?? gps_qemu.c
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#include <errno.h>#include <pthread.h>#include <termios.h>#include <fcntl.h>#include <sys/epoll.h>#include <math.h>#include <time.h>#define LOG_TAG "gps_qemu"#include <cutils/log.h>#include <cutils/sockets.h>#include <cutils/properties.h>#include <hardware/gps.h>/* the name of the qemud-controlled socket */#define QEMUD_SOCKET_NAME "qemud_gps"#define GPS_DEBUG 0#if GPS_DEBUG# define D(...) LOGD(__VA_ARGS__)#else# define D(...) ((void)0)#endif/*****************************************************************//*****************************************************************//***** *****//***** N M E A T O K E N I Z E R *****//***** *****//*****************************************************************//*****************************************************************/typedef struct { const char* p; const char* end;} Token;#define MAX_NMEA_TOKENS 16typedef struct { int count; Token tokens[ MAX_NMEA_TOKENS ];} NmeaTokenizer;static intnmea_tokenizer_init( NmeaTokenizer* t, const char* p, const char* end ){ int count = 0; char* q; // the initial '$' is optional if (p < end && p[0] == '$') p += 1; // remove trailing newline if (end > p && end[-1] == '\n') { end -= 1; if (end > p && end[-1] == '\r') end -= 1; } // get rid of checksum at the end of the sentecne if (end >= p+3 && end[-3] == '*') { end -= 3; } while (p < end) { const char* q = p; q = memchr(p, ',', end-p); if (q == NULL) q = end; if (q > p) { if (count < MAX_NMEA_TOKENS) { t->tokens[count].p = p; t->tokens[count].end = q; count += 1; } } if (q < end) q += 1; p = q; } t->count = count; return count;}static Tokennmea_tokenizer_get( NmeaTokenizer* t, int index ){ Token tok; static const char* dummy = ""; if (index < 0 || index >= t->count) { tok.p = tok.end = dummy; } else tok = t->tokens[index]; return tok;}static intstr2int( const char* p, const char* end ){ int result = 0; int len = end - p; for ( ; len > 0; len--, p++ ) { int c; if (p >= end) goto Fail; c = *p - '0'; if ((unsigned)c >= 10) goto Fail; result = result*10 + c; } return result;Fail: return -1;}static doublestr2float( const char* p, const char* end ){ int result = 0; int len = end - p; char temp[16]; if (len >= (int)sizeof(temp)) return 0.; memcpy( temp, p, len ); temp[len] = 0; return strtod( temp, NULL );}/*****************************************************************//*****************************************************************//***** *****//***** N M E A P A R S E R *****//***** *****//*****************************************************************//*****************************************************************/#define NMEA_MAX_SIZE 83typedef struct { int pos; int overflow; int utc_year; int utc_mon; int utc_day; int utc_diff; GpsLocation fix; gps_location_callback callback; char in[ NMEA_MAX_SIZE+1 ];} NmeaReader;static voidnmea_reader_update_utc_diff( NmeaReader* r ){ time_t now = time(NULL); struct tm tm_local; struct tm tm_utc; long time_local, time_utc; gmtime_r( &now, &tm_utc ); localtime_r( &now, &tm_local ); time_local = tm_local.tm_sec + 60*(tm_local.tm_min + 60*(tm_local.tm_hour + 24*(tm_local.tm_yday + 365*tm_local.tm_year))); time_utc = tm_utc.tm_sec + 60*(tm_utc.tm_min + 60*(tm_utc.tm_hour + 24*(tm_utc.tm_yday + 365*tm_utc.tm_year))); r->utc_diff = time_utc - time_local;}static voidnmea_reader_init( NmeaReader* r ){ memset( r, 0, sizeof(*r) ); r->pos = 0; r->overflow = 0; r->utc_year = -1; r->utc_mon = -1; r->utc_day = -1; r->callback = NULL; nmea_reader_update_utc_diff( r );}static voidnmea_reader_set_callback( NmeaReader* r, gps_location_callback cb ){ r->callback = cb; if (cb != NULL && r->fix.flags != 0) { D("%s: sending latest fix to new callback", __FUNCTION__); r->callback( &r->fix ); r->fix.flags = 0; }}static intnmea_reader_update_time( NmeaReader* r, Token tok ){ int hour, minute; double seconds; struct tm tm; time_t fix_time; if (tok.p + 6 > tok.end) return -1; if (r->utc_year < 0) { // no date yet, get current one time_t now = time(NULL); gmtime_r( &now, &tm ); r->utc_year = tm.tm_year + 1900; r->utc_mon = tm.tm_mon + 1; r->utc_day = tm.tm_mday; } hour = str2int(tok.p, tok.p+2); minute = str2int(tok.p+2, tok.p+4); seconds = str2float(tok.p+4, tok.end); tm.tm_hour = hour; tm.tm_min = minute; tm.tm_sec = (int) seconds; tm.tm_year = r->utc_year - 1900; tm.tm_mon = r->utc_mon - 1; tm.tm_mday = r->utc_day; fix_time = mktime( &tm ) + r->utc_diff; r->fix.timestamp = (long long)fix_time * 1000; return 0;}static intnmea_reader_update_date( NmeaReader* r, Token date, Token time ){ Token tok = date; int day, mon, year; if (tok.p + 6 != tok.end) { D("date not properly formatted: '%.