GPS NEMA String parser library. Only supports SkyTraq Venus chip at this time.
Dependents: MTDOT-EVB-LinkCheck-AL MTDOT-BOX-EVB-Factory-Firmware-LIB-108 TelitSensorToCloud mDot_sensor_to_cloud ... more
GPSPARSER.cpp
- Committer:
- falingtrea
- Date:
- 2015-10-22
- Revision:
- 3:662aa99c5266
- Parent:
- 2:fbc098f1e7c0
- Child:
- 4:ae35903cd8d2
File content as of revision 3:662aa99c5266:
/** * @file NemaParser.cpp * @brief NEMA String to Packet Parser - NEMA strings to compact packet data * @author Tim Barr * @version 1.01 * @see http://www.kh-gps.de/nmea.faq * @see http://www.catb.org/gpsd/NMEA.html * * Copyright (c) 2015 * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * * 09/16/15 TAB V1.01 Changed report rate of GGA and GSA NEMA sentences * 09/22/15 TAB V1.02 Fixed status value for no GPS detected. Increased report rate * of GSV, GGA, and GSA NEMA Sentences * * TODO: Add speed, compass direction, error (DOP) data. Make init more generic */ #include "GPSPARSER.h" using namespace mts; GPSPARSER::GPSPARSER(MTSSerial *uart) : _getSentenceThread(&GPSPARSER::startSentenceThread,this) { _gps_uart = uart; _gps_uart->baud(9600); //set GPS baud rate here _gps_latitude.degrees = 0; _gps_longitude.degrees = 0; _timestamp.tm_sec = 0; _timestamp.tm_min = 0; _timestamp.tm_hour = 0; _timestamp.tm_mday = 0; _timestamp.tm_mon = 0; _timestamp.tm_year = 0; _timestamp.tm_wday = 0; _timestamp.tm_yday = 0; _timestamp.tm_isdst = -1; // time is UTC so no Daylight savings time _gps_status = false; _fix_status = 1; _num_satellites =0; _gps_detected = false; if (GPSPARSER::initGps() == 0){ _gps_detected = true; _getSentenceThread.signal_set(START_THREAD); printf("Started Nema Sentence Thread\r\n"); } else{ printf("No GPS detected\r\n"); _fix_status = 0; } return; } GPSPARSER::~GPSPARSER(void){ if (_gps_detected) _getSentenceThread.terminate(); } uint8_t GPSPARSER::initGps (void){ // this code is specific to the Skytraq Venus GPS chip. This code could be re-written to detect another type of // GPS device. Maybe read serial port for a specific time and detect $GP from NEMA string // Sets Skytraq Venus GPS to output GGA,GSA,GSV every 10 seconds, and RMC every second, no ZDA,GLL,VTG // setup string for GPS GGA GSA GSV GLL RMC VTG ZDA cksum char init_gps[16] = {0xA0,0xA1,0x00,0x09,0x08,0x0A,0x0A,0x0A,0x00,0x01,0x00,0x00,0x00,0x03,0x0D,0x0A}; char chk_char; uint8_t ret = 0; _gps_uart->rxClear(); printf("Starting initGPS \r\n"); _gps_uart->write(init_gps,16); printf("wrote control data\r\n"); do { osDelay(10); } while (!_gps_uart->txEmpty()); osDelay(15); if (_gps_uart->readable()){ do{ _gps_uart->read(chk_char,20); } while ((chk_char != 0xA0) && (!_gps_uart->rxEmpty())); printf ("found 0xA0 or rx empty\r\n"); if (chk_char == 0xA0){ _gps_uart->read(chk_char,15); if (chk_char != 0xA1) { printf( "initGPS failed no message\r\n"); ret = 1; } else { printf("message received\r\n"); _gps_uart->read(chk_char); _gps_uart->read(chk_char); printf("message size - %x\r\n",chk_char); _gps_uart->read(chk_char); if (chk_char != 0x83){ printf("initGPS failed not ack message\r\n"); ret = 1; } else { printf("ACK message received\r\n"); _gps_uart->read(chk_char); printf("config