Revision 0:81d4b52c0083, committed 2021-01-15

Comitter:

ctlee

Date:

Fri Jan 15 13:21:24 2021 +0000

Commit message:

nothing

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stm32l475e_iot01_gps.cpp	Fri Jan 15 13:21:24 2021 +0000
@@ -0,0 +1,171 @@
+
+#include "stm32l475e_iot01_gps.h"
+#include <stdio.h>
+#include <string.h>
+ 
+Serial pc1(USBTX, USBRX);
+ 
+GPS::GPS(PinName tx, PinName rx) : _gps(tx, rx) {
+    _gps.baud(9600);
+      
+    longitude = 0.0;
+    latitude = 0.0;
+    ns = 'N';
+    ew = 'E';
+    alt = 0.0;
+            
+}
+
+int GPS::sample() {
+    float time, knots, angle, mag, mag_angle;
+    int date, checksum;
+   
+    char lock;
+    
+    while(1) {        
+        getline();
+        // Check if it is a GPGGA msg (matches both locked and non-locked msg)
+        //pc1.printf(msg);
+        pc1.printf("\n");
+        wait(5);
+        pc1.printf("display msg\r\n");
+        pc1.printf(msg);
+        pc1.printf("\n");
+        if(sscanf(msg, "GPRMC,%f,%c,%f,%c,%f,%c,%f,%f,%d,%f,%f*%d", &time, &lock, &latitude, &ns, &longitude, &ew, &knots, &angle, &date, &mag, &mag_angle, &checksum) >= 1) { 
+            if(lock=='V') {
+                pc1.printf("not valid!!!!!!!\n");
+                longitude = 0.0;
+                latitude = 0.0;  
+                ns = 'Z';
+                ew = 'Z';
+                date =0;      
+                return 0;
+            } else {
+                //if(ns == 'S') {    latitude  *= -1.0; }
+//                if(ew == 'W') {    longitude *= -1.0; }
+//                float degrees = trunc(latitude / 100.0f);
+//                float minutes = latitude - (degrees * 100.0f);
+//                latitude = degrees + minutes / 60.0f;    
+//                degrees = trunc(longitude / 100.0f * 0.01f);
+//                minutes = longitude - (degrees * 100.0f);
+//                longitude = degrees + minutes / 60.0f;
+//                pc1.printf(msg);
+                pc1.printf("\n\rlongitude is %f\n\r", longitude);
+                pc1.printf("\n\rtime is %f\n\r", time);
+                pc1.printf("ns is %c\n\r", ns);
+                pc1.printf("ew is %c\n\r", ew);
+                pc1.printf("alt is %d\n\r", date);
+                
+                latitude /= 100;
+                longitude /= 100;
+                
+                return 1;
+            }
+        
+        }
+        return 0;
+    }
+}
+ 
+float GPS::trunc(float v) {
+    if(v < 0.0) {
+        v*= -1.0;
+        v = floor(v);
+        v*=-1.0;
+    } else {
+        v = floor(v);
+    }
+    return v;
+}
+ 
+void GPS::getline() {
+    int i;
+    char a;
+    int n;
+    while(1) {
+    memset(msg, '\0', sizeof(msg));
+    pc1.printf("\r\n\n New Message: ");
+    pc1.printf(msg);
+    pc1.printf("\r\n\n");    
+    i = 0;
+    pc1.printf("waiting...\n");
+    a = _gps.getc();
+    msg[i] = a;
+    if (a == '$') {
+        pc1.printf("%c",a);
+        msg[i]=a;
+        a = _gps.getc();
+        while(a!='$'){
+            msg[i] = a;
+            i++;            
+            printf("%c",a);
+            a = _gps.getc();
+        }
+        return;
+//        msg[i] = a;
+//        i++;
+//        if (a == 'G') {
+//            pc1.printf("%c",a);
+//            a = _gps.getc();
+//            msg[i] = a;
+//            i++;
+//            if (a == 'P') {
+//                pc1.printf("%c",a);
+//                a = _gps.getc();
+//                msg[i] = a;
+//                i++;
+//                if (a == 'R') {
+//                    pc1.printf("%c",a);
+//                    a = _gps.getc();
+//                    msg[i] = a;
+//                    i++;
+//                    if (a == 'M') {
+//                        pc1.printf("%c",a);
+//                        a = _gps.getc();
+//                        msg[i] = a;
+//                        i++;
+//                        if (a == 'C') {
+//                            pc1.printf("%c",a);
+//                            a = _gps.getc();
+//                            msg[i] = a;
+//                            pc1.printf(msg);
+//                            pc1.printf("\r\n");
+//        
+//                            for (n = 5; n < 456; n++) {
+//                               msg[n] = _gps.getc();
+//                               pc1.printf("%c", msg[n]);
+//                               if(msg[n] == '\r') {
+//                                 msg[n] = '0';
+//                                 return;
+//                                }
+//                            }
+//                         }
+//                     }
+//                 }
+//            }
+//       }
+    }                          
+//    while(_gps.getc() != '$') {
+//        //char a = _gps.getc();
+//        for(i = 0; i < 256; i++) {
+//            msg[i] = _gps.getc();
+//            pc1.printf("%c", msg[i]);
+//            if(msg[i] == '\r') {
+//             msg[i] = 0;
+//             return;
+//                }
+//                }
+//          
+//         
+//    }
+//    while(_gps.getc() != '$');    // wait for the start of a line
+//    for(int i=0; i<256; i++) {
+//        msg[i] = _gps.getc();
+//        if(msg[i] == '\r') {
+//            msg[i] = 0;
+//            return;
+//        }
+//    }
+//    error("Overflowed message limit");
+}
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/stm32l475e_iot01_gps.h	Fri Jan 15 13:21:24 2021 +0000
@@ -0,0 +1,43 @@
+
+#include "mbed.h"
+ 
+#ifndef __STM32L475E_IOT01_GPS_H
+#define __STM32L475E_IOT01_GPS_H
+ 
+/**  A GPS interface for reading from a Globalsat EM-406 GPS Module */
+class GPS {
+public:
+ 
+    /** Create the GPS interface, connected to the specified serial port
+     */    
+    GPS(PinName tx, PinName rx);
+    
+    /** Sample the incoming GPS data, returning whether there is a lock
+     * 
+     * @return 1 if there was a lock when the sample was taken (and therefore .longitude and .latitude are valid), else 0
+     */
+    int sample();
+    
+    /** The longitude (call sample() to set) */
+    float longitude;
+ 
+    /** The latitude (call sample() to set) */
+    float latitude;
+    
+    int num_sat;
+    float hori_dilute;
+    float alt;
+    float geoid, time;
+    char ns, ew;
+     char gu, hu;
+     
+private:
+    float trunc(float v);
+    void getline();
+    
+    Serial _gps;
+    char msg[256];
+ 
+};
+ 
+#endif
\ No newline at end of file