Add noCRLF option to build()

new optional argument will leave the carriage return and linefeed off the end of an NMEA sentence.

src/Adafruit_GPS.cpp

@@ -349,7 +349,13 @@ size_t Adafruit_GPS::write(uint8_t c) {
 
 /**************************************************************************/
 /*!
-    @brief Read one character from the GPS device
+    @brief Read one character from the GPS device. 
+    
+    Call very frequently and multiple times per opportunity or the buffer
+    may overflow if there are frequent NMEA sentences. An 82 character NMEA
+    sentence 10 times per second will require 820 calls per second, and 
+    once a loop() may not be enough. Check for newNMEAreceived() after at
+    least every 10 calls, or you may miss some short sentences.
     @return The character that we received, or 0 if nothing was available
 */
 /**************************************************************************/

src/Adafruit_GPS.h

@@ -121,7 +121,7 @@ public:
   // NMEA_build.cpp
 #ifdef NMEA_EXTENSIONS
   char *build(char *nmea, const char *thisSource, const char *thisSentence,
-              char ref = 'R');
+              char ref = 'R', bool noCRLF = false);
 #endif
   void addChecksum(char *buff);
 

src/NMEA_build.cpp

@@ -71,7 +71,7 @@
 */
 /**************************************************************************/
 char *Adafruit_GPS::build(char *nmea, const char *thisSource,
-                          const char *thisSentence, char ref) {
+                          const char *thisSentence, char ref, bool noCRLF) {
   sprintf(nmea, "%6.2f",
           (double)123.45); // fail if sprintf() doesn't handle floats
   if (strcmp(nmea, "123.45"))
@@ -569,8 +569,9 @@ char *Adafruit_GPS::build(char *nmea, const char *thisSource,
   }
 
   addChecksum(nmea); // Successful completion
-  sprintf(nmea, "%s\r\n",
-          nmea); // Add Carriage Return and Line Feed to comply with NMEA-183
+  if (!noCRLF) { // Add Carriage Return and Line Feed to comply with NMEA-183
+    sprintf(nmea, "%s\r\n", nmea); 
+  }
   return nmea;   // return pointer to finished product
 }