Adding invertPowerPin. Updating Example101 after testing on the MM Asset Tracker CB

Author: PaulZC

examples/Example101_GNSS_GPRMC/Example101_GNSS_GPRMC.ino

@@ -8,15 +8,9 @@
 
   This example demonstrates how to use the gpsGetRmc feature.
 
-  This code is intend to run on the MicroMod Asset Tracker Carrier Board
-  using (e.g.) the MicroMod Artemis Processor Board
-
-  Select the SparkFun RedBoard Artemis ATP from the SparkFun Apollo3 boards
-  
 */
 
-//Click here to get the library: http://librarymanager/All#SparkFun_u-blox_SARA-R5_Arduino_Library
-#include <SparkFun_u-blox_SARA-R5_Arduino_Library.h>
+#include <SparkFun_u-blox_SARA-R5_Arduino_Library.h> //Click here to get the library: http://librarymanager/All#SparkFun_u-blox_SARA-R5_Arduino_Library
 
 // Uncomment the next line to connect to the SARA-R5 using hardware Serial1
 #define saraSerial Serial1
@@ -28,14 +22,20 @@
 // Usually we would tell the library which GPIO pin to use to control the SARA power (see below),
 // but we can start the SARA without a power pin. It just means we need to use a finger to 
 // turn the power on manually if required! ;-D
-SARA_R5 assetTracker;
+SARA_R5 mySARA;
 
 // Create a SARA_R5 object to use throughout the sketch
 // We need to tell the library what GPIO pin is connected to the SARA power pin.
 // If you're using the MicroMod Asset Tracker and the MicroMod Artemis Processor Board,
-// the pin number is GPIO2 which is connected to AD34. TO DO: Check this!
+// the pin name is G2 which is connected to pin AD34.
+// Change the pin number if required.
+//SARA_R5 mySARA(34);
+
+// If you're using the MicroMod Asset Tracker then we need to define which pin controls the active antenna power.
+// If you're using the MicroMod Artemis Processor Board, the pin name is G6 which is connected to pin D14.
 // Change the pin number if required.
-//SARA_R5 assetTracker(34);
+//const int antennaPowerEnablePin = 14; // Uncomment this line to define the pin number for the antenna power enable
+const int antennaPowerEnablePin = -1; // Uncomment this line if your board does not have an antenna power enable
 
 PositionData gps;
 SpeedData spd;
@@ -46,41 +46,56 @@ boolean valid;
 unsigned long lastGpsPoll = 0;
 
 void setup() {
-  Serial.begin(9600);
+  Serial.begin(115200);
 
   // Wait for user to press key in terminal to begin
-  Serial.println("Press any key to begin GPS'ing");
+  Serial.println(F("SARA-R5 Example"));
+  Serial.println(F("Press any key to begin GPS'ing"));
   while (!Serial.available()) ;
   while (Serial.available()) Serial.read();
 
+  //mySARA.enableDebugging(); // Uncomment this line to enable helpful debug messages
+
+  // For the Asset Tracker, we need to invert the power pin so it pulls high instead of low
+  // Comment the next line if required
+  mySARA.invertPowerPin(true); 
+
   // Initialize the SARA
-  if (assetTracker.begin(saraSerial, 9600) ) {
-    Serial.println(F("Asset Tracker (SARA-R5) connected!"));
+  if (mySARA.begin(saraSerial, 9600) ) {
+    Serial.println(F("SARA-R5 connected!"));
   }
 
   // Enable the GPS's RMC sentence output. This will also turn the
-  // GPS module on ((assetTracker.gpsPower(true)) if it's not already
-  if (assetTracker.gpsEnableRmc(true) != SARA_R5_SUCCESS) {
+  // GPS module on ((mySARA.gpsPower(true)) if it's not already
+  if (mySARA.gpsEnableRmc(true) != SARA_R5_SUCCESS) {
     Serial.println(F("Error initializing GPS. Freezing..."));
     while (1) ;
   }
+
+  // Enable power for the GNSS active antenna
+  enableGNSSAntennaPower();
 }
 
 void loop() {
-  if ((lastGpsPoll == 0) || (lastGpsPoll + GPS_POLL_RATE < millis())) {
-    // Call (assetTracker.gpsGetRmc to get coordinate, speed, and timing data
+  if ((lastGpsPoll == 0) || (lastGpsPoll + GPS_POLL_RATE < millis()))
+  {
+    // Call (mySARA.gpsGetRmc to get coordinate, speed, and timing data
     // from the GPS module. Valid can be used to check if the GPS is
     // reporting valid data
-    if (assetTracker.gpsGetRmc(&gps, &spd, &clk, &valid) == SARA_R5_SUCCESS) {
+    if (mySARA.gpsGetRmc(&gps, &spd, &clk, &valid) == SARA_R5_SUCCESS)
+    {
       printGPS();
       lastGpsPoll = millis();
-    } else {
+    }
+    else
+    {
       delay(1000); // If RMC read fails, wait a second and try again
     }
   }
 }
 
