main.cpp

00001 // GPS Logger mbed LPC11U24
00002 
00003 #include "mbed.h"
00004 #include "SDFileSystem.h"
00005 
00006 SDFileSystem sd(p5, p6, p7, p8, "fs");
00007 
00008 Serial gps(p9, p10);
00009 Serial pc(USBTX, USBRX);
00010 
00011 InterruptIn pps(p14);
00012 
00013 DigitalOut pps_stat(LED1);
00014 DigitalOut sd_access(LED2);
00015 DigitalOut rx_status(LED3);
00016 DigitalIn enable(p22);
00017 
00018 int num = 0;
00019 int pps_count = 0;
00020 
00021 // GPS 1pps interrupt
00022 void int_pps() {
00023     pps_stat =! pps_stat;
00024     pps_count += 1;
00025 }
00026 
00027 
00028 int main() {
00029     
00030     char tmp;
00031     char data[80];
00032     int log_count = 0;
00033     bool rec_flag = false;
00034     int before_sw = 1;
00035     FILE *fp = NULL;
00036     
00037     enable.mode(PullUp);
00038 
00039     pps_stat = 0;
00040     sd_access = 0;
00041     rx_status = 0;
00042 
00043     pps.rise(&int_pps); 
00044     gps.baud(115200);
00045     
00046     
00047     sd_access = 1;
00048 
00049     while (1) {
00050         int sw = enable;
00051         
00052         if( (sw == 0) && (before_sw == 1) )
00053         {
00054             if( rec_flag )
00055             {
00056                 rec_flag = false;
00057                 fclose(fp);
00058                 fp = NULL;
00059             }
00060             else
00061             {
00062                 rec_flag = true;
00063                 fp = fopen("/fs/gps.log", "w");
00064             }
00065             wait(0.2);
00066         }
00067         before_sw = sw;
00068 
00069         if(gps.readable()) {
00070             tmp = gps.getc();
00071             data[num] = tmp;
00072             if( data[num] == '$' ) {
00073                 data[0] = '$';
00074                 num = 1;
00075             }
00076             else if( data[num-1] == '\r' && data[num] == '\n' ) {
00077             
00078                 if(rec_flag)    rx_status = !rx_status;
00079 
00080                 data[num+1] = '\0';
00081 
00082                 if(memcmp(data, "$GPRMC",6) == 0) {
00083                                 
00084                     if(pps_count >= 5) {
00085                         pps_count = 0;
00086                     
00087                         if( fp != NULL ) {
00088                             sd_access =! sd_access;
00089                             fprintf(fp,"%s",data);
00090                         }
00091 
00092                     }
00093                     if(rec_flag)    deepsleep();
00094                 }
00095                 data[0] = '\0';
00096                 num = 0;
00097             }
00098             else {
00099                 num++;
00100                 if(num > 80)
00101                 {
00102                     num = 0;
00103                 }
00104             }
00105         }
00106     }
00107 }