lexchar(); + if (ao_gps_char != ',') + continue; + + if (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.flags = AO_GPS_RUNNING; + 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_skip_field(); /* Horizontal dilution */ + + 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); + memcpy(&ao_gps_data, &ao_gps_next, sizeof (struct ao_gps_data)); + ao_mutex_put(&ao_gps_mutex); + ao_wakeup(&ao_gps_data); + } + } else if (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; + ao_gps_tracking_next.sats[i].svid = ao_gps_decimal(2); /* SVID */ + ao_gps_lexchar(); + ao_gps_skip_field(); /* elevation */ + ao_gps_lexchar(); + ao_gps_skip_field(); /* azimuth */ + if (ao_gps_tracking_next.sats[i].c_n_1 = ao_gps_decimal(2)) /* C/N0 */ + ao_gps_tracking_next.sats[i].state = 0xbf; + else + ao_gps_tracking_next.sats[i].state = 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); + } + } + } +} + +__xdata struct ao_task ao_gps_task; + +static void +gps_dump(void) __reentrant +{ + ao_mutex_get(&ao_gps_mutex); + ao_gps_print(&ao_gps_data); + putchar('\n'); + ao_gps_tracking_print(&ao_gps_tracking_data); + putchar('\n'); + ao_mutex_put(&ao_gps_mutex); +} + +__code struct ao_cmds ao_gps_cmds[] = { + { 'g', gps_dump, "g Display current GPS values" }, + { 0, gps_dump, NULL }, +}; + +void +ao_gps_init(void) +{ + ao_add_task(&ao_gps_task, ao_gps, "gps"); + ao_cmd_register(&ao_gps_cmds[0]); +} |