-void printGPS(void) {
+void printGPS(void)
+{
   Serial.println();
   Serial.println("UTC: " + String(gps.utc));
   Serial.print("Time: ");
@@ -95,10 +110,29 @@ void printGPS(void) {
   Serial.println("Latitude: " + String(gps.lat, 7));
   Serial.println("Longitude: " + String(gps.lon, 7));
   Serial.println("Speed: " + String(spd.speed, 4) + " @ " + String(spd.cog, 4));
-  Serial.println("Date: " + String(clk.date.month) + "/" + 
+  Serial.println("Date (MM/DD/YY): " + String(clk.date.month) + "/" + 
     String(clk.date.day) + "/" + String(clk.date.year));
   Serial.println("Magnetic variation: " + String(spd.magVar));
   Serial.println("Status: " + String(gps.status));
   Serial.println("Mode: " + String(gps.mode));
   Serial.println();
 }
+
+// Disable power for the GNSS active antenna
+void disableGNSSAntennaPower()
+{
+  if (antennaPowerEnablePin >= 0)
+  {
+    pinMode(antennaPowerEnablePin, OUTPUT);
+    digitalWrite(antennaPowerEnablePin, LOW);
+  }
+}
+// Enable power for the GNSS active antenna
+void enableGNSSAntennaPower()
+{
+  if (antennaPowerEnablePin >= 0)
+  {
+    pinMode(antennaPowerEnablePin, OUTPUT);
+    digitalWrite(antennaPowerEnablePin, HIGH);
+  }
+}

src/SparkFun_u-blox_SARA-R5_Arduino_Library.cpp

@@ -16,8 +16,6 @@
 
 #include <SparkFun_u-blox_SARA-R5_Arduino_Library.h>
 
-static boolean parseGPRMCString(char *rmcString, PositionData *pos, ClockData *clk, SpeedData *spd);
-
 SARA_R5::SARA_R5(int powerPin, int resetPin, uint8_t maxInitDepth)
 {
 #ifdef SARA_R5_SOFTWARE_SERIAL_ENABLED
@@ -27,6 +25,7 @@ SARA_R5::SARA_R5(int powerPin, int resetPin, uint8_t maxInitDepth)
     _baud = 0;
     _resetPin = resetPin;
     _powerPin = powerPin;
+    _invertPowerPin = false;
     _maxInitDepth = maxInitDepth;
     _socketReadCallback = NULL;
     _socketCloseCallback = NULL;
@@ -1993,14 +1992,26 @@ SARA_R5_error_t SARA_R5::init(unsigned long baud,
     return SARA_R5_ERROR_SUCCESS;
 }
 
+void SARA_R5::invertPowerPin(boolean invert)
+{
+  _invertPowerPin = invert;
+}
+
 void SARA_R5::powerOn(void)
 {
   if (_powerPin >= 0)
   {
+    if (_invertPowerPin) // Set the pin state before making it an output
+      digitalWrite(_powerPin, HIGH);
+    else
+      digitalWrite(_powerPin, LOW);
     pinMode(_powerPin, OUTPUT);
-    digitalWrite(_powerPin, LOW);
+    if (_invertPowerPin) // Set the pin state
+      digitalWrite(_powerPin, HIGH);
+    else
+      digitalWrite(_powerPin, LOW);
     delay(SARA_R5_POWER_PULSE_PERIOD);
-    pinMode(_powerPin, INPUT); // Return to high-impedance, rely on SARA module internal pull-up
+    pinMode(_powerPin, INPUT); // Return to high-impedance, rely on (e.g.) SARA module internal pull-up
     delay(2000);               //Wait before sending AT commands to module. 100 is too short.
     if (_printDebug == true) _debugPort->println(F("Power cycle complete."));
   }
@@ -2595,7 +2606,7 @@ void SARA_R5::pruneBacklog()
 // GPS Helper Functions:
 
 // Read a source string until a delimiter is hit, store the result in destination
-static char *readDataUntil(char *destination, unsigned int destSize,
+char *SARA_R5::readDataUntil(char *destination, unsigned int destSize,
                            char *source, char delimiter)
 {
 
@@ -2614,15 +2625,19 @@ static char *readDataUntil(char *destination, unsigned int destSize,
     return strEnd;
 }
 
-#define TEMP_NMEA_DATA_SIZE 16
-
-static boolean parseGPRMCString(char *rmcString, PositionData *pos,
+boolean SARA_R5::parseGPRMCString(char *rmcString, PositionData *pos,
                                 ClockData *clk, SpeedData *spd)
 {
     char *ptr, *search;
     unsigned long tTemp;
     char tempData[TEMP_NMEA_DATA_SIZE];
 
