diff options
author | Lorenz Meier <lm@inf.ethz.ch> | 2014-11-26 07:56:54 +0100 |
---|---|---|
committer | Lorenz Meier <lm@inf.ethz.ch> | 2014-11-26 07:56:54 +0100 |
commit | 6200a3e3a5f24f40ff9da8b3fb366b7014656941 (patch) | |
tree | 5fc03991b903894d869125af757954de92331279 /src/drivers/gps/ashtech.cpp | |
parent | 034d0a6a610c8838d6c43b51a4401ce818b77624 (diff) | |
parent | cbcd1ea1d143dfddd2331fb14d17d7be48fa8b6f (diff) | |
download | px4-firmware-6200a3e3a5f24f40ff9da8b3fb366b7014656941.tar.gz px4-firmware-6200a3e3a5f24f40ff9da8b3fb366b7014656941.tar.bz2 px4-firmware-6200a3e3a5f24f40ff9da8b3fb366b7014656941.zip |
Added TeraRanger one sensor
Diffstat (limited to 'src/drivers/gps/ashtech.cpp')
-rw-r--r-- | src/drivers/gps/ashtech.cpp | 641 |
1 files changed, 641 insertions, 0 deletions
diff --git a/src/drivers/gps/ashtech.cpp b/src/drivers/gps/ashtech.cpp new file mode 100644 index 000000000..a2e292de2 --- /dev/null +++ b/src/drivers/gps/ashtech.cpp @@ -0,0 +1,641 @@ +#include "ashtech.h" + +#include <unistd.h> +#include <stdlib.h> +#include <stdio.h> +#include <poll.h> +#include <math.h> +#include <string.h> +#include <assert.h> +#include <systemlib/err.h> +#include <uORB/uORB.h> +#include <uORB/topics/vehicle_gps_position.h> +#include <uORB/topics/satellite_info.h> +#include <drivers/drv_hrt.h> + +#include <fcntl.h> +#include <math.h> + +ASHTECH::ASHTECH(const int &fd, struct vehicle_gps_position_s *gps_position, struct satellite_info_s *satellite_info): + _fd(fd), + _satellite_info(satellite_info), + _gps_position(gps_position) +{ + decode_init(); + _decode_state = NME_DECODE_UNINIT; + _rx_buffer_bytes = 0; +} + +ASHTECH::~ASHTECH() +{ +} + +/* + * All NMEA descriptions are taken from + * http://www.trimble.com/OEM_ReceiverHelp/V4.44/en/NMEA-0183messages_MessageOverview.html + */ + +int ASHTECH::handle_message(int len) +{ + char * endp; + + if (len < 7) { return 0; } + + int uiCalcComma = 0; + + for (int i = 0 ; i < len; i++) { + if (_rx_buffer[i] == ',') { uiCalcComma++; } + } + + char *bufptr = (char *)(_rx_buffer + 6); + + if ((memcmp(_rx_buffer + 3, "ZDA,", 3) == 0) && (uiCalcComma == 6)) { + /* + UTC day, month, and year, and local time zone offset + An example of the ZDA message string is: + + $GPZDA,172809.456,12,07,1996,00,00*45 + + ZDA message fields + Field Meaning + 0 Message ID $GPZDA + 1 UTC + 2 Day, ranging between 01 and 31 + 3 Month, ranging between 01 and 12 + 4 Year + 5 Local time zone offset from GMT, ranging from 00 through 13 hours + 6 Local time zone offset from GMT, ranging from 00 through 59 minutes + 7 The checksum data, always begins with * + Fields 5 and 6 together yield the total offset. For example, if field 5 is -5 and field 6 is +15, local time is 5 hours and 15 minutes earlier than GMT. + */ + double ashtech_time = 0.0; + int day = 0, month = 0, year = 0, local_time_off_hour __attribute__((unused)) = 0, local_time_off_min __attribute__((unused)) = 0; + + if (bufptr && *(++bufptr) != ',') { ashtech_time = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { day = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { month = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { year = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { local_time_off_hour = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { local_time_off_min = strtol(bufptr, &endp, 10); bufptr = endp; } + + + int ashtech_hour = ashtech_time / 10000; + int ashtech_minute = (ashtech_time - ashtech_hour * 10000) / 100; + double