*s'", tok.end-tok.p, tok.p); return -1; } day = str2int(tok.p, tok.p+2); mon = str2int(tok.p+2, tok.p+4); year = str2int(tok.p+4, tok.p+6) + 2000; if ((day|mon|year) < 0) { D("date not properly formatted: '%.*s'", tok.end-tok.p, tok.p); return -1; } r->utc_year = year; r->utc_mon = mon; r->utc_day = day; return nmea_reader_update_time( r, time );}static doubleconvert_from_hhmm( Token tok ){ double val = str2float(tok.p, tok.end); int degrees = (int)(floor(val) / 100); double minutes = val - degrees*100.; double dcoord = degrees + minutes / 60.0; return dcoord;}static intnmea_reader_update_latlong( NmeaReader* r, Token latitude, char latitudeHemi, Token longitude, char longitudeHemi ){ double lat, lon; Token tok; tok = latitude; if (tok.p + 6 > tok.end) { D("latitude is too short: '%.*s'", tok.end-tok.p, tok.p); return -1; } lat = convert_from_hhmm(tok); if (latitudeHemi == 'S') lat = -lat; tok = longitude; if (tok.p + 6 > tok.end) { D("longitude is too short: '%.*s'", tok.end-tok.p, tok.p); return -1; } lon = convert_from_hhmm(tok); if (longitudeHemi == 'W') lon = -lon; r->fix.flags |= GPS_LOCATION_HAS_LAT_LONG; r->fix.latitude = lat; r->fix.longitude = lon; return 0;}static intnmea_reader_update_altitude( NmeaReader* r, Token altitude, Token units ){ double alt; Token tok = altitude; if (tok.p >= tok.end) return -1; r->fix.flags |= GPS_LOCATION_HAS_ALTITUDE; r->fix.altitude = str2float(tok.p, tok.end); return 0;}static intnmea_reader_update_bearing( NmeaReader* r, Token bearing ){ double alt; Token tok = bearing; if (tok.p >= tok.end) return -1; r->fix.flags |= GPS_LOCATION_HAS_BEARING; r->fix.bearing = str2float(tok.p, tok.end); return 0;}static intnmea_reader_update_speed( NmeaReader* r, Token speed ){ double alt; Token tok = speed; if (tok.p >= tok.end) return -1; r->fix.flags |= GPS_LOCATION_HAS_SPEED; r->fix.speed = str2float(tok.p, tok.end); return 0;}static voidnmea_reader_parse( NmeaReader* r ){ /* we received a complete sentence, now parse it to generate * a new GPS fix... */ NmeaTokenizer tzer[1]; Token tok; D("Received: '%.*s'", r->pos, r->in); if (r->pos < 9) { D("Too short. discarded."); return; } nmea_tokenizer_init(tzer, r->in, r->in + r->pos);#if GPS_DEBUG { int n; D("Found %d tokens", tzer->count); for (n = 0; n < tzer->count; n++) { Token tok = nmea_tokenizer_get(tzer,n); D("%2d: '%.*s'", n, tok.end-tok.p, tok.p); } }#endif tok = nmea_tokenizer_get(tzer, 0); if (tok.p + 5 > tok.end) { D("sentence id '%.*s' too short, ignored.", tok.end-tok.p, tok.p); return; } // ignore first two characters. tok.p += 2; if ( !memcmp(tok.p, "GGA", 3) ) { // GPS fix Token tok_time = nmea_tokenizer_get(tzer,1); Token tok_latitude = nmea_tokenizer_get(tzer,2); Token tok_latitudeHemi = nmea_tokenizer_get(tzer,3); Token tok_longitude = nmea_tokenizer_get(tzer,4); Token tok_longitudeHemi = nmea_tokenizer_get(tzer,5); Token tok_altitude = nmea_tokenizer_get(tzer,9); Token tok_altitudeUnits = nmea_tokenizer_get(tzer,10); nmea_reader_update_time(r, tok_time); nmea_reader_update_latlong(r, tok_latitude, tok_latitudeHemi.p[0], tok_longitude, tok_longitudeHemi.p[0]); nmea_reader_update_altitude(r, tok_altitude, tok_altitudeUnits); } else if ( !memcmp(tok.p, "GSA", 3) ) { // do something ? } else if ( !memcmp(tok.p, "RMC", 3) ) { Token tok_time = nmea_tokenizer_get(tzer,1); Token tok_fixStatus = nmea_tokenizer_get(tzer,2); Token tok_latitude = nmea_tokenizer_get(tzer,3); Token tok_latitudeHemi = nmea_tokenizer_get(tzer,4); Token tok_longitude = nmea_tokenizer_get(tzer,5); Token tok_longitudeHemi = nmea_tokenizer_get(tzer,6); Token tok_speed = nmea_tokenizer_get(tzer,7); Token tok_bearing = nmea_tokenizer_get(tzer,8); Token tok_date = nmea_tokenizer_get(tzer,9); D("in RMC, fixStatus=%c", tok_fixStatus.p[0]); if (tok_fixStatus.p[0] == 'A') { nmea_reader_update_date( r, tok_date, tok_time ); nmea_reader_update_latlong( r, tok_latitude, tok_latitudeHemi.p[0], tok_longitude, tok_longitudeHemi.p[0] ); nmea_reader_update_bearing( r, tok_bearing ); nmea_reader_update_speed ( r, tok_speed ); } } else { tok.p -= 2; D("unknown sentence '%.*s", tok.end-tok.p, tok.p); } if (r->fix.flags != 0) {#if GPS_DEBUG char temp[256]; char* p = temp; char* end = p + sizeof(temp); struct tm utc;
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