+    if (_printDebug == true)
+    {
+      _debugPort->println(F("parseGPRMCString: rmcString: "));
+      _debugPort->println(rmcString);
+    }
+
     // Fast-forward test to first value:
     ptr = strchr(rmcString, ',');
     ptr++; // Move ptr past first comma
@@ -2670,7 +2685,7 @@ static boolean parseGPRMCString(char *rmcString, PositionData *pos,
     {
         pos->lat = atof(tempData); // Extract ddmm.mmmmm as float
         unsigned long lat_deg = pos->lat / 100; // Extract the degrees
-        pos->lat -= (float)lat_deg * 60.0; // Subtract the degrees leaving only the minutes
+        pos->lat -= (float)lat_deg * 100.0; // Subtract the degrees leaving only the minutes
         pos->lat /= 60.0; // Convert minutes into degrees
         pos->lat += (float)lat_deg; // Finally add the degrees back on again
     }
@@ -2679,6 +2694,7 @@ static boolean parseGPRMCString(char *rmcString, PositionData *pos,
         pos->lat = 0.0;
     }
     ptr = search + 1;
+
     // Find latitude hemishpere
     search = readDataUntil(tempData, TEMP_NMEA_DATA_SIZE, ptr, ',');
     if ((search != NULL) && (search == ptr + 1))
@@ -2694,7 +2710,7 @@ static boolean parseGPRMCString(char *rmcString, PositionData *pos,
     {
       pos->lon = atof(tempData); // Extract dddmm.mmmmm as float
       unsigned long lon_deg = pos->lon / 100; // Extract the degrees
-      pos->lon -= (float)lon_deg * 60.0; // Subtract the degrees leaving only the minutes
+      pos->lon -= (float)lon_deg * 100.0; // Subtract the degrees leaving only the minutes
       pos->lon /= 60.0; // Convert minutes into degrees
       pos->lon += (float)lon_deg; // Finally add the degrees back on again
     }
@@ -2703,7 +2719,8 @@ static boolean parseGPRMCString(char *rmcString, PositionData *pos,
         pos->lon = 0.0;
     }
     ptr = search + 1;
-    // Find latitude hemishpere
+
+    // Find longitude hemishpere
     search = readDataUntil(tempData, TEMP_NMEA_DATA_SIZE, ptr, ',');
     if ((search != NULL) && (search == ptr + 1))
     {
@@ -2724,6 +2741,7 @@ static boolean parseGPRMCString(char *rmcString, PositionData *pos,
         spd->speed = 0.0;
     }
     ptr = search + 1;
+
     // Find course over ground
     search = readDataUntil(tempData, TEMP_NMEA_DATA_SIZE, ptr, ',');
     if ((search != NULL) && (search != ptr))
@@ -2766,6 +2784,7 @@ static boolean parseGPRMCString(char *rmcString, PositionData *pos,
         spd->magVar = 0.0;
     }
     ptr = search + 1;
+    
     // Find magnetic variation direction
     search = readDataUntil(tempData, TEMP_NMEA_DATA_SIZE, ptr, ',');
     if ((search != NULL) && (search == ptr + 1))

src/SparkFun_u-blox_SARA-R5_Arduino_Library.h

@@ -118,6 +118,9 @@ const char SARA_R5_RESPONSE_ERROR[] = "ERROR\r\n";
 const char ASCII_CTRL_Z = 0x1A;
 const char ASCII_ESC = 0x1B;
 
+// NMEA data size - used by parseGPRMCString
+#define TEMP_NMEA_DATA_SIZE 16
+
 #define NOT_AT_COMMAND false
 #define AT_COMMAND true
 
@@ -275,6 +278,11 @@ class SARA_R5 : public Print
     // Debug prints
     void enableDebugging(Stream &debugPort = Serial); //Turn on debug printing. If user doesn't specify then Serial will be used.
 
+    // Invert the polarity of the power pin - if required
+    // Normally the SARA's power pin is pulled low and released to toggle the power
+    // But the Asset Tracker needs this to be pulled high and released instead
+    void invertPowerPin(boolean invert = false);
+
     // Loop polling and polling setup
     boolean bufferedPoll(void);
 	  boolean processReadEvent(char* event);
@@ -466,6 +474,8 @@ class SARA_R5 : public Print
 
     int _powerPin;
     int _resetPin;
+    boolean _invertPowerPin = false;
+
     unsigned long _baud;
     IPAddress _lastRemoteIP;
     IPAddress _lastLocalIP;
@@ -533,6 +543,11 @@ class SARA_R5 : public Print
     char *sara_r5_calloc_char(size_t num);
 
     void pruneBacklog(void);
+
+    // GPS Helper functions
+    char *readDataUntil(char *destination, unsigned int destSize, char *source, char delimiter);
+    boolean parseGPRMCString(char *rmcString, PositionData *pos, ClockData *clk, SpeedData *spd);
+
 };
 
 #endif //SPARKFUN_SARA_R5_ARDUINO_LIBRARY_H