message acknowledged - ID - %x\r\n",chk_char); } } } else { printf("rx empty \r\n"); ret = 1; } } else { printf("No readable characters\r\n"); ret = 1; } printf("initGps done\r\n"); return ret; } void GPSPARSER::startSentenceThread(void const *p){ GPSPARSER *instance = (GPSPARSER*)p; instance->readNemaSentence(); } void GPSPARSER::readNemaSentence (void){ char chk_char; uint8_t calc_cksum; uint8_t nema_cksum; char nema_id[2]; char nema_str[80]; char cksum_str[2]; _getSentenceThread.signal_wait(START_THREAD); printf("Got thread start\r\n"); do { if (_gps_uart->readable() > 80){ do{ _gps_uart->read(chk_char); } while ((chk_char != '$') && (!_gps_uart->rxEmpty())); if (chk_char == '$') { _gps_uart->read(nema_id,2); if (strpbrk(nema_id,"GP") != NULL){ uint8_t i = 0; calc_cksum = 0x17; // 8 bit XOR of G and P checksum seed nema_cksum = 0; // initialize nema string checksum memset(nema_str,0x00,80); // clear nema_str array do { _gps_uart->read(chk_char); if ((chk_char != 0x0D) && (chk_char != '*')){ nema_str[i++] = chk_char; calc_cksum ^= chk_char; // 8 bit XOR checksum } if (chk_char == '*') { _gps_uart->read(cksum_str,2); nema_cksum = (uint8_t)strtoul(cksum_str,NULL,16); } } while (( chk_char != 0x0D) && !_gps_uart->rxEmpty()); if (nema_cksum == calc_cksum) if (strncmp (nema_str,"GGA",3) == 0) parseGGA(nema_str); else if (strncmp (nema_str,"GSA",3) == 0) parseGSA(nema_str); else if (strncmp (nema_str,"GSV",3) == 0) parseGSV(nema_str); else if (strncmp (nema_str,"GLL",3) == 0) parseGLL(nema_str); else if (strncmp (nema_str,"RMC",3) == 0) parseRMC(nema_str); else if (strncmp (nema_str,"VTG",3) == 0) parseVTG(nema_str); else if (strncmp (nema_str,"ZDA",3) == 0) parseZDA(nema_str); else printf("Unknown NEMA String Type\r\n"); else printf("NEMA String checksum error %x != %x\r\n",nema_cksum,calc_cksum); } } else printf("RX empty before all data read\r\n"); } osDelay(100); } while(true); } uint8_t GPSPARSER::parseGGA(char *nema_buf){ char* token_str; uint8_t ret = 0; token_str = strtok(nema_buf, ","); // skip timestamp token_str = strtok(NULL, ","); // skip latitude degrees minutes token_str = strtok(NULL, ","); token_str = strtok(NULL, ","); // skip longitude degree minutes token_str = strtok(NULL, ","); token_str = strtok(NULL, ","); // read fix quality token_str = strtok(NULL, ","); _fix_quality = atoi(token_str); // skip number of satellites and horizontal dilution token_str = strtok(NULL, ","); token_str = strtok(NULL, ","); // read msl altitude in meters token_str = strtok(NULL, ","); _msl_altitude = atoi(token_str); return ret; } uint8_t GPSPARSER::parseGSA(char *nema_buf){ char* token_str; uint8_t ret = 0; token_str = strtok(nema_buf, ","); token_str = strtok(NULL, ","); // read fix status token_str = strtok(NULL, ","); _fix_status = atoi(token_str); // read satellite PRNs for (uint8_t i=0;i<12;i++){ token_str = strtok(NULL, ","); _satellite_prn[i] = atoi(token_str); } return ret; } uint8_t GPSPARSER::parseGSV(char *nema_buf){ char* token_str; uint8_t ret = 0; token_str = strtok(nema_buf, ","); // skip number of sentences and sentence number for now token_str = strtok(NULL, ","); token_str = strtok(NULL, ","); // read Number of