ashtech_sec = ashtech_time - ashtech_hour * 10000 - ashtech_minute * 100; + /* + * convert to unix timestamp + */ + struct tm timeinfo; + timeinfo.tm_year = year - 1900; + timeinfo.tm_mon = month - 1; + timeinfo.tm_mday = day; + timeinfo.tm_hour = ashtech_hour; + timeinfo.tm_min = ashtech_minute; + timeinfo.tm_sec = int(ashtech_sec); + time_t epoch = mktime(&timeinfo); + + _gps_position->time_gps_usec = (uint64_t)epoch * 1000000; //TODO: test this + _gps_position->time_gps_usec += (uint64_t)((ashtech_sec - int(ashtech_sec)) * 1e6); + _gps_position->timestamp_time = hrt_absolute_time(); + } + + else if ((memcmp(_rx_buffer + 3, "GGA,", 3) == 0) && (uiCalcComma == 14)) { + /* + Time, position, and fix related data + An example of the GBS message string is: + + $GPGGA,172814.0,3723.46587704,N,12202.26957864,W,2,6,1.2,18.893,M,-25.669,M,2.0,0031*4F + + Note - The data string exceeds the ASHTECH standard length. + GGA message fields + Field Meaning + 0 Message ID $GPGGA + 1 UTC of position fix + 2 Latitude + 3 Direction of latitude: + N: North + S: South + 4 Longitude + 5 Direction of longitude: + E: East + W: West + 6 GPS Quality indicator: + 0: Fix not valid + 1: GPS fix + 2: Differential GPS fix, OmniSTAR VBS + 4: Real-Time Kinematic, fixed integers + 5: Real-Time Kinematic, float integers, OmniSTAR XP/HP or Location RTK + 7 Number of SVs in use, range from 00 through to 24+ + 8 HDOP + 9 Orthometric height (MSL reference) + 10 M: unit of measure for orthometric height is meters + 11 Geoid separation + 12 M: geoid separation measured in meters + 13 Age of differential GPS data record, Type 1 or Type 9. Null field when DGPS is not used. + 14 Reference station ID, range 0000-4095. A null field when any reference station ID is selected and no corrections are received1. + 15 + The checksum data, always begins with * + Note - If a user-defined geoid model, or an inclined + */ + double ashtech_time __attribute__((unused)) = 0.0, lat = 0.0, lon = 0.0, alt = 0.0; + int num_of_sv __attribute__((unused)) = 0, fix_quality = 0; + double hdop __attribute__((unused)) = 99.9; + char ns = '?', ew = '?'; + + if (bufptr && *(++bufptr) != ',') { ashtech_time = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { lat = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { ns = *(bufptr++); } + + if (bufptr && *(++bufptr) != ',') { lon = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { ew = *(bufptr++); } + + if (bufptr && *(++bufptr) != ',') { fix_quality = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { num_of_sv = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { hdop = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { alt = strtod(bufptr, &endp); bufptr = endp; } + + if (ns == 'S') { + lat = -lat; + } + + if (ew == 'W') { + lon = -lon; + } + + _gps_position->lat = (int(lat * 0.01) + (lat * 0.01 - int(lat * 0.01)) * 100.0 / 60.0) * 10000000; + _gps_position->lon = (int(lon * 0.01) + (lon * 0.01 - int(lon * 0.01)) * 100.0 / 60.0) * 10000000; + _gps_position->alt = alt * 1000; + _rate_count_lat_lon++; + + if (fix_quality <= 0) { + _gps_position->fix_type = 0; + + } else { + /* + * in this NMEA message float integers (value 5) mode has higher value than fixed integers (value 4), whereas it provides lower quality, + * and since value 3 is not being used, I "moved" value 5 to 3 to add it to _gps_position->fix_type + */ + if (fix_quality == 5) { fix_quality = 3; } + + /* + * fix quality 1 means just a normal 3D fix, so I'm subtracting 