Merge pull request #174 from ladyada-eagleclaw/fix-flash-gps-commands

Allow GPS commands to be stored in flash

examples/shield_sdlog/shield_sdlog.ino

@@ -117,16 +117,16 @@ void setup() {
   GPS.begin(9600);
 
   // uncomment this line to turn on RMC (recommended minimum) and GGA (fix data) including altitude
-  GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCGGA);
+  GPS.sendCommand(F(PMTK_SET_NMEA_OUTPUT_RMCGGA));
   // uncomment this line to turn on only the "minimum recommended" data
-  //GPS.sendCommand(PMTK_SET_NMEA_OUTPUT_RMCONLY);
+  //GPS.sendCommand(F(PMTK_SET_NMEA_OUTPUT_RMCONLY));
   // For logging data, we don't suggest using anything but either RMC only or RMC+GGA
   // to keep the log files at a reasonable size
   // Set the update rate
-  GPS.sendCommand(PMTK_SET_NMEA_UPDATE_1HZ);   // 100 millihertz (once every 10 seconds), 1Hz or 5Hz update rate
+  GPS.sendCommand(F(PMTK_SET_NMEA_UPDATE_1HZ));   // 100 millihertz (once every 10 seconds), 1Hz or 5Hz update rate
 
   // Turn off updates on antenna status, if the firmware permits it
-  GPS.sendCommand(PGCMD_NOANTENNA);
+  GPS.sendCommand(F(PGCMD_NOANTENNA));
 
   // the nice thing about this code is you can have a timer0 interrupt go off
   // every 1 millisecond, and read data from the GPS for you. that makes the

src/Adafruit_GPS.cpp

@@ -392,6 +392,14 @@ char Adafruit_GPS::read(void) {
 /**************************************************************************/
 void Adafruit_GPS::sendCommand(const char *str) { println(str); }
 
+/**************************************************************************/
+/*!
+    @brief Send a command stored in flash
+    @param str Command wrapped in F()
+*/
+/**************************************************************************/
+void Adafruit_GPS::sendCommand(const __FlashStringHelper *str) { println(str); }
+
 /**************************************************************************/
 /*!
     @brief Check to see if a new NMEA line has been received

src/Adafruit_GPS.h

@@ -101,6 +101,7 @@ public:
   size_t write(uint8_t);
   char read(void);
   void sendCommand(const char *);
+  void sendCommand(const __FlashStringHelper *);
   bool newNMEAreceived();
   void pause(bool b);
   char *lastNMEA(void);