satellites token_str = strtok(NULL, ","); _num_satellites = atoi(token_str); // add code to read satellite specs if needed return ret; } uint8_t GPSPARSER::parseRMC(char *nema_buf){ char* token_str; char temp_str[6]; uint8_t ret = 0; token_str = strtok(nema_buf, ","); // read timestamp token_str = strtok(NULL, ","); strncpy(temp_str,token_str,2); _timestamp.tm_hour = atoi(temp_str); memset(temp_str,0x00,6); strncpy(temp_str,token_str+2,2); _timestamp.tm_min = atoi(temp_str); memset(temp_str,0x00,6); strncpy(temp_str,token_str+4,2); _timestamp.tm_sec = atoi(temp_str); // set gps_status true = active token_str = strtok(NULL, ","); memset(temp_str,0x00,6); strncpy(temp_str,token_str,1); if (temp_str[0] == 'A') _gps_status = true; else _gps_status = false; // read latitude degrees minutes token_str = strtok(NULL, "."); memset(temp_str,0x00,6); strncpy(temp_str,token_str,2); _gps_latitude.degrees = atoi(temp_str); memset(temp_str,0x00,6); strncpy(temp_str,token_str+2,2); _gps_latitude.minutes = atoi(temp_str); // read fractional minutes token_str = strtok(NULL, ","); _gps_latitude.seconds = atoi(token_str); // read latitude hemisphere change sign if 'S' token_str = strtok(NULL, ","); if (token_str[0] == 'S') _gps_latitude.degrees *= -1; // read longitude degree minutes token_str = strtok(NULL, "."); memset(temp_str,0x00,6); strncpy(temp_str,token_str,3); _gps_longitude.degrees = atoi(temp_str); memset(temp_str,0x00,6); strncpy(temp_str,token_str+3,2); _gps_longitude.minutes = atoi(temp_str); // read fractional minutes token_str = strtok(NULL, ","); _gps_longitude.seconds = atoi(token_str); // read longitude hemisphere change sign if 'W' token_str = strtok(NULL, ","); if (token_str[0] == 'W') _gps_longitude.degrees *= -1; // skip speed and track angle token_str = strtok(NULL, ","); token_str = strtok(NULL, ","); // read date token_str = strtok(NULL, ","); memset(temp_str,0x00,6); strncpy(temp_str,token_str,2); _timestamp.tm_mday = atoi(temp_str); memset(temp_str,0x00,6); strncpy(temp_str,token_str+2,2); _timestamp.tm_mon = atoi(temp_str) - 1; memset(temp_str,0x00,6); strncpy(temp_str,token_str+4,2); _timestamp.tm_year = atoi(temp_str) + 100; return ret; } uint8_t GPSPARSER::parseVTG(char *nema_buf){ uint8_t ret = 0; printf("ParseVTG****\r\n"); printf(nema_buf); printf("\r\n"); return ret; } uint8_t GPSPARSER::parseGLL(char *nema_buf){ uint8_t ret = 0; printf("ParseGLL*****\r\n"); printf(nema_buf); printf("\r\n"); return ret; } uint8_t GPSPARSER::parseZDA(char *nema_buf){ uint8_t ret = 0; printf("ParseZDA******\r\n"); printf(nema_buf); printf("\r\n"); return ret; } bool GPSPARSER::gpsDetected(void){ return _gps_detected; } GPSPARSER::longitude GPSPARSER::getLongitude(void){ return _gps_longitude; } GPSPARSER::latitude GPSPARSER::getLatitude(void){ return _gps_latitude; } struct tm GPSPARSER::getTimestamp(void){ return _timestamp; } bool GPSPARSER::getLockStatus(void){ return _gps_status; } uint8_t GPSPARSER::getFixStatus(void){ return _fix_status; } uint8_t GPSPARSER::getFixQuality(void){ return _fix_quality; } uint8_t GPSPARSER::getNumSatellites(void){ return _num_satellites; } int16_t GPSPARSER::getAltitude(void){ return _msl_altitude; }