1 here. This way we'll have 3 for auto, 4 for DGPS, 5 for floats, 6 for fixed. + */ + _gps_position->fix_type = 3 + fix_quality - 1; + } + + _gps_position->timestamp_position = hrt_absolute_time(); + + _gps_position->vel_m_s = 0; /**< GPS ground speed (m/s) */ + _gps_position->vel_n_m_s = 0; /**< GPS ground speed in m/s */ + _gps_position->vel_e_m_s = 0; /**< GPS ground speed in m/s */ + _gps_position->vel_d_m_s = 0; /**< GPS ground speed in m/s */ + _gps_position->cog_rad = + 0; /**< Course over ground (NOT heading, but direction of movement) in rad, -PI..PI */ + _gps_position->vel_ned_valid = true; /**< Flag to indicate if NED speed is valid */ + _gps_position->c_variance_rad = 0.1; + _gps_position->timestamp_velocity = hrt_absolute_time(); + return 1; + + } else if ((memcmp(_rx_buffer, "$PASHR,POS,", 11) == 0) && (uiCalcComma == 18)) { + /* + Example $PASHR,POS,2,10,125410.00,5525.8138702,N,03833.9587380,E,131.555,1.0,0.0,0.007,-0.001,2.0,1.0,1.7,1.0,*34 + + $PASHR,POS,d1,d2,m3,m4,c5,m6,c7,f8,f9,f10,f11,f12,f13,f14,f15,f16,s17*cc + Parameter Description Range + d1 Position mode 0: standalone + 1: differential + 2: RTK float + 3: RTK fixed + 5: Dead reckoning + 9: SBAS (see NPT setting) + d2 Number of satellite used in position fix 0-99 + m3 Current UTC time of position fix (hhmmss.ss) 000000.00-235959.99 + m4 Latitude of position (ddmm.mmmmmm) 0-90 degrees 00-59.9999999 minutes + c5 Latitude sector N, S + m6 Longitude of position (dddmm.mmmmmm) 0-180 degrees 00-59.9999999 minutes + c7 Longitude sector E,W + f8 Altitude above ellipsoid +9999.000 + f9 Differential age (data link age), seconds 0.0-600.0 + f10 True track/course over ground in degrees 0.0-359.9 + f11 Speed over ground in knots 0.0-999.9 + f12 Vertical velocity in decimeters per second +999.9 + f13 PDOP 0-99.9 + f14 HDOP 0-99.9 + f15 VDOP 0-99.9 + f16 TDOP 0-99.9 + s17 Reserved no data + *cc Checksum + */ + bufptr = (char *)(_rx_buffer + 10); + + /* + * Ashtech would return empty space as coordinate (lat, lon or alt) if it doesn't have a fix yet + */ + int coordinatesFound = 0; + double ashtech_time __attribute__((unused)) = 0.0, lat = 0.0, lon = 0.0, alt = 0.0; + int num_of_sv __attribute__((unused)) = 0, fix_quality = 0; + double track_true = 0.0, ground_speed = 0.0 , age_of_corr __attribute__((unused)) = 0.0; + double hdop __attribute__((unused)) = 99.9, vdop __attribute__((unused)) = 99.9, pdop __attribute__((unused)) = 99.9, tdop __attribute__((unused)) = 99.9, vertic_vel = 0.0; + char ns = '?', ew = '?'; + + if (bufptr && *(++bufptr) != ',') { fix_quality = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { num_of_sv = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { ashtech_time = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { + /* + * if a coordinate is skipped (i.e. no fix), it either won't get into this block (two commas in a row) + * or strtod won't find anything and endp will point exactly where bufptr is. The same is for lon and alt. + */ + lat = strtod(bufptr, &endp); + if (bufptr != endp) {coordinatesFound++;} + bufptr = endp; + } + + if (bufptr && *(++bufptr) != ',') { ns = *(bufptr++); } + + if (bufptr && *(++bufptr) != ',') { + lon = strtod(bufptr, &endp); + if (bufptr != endp) {coordinatesFound++;} + bufptr = endp; + } + + if (bufptr && *(++bufptr) != ',') { ew = *(bufptr++); } + + if (bufptr && *(++bufptr) != ',') { + alt = strtod(bufptr, &endp); + if (bufptr != endp) {coordinatesFound++;} + bufptr = endp; + } + + if (bufptr && *(++bufptr) != ',') { age_of_corr = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { track_true = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { ground_speed = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { vertic_vel = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { pdop = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { hdop = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { vdop = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { tdop = strtod(bufptr, &endp); bufptr = endp; } + + if (ns == 'S') { + lat = -lat; + } + + if (ew == 'W') { + lon = -lon; + } + + _gps_position->lat = (int(lat * 0.01) + (lat * 0.01 - int(lat * 0.01)) * 100.0 / 60.0) * 10000000; + _gps_position->lon = (int(lon * 0.01) + (lon * 0.01 - int(lon * 0.01)) * 100.0 / 60.0) * 10000000; + _gps_position->alt = alt * 1000; + _rate_count_lat_lon++; + + if (coordinatesFound < 3) { + _gps_position->fix_type = 0; + + } else { + _gps_position->fix_type = 3 + fix_quality; + } + + _gps_position->timestamp_position = hrt_absolute_time(); + + double track_rad = track_true * M_PI / 180.0; + + double velocity_ms = ground_speed / 1.9438445; /** knots to m/s */ + double velocity_north = velocity_ms * cos(track_rad); + double velocity_east = velocity_ms * sin(track_rad); + + _gps_position->vel_m_s = velocity_ms; /**< GPS ground speed (m/s) */ + _gps_position->vel_n_m_s = velocity_north; /**< GPS ground speed in m/s */ + _gps_position->vel_e_m_s = velocity_east; /**< GPS ground speed in m/s */ + _gps_position->vel_d_m_s = -vertic_vel; /**< GPS ground speed in m/s */ + _gps_position->cog_rad = + track_rad; /**< Course over ground (NOT heading, but direction of movement) in rad, -PI..PI */ + _gps_position->vel_ned_valid = true; /**< Flag to indicate if NED speed is valid */ + _gps_position->c_variance_rad = 0.1; + _gps_position->timestamp_velocity = hrt_absolute_time(); + return 1; + + } else if ((memcmp(_rx_buffer + 3, "GST,", 3) == 0) && (uiCalcComma == 8)) { + /* + Position error statistics + An example of the GST message string is: + + $GPGST,172814.0,0.006,0.023,0.020,273.6,0.023,0.020,0.031*6A + + The Talker ID ($--) will vary depending on the satellite system used for the position solution: + + $GP - GPS only + $GL - GLONASS only + $GN - Combined + GST message fields + Field Meaning + 0 Message ID $GPGST + 1 UTC of position fix + 2 RMS value of the pseudorange residuals; includes carrier phase residuals during periods of RTK (float) and RTK (fixed) processing + 3 Error ellipse semi-major axis 1 sigma error, in meters + 4 Error ellipse semi-minor axis 1 sigma error, in meters + 5 Error ellipse orientation, degrees from true north + 6 Latitude 1 sigma error, in meters + 7 Longitude 1 sigma error, in meters + 8 Height 1 sigma error, in meters + 9 The checksum data, always begins with * + */ + double ashtech_time __attribute__((unused)) = 0.0, lat_err = 0.0, lon_err = 0.0, alt_err = 0.0; + double min_err __attribute__((unused)) = 0.0, maj_err __attribute__((unused)) = 0.0, deg_from_north __attribute__((unused)) = 0.0, rms_err __attribute__((unused)) = 0.0; + + if (bufptr && *(++bufptr) != ',') { ashtech_time = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { rms_err = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { maj_err = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { min_err = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { deg_from_north = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { lat_err = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { lon_err = strtod(bufptr, &endp); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { alt_err = strtod(bufptr, &endp); bufptr = endp; } + + _gps_position->eph = sqrt(lat_err * lat_err + lon_err * lon_err); + _gps_position->epv = alt_err; + + _gps_position->s_variance_m_s = 0; + _gps_position->timestamp_variance = hrt_absolute_time(); + + } else if ((memcmp(_rx_buffer + 3, "GSV,", 3) == 0)) { + /* + The GSV message string identifies the number of SVs in view, the PRN numbers, elevations, azimuths, and SNR values. An example of the GSV message string is: + + $GPGSV,4,1,13,02,02,213,,03,-3,000,,11,00,121,,14,13,172,05*67 + + GSV message fields + Field Meaning + 0 Message ID $GPGSV + 1 Total number of messages of this type in this cycle + 2 Message number + 3 Total number of SVs visible + 4 SV PRN number + 5 Elevation, in degrees, 90 maximum + 6 Azimuth, degrees from True North, 000 through 359 + 7 SNR, 00 through 99 dB (null when not tracking) + 8-11 Information about second SV, same format as fields 4 through 7 + 12-15 Information about third SV, same format as fields 4 through 7 + 16-19 Information about fourth SV, same format as fields 4 through 7 + 20 The checksum data, always begins with * + */ + /* + * currently process only gps, because do not know what + * Global satellite ID I should use for non GPS sats + */ + bool bGPS = false; + + if (memcmp(_rx_buffer, "$GP", 3) != 0) { + return 0; + + } else { + bGPS = true; + } + + int all_msg_num = 0, this_msg_num = 0, tot_sv_visible = 0; + struct gsv_sat { + int svid; + int elevation; + int azimuth; + int snr; + } sat[4]; + memset(sat, 0, sizeof(sat)); + + if (bufptr && *(++bufptr) != ',') { all_msg_num = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { this_msg_num = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { tot_sv_visible = strtol(bufptr, &endp, 10); bufptr = endp; } + + if ((this_msg_num < 1) || (this_msg_num > all_msg_num)) { + return 0; + } + + if ((this_msg_num == 0) && (bGPS == true)) { + memset(_satellite_info->svid, 0, sizeof(_satellite_info->svid)); + memset(_satellite_info->used, 0, sizeof(_satellite_info->used)); + memset(_satellite_info->snr, 0, sizeof(_satellite_info->snr)); + memset(_satellite_info->elevation, 0, sizeof(_satellite_info->elevation)); + memset(_satellite_info->azimuth, 0, sizeof(_satellite_info->azimuth)); + } + + int end = 4; + + if (this_msg_num == all_msg_num) { + end = tot_sv_visible - (this_msg_num - 1) * 4; + _gps_position->satellites_used = tot_sv_visible; + _satellite_info->count = SAT_INFO_MAX_SATELLITES; + _satellite_info->timestamp = hrt_absolute_time(); + } + + for (int y = 0 ; y < end ; y++) { + if (bufptr && *(++bufptr) != ',') { sat[y].svid = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { sat[y].elevation = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { sat[y].azimuth = strtol(bufptr, &endp, 10); bufptr = endp; } + + if (bufptr && *(++bufptr) != ',') { sat[y].snr = strtol(bufptr, &endp, 10); bufptr = endp; } + + _satellite_info->svid[y + (this_msg_num - 1) * 4] = sat[y].svid; + _satellite_info->used[y + (this_msg_num - 1) * 4] = ((sat[y].snr > 0) ? true : false); + _satellite_info->snr[y + (this_msg_num - 1) * 4] = sat[y].snr; + _satellite_info->elevation[y + (this_msg_num - 1) * 4] = sat[y].elevation; + _satellite_info->azimuth[y + (this_msg_num - 1) * 4] = sat[y].azimuth; + } + } + + return 0; +} + + +int ASHTECH::receive(unsigned timeout) +{ + { + /* poll descriptor */ + pollfd fds[1]; + fds[0].fd = _fd; + fds[0].events = POLLIN; + + uint8_t buf[32]; + + /* timeout additional to poll */ + uint64_t time_started = hrt_absolute_time(); + + int j = 0; + ssize_t bytes_count = 0; + + while (true) { + + /* pass received bytes to the packet decoder */ + while (j < bytes_count) { + int l = 0; + + if ((l = parse_char(buf[j])) > 0) { + /* return to configure during configuration or to the gps driver during normal work + * if a packet has arrived */ + if (handle_message(l) > 0) { + return 1; + } + } + + /* in case we keep trying but only get crap from GPS */ + if (time_started + timeout * 1000 * 2 < hrt_absolute_time()) { + return -1; + } + + j++; + } + + /* everything is read */ + j = bytes_count = 0; + + /* then poll for new data */ + int ret = ::poll(fds, sizeof(fds) / sizeof(fds[0]), timeout * 2); + + if (ret < 0) { + /* something went wrong when polling */ + return -1; + + } else if (ret == 0) { + /* Timeout */ + return -1; + + } else if (ret > 0) { + /* if we have new data from GPS, go handle it */ + if (fds[0].revents & POLLIN) { + /* + * We are here because poll says there is some data, so this + * won't block even on a blocking device. If more bytes are + * available, we'll go back to poll() again... + */ + bytes_count = ::read(_fd, buf, sizeof(buf)); + } + } + } + } + +} +#define HEXDIGIT_CHAR(d) ((char)((d) + (((d) < 0xA) ? '0' : 'A'-0xA))) + +int ASHTECH::parse_char(uint8_t b) +{ + int iRet = 0; + + switch (_decode_state) { + /* First, look for sync1 */ + case NME_DECODE_UNINIT: + if (b == '$') { + _decode_state = NME_DECODE_GOT_SYNC1; + _rx_buffer_bytes = 0; + _rx_buffer[_rx_buffer_bytes++] = b; + } + + break; + + case NME_DECODE_GOT_SYNC1: + if (b == '$') { + _decode_state = NME_DECODE_GOT_SYNC1; + _rx_buffer_bytes = 0; + + } else if (b == '*') { + _decode_state = NME_DECODE_GOT_ASTERIKS; + } + + if (_rx_buffer_bytes >= (sizeof(_rx_buffer) - 5)) { + _decode_state = NME_DECODE_UNINIT; + _rx_buffer_bytes = 0; + + } else { + _rx_buffer[_rx_buffer_bytes++] = b; + } + + break; + + case NME_DECODE_GOT_ASTERIKS: + _rx_buffer[_rx_buffer_bytes++] = b; + _decode_state = NME_DECODE_GOT_FIRST_CS_BYTE; + break; + + case NME_DECODE_GOT_FIRST_CS_BYTE: + _rx_buffer[_rx_buffer_bytes++] = b; + uint8_t checksum = 0; + uint8_t *buffer = _rx_buffer + 1; + uint8_t *bufend = _rx_buffer + _rx_buffer_bytes - 3; + + for (; buffer < bufend; buffer++) { checksum ^= *buffer; } + + if ((HEXDIGIT_CHAR(checksum >> 4) == *(_rx_buffer + _rx_buffer_bytes - 2)) && + (HEXDIGIT_CHAR(checksum & 0x0F) == *(_rx_buffer + _rx_buffer_bytes - 1))) { + iRet = _rx_buffer_bytes; + } + + _decode_state = NME_DECODE_UNINIT; + _rx_buffer_bytes = 0; + break; + } + + return iRet; +} + +void ASHTECH::decode_init(void) +{ + +} + +/* + * ashtech board configuration script + */ + +const char comm[] = "$PASHS,POP,20\r\n"\ + "$PASHS,NME,ZDA,B,ON,3\r\n"\ + "$PASHS,NME,GGA,B,OFF\r\n"\ + "$PASHS,NME,GST,B,ON,3\r\n"\ + "$PASHS,NME,POS,B,ON,0.05\r\n"\ + "$PASHS,NME,GSV,B,ON,3\r\n"\ + "$PASHS,SPD,A,8\r\n"\ + "$PASHS,SPD,B,9\r\n"; + +int ASHTECH::configure(unsigned &baudrate) +{ + /* try different baudrates */ + const unsigned baudrates_to_try[] = {9600, 38400, 19200, 57600, 115200}; + + + for (unsigned int baud_i = 0; baud_i < sizeof(baudrates_to_try) / sizeof(baudrates_to_try[0]); baud_i++) { + baudrate = baudrates_to_try[baud_i]; + set_baudrate(_fd, baudrate); + write(_fd, (uint8_t *)comm, sizeof(comm)); + } + + set_baudrate(_fd, 115200); + return 0; +} |