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<!DOCTYPE <h <t <link </head><body> <!-- <div <h 00002 00003 00004 00005 00006 00007 00008 00009 00010 00011 00012 00013 00014 00015 00016 00017 00018 00019 00020 00021 00022 00023 00024 00025 00026 00027 00028 00029 00030 00031 00032 00033 00034 00035 00036 00037 00038 00039 00040 00041 00042 00043 00044 00045 { 00046 } 00047 00048 00049 { 00050 00051 } 00052 00053 00054 { 00055 00056 00057 00058 u16 i,j; 00059 00060 00061 00062 00063 { 00064 00065 00066 { 00067 00068 00069 00070 00071 00072 00073 00074 00075 } 00076 00077 00078 } 00079 00080 00081 00082 { 00083 00084 { 00085 00086 00087 { 00088 00089 00090 00091 00092 00093 { 00094 00095 00096 00097 00098 00099 00100 00101 } 00102 00103 00104 00105 00106 00107 00108 00109 00110 00111 00112 00113 00114 00115 00116 00117 00118 } 00119 } 00120 } 00121 00122 00123 { 00124 00125 00126 { 00127 00128 00129 00130 00131 } 00132 00133 { 00134 00135 00136 00137 00138 } 00139 } 00140 00141 { 00142 00143 00144 00145 } 00146 00147 } 00148 00149 00150 { 00151 u08 i; 00152 00153 00154 00155 00156 00157 00158 00159 00160 00161 00162 i = 6; 00163 00164 00165 00166 00167 00168 00169 00170 00171 00172 00173 00174 00175 00176 00177 00178 00179 00180 00181 00182 00183 00184 00185 00186 00187 00188 00189 00190 00191 00192 00193 00194 00195 00196 00197 00198 00199 00200 00201 00202 00203 00204 00205 00206 00207 00208 00209 00210 00211 00212 00213 00214 00215 00216 00217 00218 } 00219 00220 00221 { 00222 u08 i; 00223 00224 00225 00226 00227 00228 00229 00230 00231 00232 i = 6; 00233 00234 00235 00236 00237 00238 00239 00240 00241 00242 00243 00244 00245 00246 00247 00248 00249 00250 00251 00252 00253 00254 00255 00256 00257 00258 } 00259 </ <a <img </body> </html>

HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> tml><head><meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"> itle>Procyon AVRlib: nmea.c Source File</title> href="dox.css" rel="stylesheet" type="text/css"> Generated by Doxygen 1.4.2 --> class="qindex"><a class="qindex" href="main.html">Main Page</a> | <a class="qindex" href="modules.html">Modules</a> | <a class="qindex" href="annotated.html">Data Structures</a> | <a class="qindex" href="dirs.html">Directories</a> | <a class="qindex" href="files.html">File List</a> | <a class="qindex" href="functions.html">Data Fields</a> | <a class="qindex" href="globals.html">Globals</a> | <a class="qindex" href="pages.html">Related Pages</a></div> 1>nmea.c</h1><a href="nmea_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment">00001 /*! \file nmea.c \brief NMEA protocol function library. */ //***************************************************************************** // // File Name : 'nmea.c' // Title : NMEA protocol function library // Author : Pascal Stang - Copyright (C) 2002 // Created : 2002.08.27 // Revised : 2002.08.27 // Version : 0.1 // Target MCU : Atmel AVR Series // Editor Tabs : 4 // // NOTE: This code is currently below version 1.0, and therefore is considered // to be lacking in some functionality or documentation, or may not be fully // tested. Nonetheless, you can expect most functions to work. // // This code is distributed under the GNU Public License // which can be found at http://www.gnu.org/licenses/gpl.txt // //***************************************************************************** #ifndef WIN32 #include <avr/io.h> #include <avr/interrupt.h> #include <avr/pgmspace.h> #endif #include <string.h> #include <stdlib.h> #include <math.h> #include "<a class="code" href="global_8h.html">global.h</a>" #include "<a class="code" href="buffer_8h.html">buffer.h</a>" #include "<a class="code" href="rprintf_8h.html">rprintf.h</a>" #include "<a class="code" href="gps_8h.html">gps.h</a>" #include "<a class="code" href="nmea_8h.html">nmea.h</a>" // Program ROM constants // Global variables extern GpsInfoType GpsInfo; u08 NmeaPacket[NMEA_BUFFERSIZE]; void nmeaInit(void) u08* nmeaGetPacketBuffer(void) return NmeaPacket; u08 nmeaProcess(<a class="code" href="structstruct__cBuffer.html">cBuffer</a>* rxBuffer) u08 foundpacket = NMEA_NODATA; u08 startFlag = FALSE; //u08 data; // process the receive buffer // go through buffer looking for packets while(rxBuffer-><a class="code" href="structstruct__cBuffer.html#o2">datalength</a>) // look for a start of NMEA packet if(<a class="code" href="group__buffer.html#ga4">bufferGetAtIndex</a>(rxBuffer,0) == '$') // found start startFlag = TRUE; // when start is found, we leave it intact in the receive buffer // in case the full NMEA string is not completely received. The // start will be detected in the next nmeaProcess iteration. // done looking for start break; else <a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(rxBuffer); // if we detected a start, look for end of packet if(startFlag) for(i=1; i<(rxBuffer-><a class="code" href="structstruct__cBuffer.html#o2">datalength</a>)-1; i++) // check for end of NMEA packet <CR><LF> if((<a class="code" href="group__buffer.html#ga4">bufferGetAtIndex</a>(rxBuffer,i) == '\r') && (<a class="code" href="group__buffer.html#ga4">bufferGetAtIndex</a>(rxBuffer,i+1) == '\n')) // have a packet end // dump initial '$' <a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(rxBuffer); // copy packet to NmeaPacket for(j=0; j<(i-1); j++) // although NMEA strings should be 80 characters or less, // receive buffer errors can generate erroneous packets. // Protect against packet buffer overflow if(j<(NMEA_BUFFERSIZE-1)) NmeaPacket[j] = <a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(rxBuffer); else <a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(rxBuffer); // null terminate it NmeaPacket[j] = 0; // dump <CR><LF> from rxBuffer <a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(rxBuffer); <a class="code" href="group__buffer.html#ga2">bufferGetFromFront</a>(rxBuffer); #ifdef NMEA_DEBUG_PKT rprintf("Rx NMEA packet type: "); <a class="code" href="group__rprintf.html#ga3">rprintfStrLen</a>(NmeaPacket, 0, 5); <a class="code" href="group__rprintf.html#ga3">rprintfStrLen</a>(NmeaPacket, 5, (i-1)-5); <a class="code" href="group__rprintf.html#ga5">rprintfCRLF</a>(); #endif // found a packet // done with this processing session foundpacket = NMEA_UNKNOWN; break; if(foundpacket) // check message type and process appropriately if(!strncmp(NmeaPacket, "GPGGA", 5)) // process packet of this type nmeaProcessGPGGA(NmeaPacket); // report packet type foundpacket = NMEA_GPGGA; else if(!strncmp(NmeaPacket, "GPVTG", 5)) // process packet of this type nmeaProcessGPVTG(NmeaPacket); // report packet type foundpacket = NMEA_GPVTG; else if(rxBuffer-><a class="code" href="structstruct__cBuffer.html#o2">datalength</a> >= rxBuffer-><a class="code" href="structstruct__cBuffer.html#o1">size</a>) // if we found no packet, and the buffer is full // we're logjammed, flush entire buffer <a class="code" href="group__buffer.html#ga7">bufferFlush</a>(rxBuffer); return foundpacket; void nmeaProcessGPGGA(u08* packet) char* endptr; double degrees, minutesfrac; #ifdef NMEA_DEBUG_GGA rprintf("NMEA: "); <a class="code" href="group__rprintf.html#ga2">rprintfStr</a>(packet); <a class="code" href="group__rprintf.html#ga5">rprintfCRLF</a>(); #endif // start parsing just after "GPGGA," // attempt to reject empty packets right away if(packet[i]==',' && packet[i+1]==',') return; // get UTC time [hhmmss.sss] GpsInfo.PosLLA.TimeOfFix.f = strtod(&packet[i], &endptr); while(packet[i++] != ','); // next field: latitude // get latitude [ddmm.mmmmm] GpsInfo.PosLLA.lat.f = strtod(&packet[i], &endptr); // convert to pure degrees [dd.dddd] format minutesfrac = modf(GpsInfo.PosLLA.lat.f/100, &degrees); GpsInfo.PosLLA.lat.f = degrees + (minutesfrac*100)/60; // convert to radians GpsInfo.PosLLA.lat.f *= (M_PI/180); while(packet[i++] != ','); // next field: N/S indicator // correct latitute for N/S if(packet[i] == 'S') GpsInfo.PosLLA.lat.f = -GpsInfo.PosLLA.lat.f; while(packet[i++] != ','); // next field: longitude // get longitude [ddmm.mmmmm] GpsInfo.PosLLA.lon.f = strtod(&packet[i], &endptr); // convert to pure degrees [dd.dddd] format minutesfrac = modf(GpsInfo.PosLLA.lon.f/100, &degrees); GpsInfo.PosLLA.lon.f = degrees + (minutesfrac*100)/60; // convert to radians GpsInfo.PosLLA.lon.f *= (M_PI/180); while(packet[i++] != ','); // next field: E/W indicator // correct latitute for E/W if(packet[i] == 'W') GpsInfo.PosLLA.lon.f = -GpsInfo.PosLLA.lon.f; while(packet[i++] != ','); // next field: position fix status // position fix status // 0 = Invalid, 1 = Valid SPS, 2 = Valid DGPS, 3 = Valid PPS // check for good position fix if( (packet[i] != '0') && (packet[i] != ',') ) GpsInfo.PosLLA.updates++; while(packet[i++] != ','); // next field: satellites used // get number of satellites used in GPS solution GpsInfo.numSVs = atoi(&packet[i]); while(packet[i++] != ','); // next field: HDOP (horizontal dilution of precision) while(packet[i++] != ','); // next field: altitude // get altitude (in meters) GpsInfo.PosLLA.alt.f = strtod(&packet[i], &endptr); while(packet[i++] != ','); // next field: altitude units, always 'M' while(packet[i++] != ','); // next field: geoid seperation while(packet[i++] != ','); // next field: seperation units while(packet[i++] != ','); // next field: DGPS age while(packet[i++] != ','); // next field: DGPS station ID while(packet[i++] != '*'); // next field: checksum void nmeaProcessGPVTG(u08* packet) char* endptr; #ifdef NMEA_DEBUG_VTG rprintf("NMEA: "); <a class="code" href="group__rprintf.html#ga2">rprintfStr</a>(packet); <a class="code" href="group__rprintf.html#ga5">rprintfCRLF</a>(); #endif // start parsing just after "GPVTG," // attempt to reject empty packets right away if(packet[i]==',' && packet[i+1]==',') return; // get course (true north ref) in degrees [ddd.dd] GpsInfo.VelHS.heading.f = strtod(&packet[i], &endptr); while(packet[i++] != ','); // next field: 'T' while(packet[i++] != ','); // next field: course (magnetic north) // get course (magnetic north ref) in degrees [ddd.dd] //GpsInfo.VelHS.heading.f = strtod(&packet[i], &endptr); while(packet[i++] != ','); // next field: 'M' while(packet[i++] != ','); // next field: speed (knots) // get speed in knots //GpsInfo.VelHS.speed.f = strtod(&packet[i], &endptr); while(packet[i++] != ','); // next field: 'N' while(packet[i++] != ','); // next field: speed (km/h) // get speed in km/h GpsInfo.VelHS.speed.f = strtod(&packet[i], &endptr); while(packet[i++] != ','); // next field: 'K' while(packet[i++] != '*'); // next field: checksum GpsInfo.VelHS.updates++; pre></div><hr size="1"><address style="align: right;">Generated on Sun Oct 29 03:41:07 2006 for Procyon AVRlib by  href="http://www.doxygen.org/index.html"> src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.4.2 </address>

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